1
|
Luo Y, Wang Y, Qiu F, Hou G, Liu J, Yang H, Wu M, Dong X, Guo D, Zhong Z, Zhang X, Ge J, Meng P. Ablated Sonic Hedgehog Signaling in the Dentate Gyrus of the Dorsal and Ventral Hippocampus Impairs Hippocampal-Dependent Memory Tasks and Emotion in a Rat Model of Depression. Mol Neurobiol 2024; 61:4352-4368. [PMID: 38087166 DOI: 10.1007/s12035-023-03796-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 11/08/2023] [Indexed: 07/11/2024]
Abstract
Specific memory processes and emotional aberrations in depression can be attributed to the different dorsal-ventral regions of the hippocampus. However, the molecular mechanisms underlying the differential functions of the dorsal hippocampus (dHip) and ventral hippocampus (vHip) remain unclear. As Sonic Hedgehog (Shh) is involved in the dorsal-ventral patterning of the neural tube and its signaling is dysregulated by chronic unpredictable mild stress (CUMS), we investigated its role in influencing the differential functions of the dHip and vHip. Here, CUMS downregulated the expression of Shh signaling markers, including Shh and its downstream effectors GLI family zinc finger 12 (Gli1/2), Patched (Ptch), and smoothened (Smo), in both the dHip and vHip of rats, though more so in the vHip. Additionally, Shh knockdown in the dorsal or ventral dentate gyrus (DG) resulted in restrained neurogenic activity in newborn neurons, especially in immature neurons through decreased expression of Shh signaling markers. Furthermore, Shh knockdown in the DG of the dHip led to memory impairment by inhibiting experience-dependent activation of immature neurons, whereas its knockdown in the DG of the vHip led to an emotional handicap by delaying the maturation of immature neurons. Finally, Shh knockdown in either the dDG or vDG of hippocampus abolished the corresponding cognitive enhancement and emotional recovery of fluoxetine. In conclusion, Shh is essential to maintain the functional heterogeneity of dHip and vHip in depressed rat, which was mainly mediating by local changes of dependent activation and maturity of immature neurons, respectively.
Collapse
Affiliation(s)
- Yan Luo
- Hunan University of Chinese Medicine, Changsha, 410208, Hunan, China
| | - Yan Wang
- Yiyang Central Hospital, Yiyang, 413000, Hunan, China
| | - Feng Qiu
- Hunan University of Chinese Medicine, Changsha, 410208, Hunan, China
| | - Guanghan Hou
- Fourth Hospital of Changsha, Hunan, 410000, China
| | - Jian Liu
- Hunan University of Chinese Medicine, Changsha, 410208, Hunan, China
- First Affiliated Hospital, Hunan University of Chinese Medicine, Changsha, 410007, Hunan, China
| | - Hui Yang
- Hunan University of Chinese Medicine, Changsha, 410208, Hunan, China
- First Affiliated Hospital, Hunan University of Chinese Medicine, Changsha, 410007, Hunan, China
| | - Mei Wu
- Hunan University of Chinese Medicine, Changsha, 410208, Hunan, China
| | - Xuanqi Dong
- The Second People's Hospital of Hunan Province, Changsha, 410000, Hunan, China
| | - Dongwei Guo
- The Second People's Hospital of Hunan Province, Changsha, 410000, Hunan, China
| | - Ziyan Zhong
- Hunan University of Chinese Medicine, Changsha, 410208, Hunan, China
| | - Xi Zhang
- The Second People's Hospital of Hunan Province, Changsha, 410000, Hunan, China.
| | - Jinwen Ge
- Hunan Academy of Chinese Medicine, Changsha, 410300, Hunan, China.
| | - Pan Meng
- Hunan University of Chinese Medicine, Changsha, 410208, Hunan, China.
| |
Collapse
|
2
|
Granato V, Congiu L, Jakovcevski I, Kleene R, Schwindenhammer B, Fernandes L, Freitag S, Schachner M, Loers G. Mice Mutated in the First Fibronectin Domain of Adhesion Molecule L1 Show Brain Malformations and Behavioral Abnormalities. Biomolecules 2024; 14:468. [PMID: 38672483 PMCID: PMC11048097 DOI: 10.3390/biom14040468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/18/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
The X-chromosome-linked cell adhesion molecule L1 (L1CAM), a glycoprotein mainly expressed by neurons in the central and peripheral nervous systems, has been implicated in many neural processes, including neuronal migration and survival, neuritogenesis, synapse formation, synaptic plasticity and regeneration. L1 consists of extracellular, transmembrane and cytoplasmic domains. Proteolytic cleavage of L1's extracellular and transmembrane domains by different proteases generates several L1 fragments with different functions. We found that myelin basic protein (MBP) cleaves L1's extracellular domain, leading to enhanced neuritogenesis and neuronal survival in vitro. To investigate in vivo the importance of the MBP-generated 70 kDa fragment (L1-70), we generated mice with an arginine to alanine substitution at position 687 (L1/687), thereby disrupting L1's MBP cleavage site and obliterating L1-70. Young adult L1/687 males showed normal anxiety and circadian rhythm activities but enhanced locomotion, while females showed altered social interactions. Older L1/687 males were impaired in motor coordination. Furthermore, L1/687 male and female mice had a larger hippocampus, with more neurons in the dentate gyrus and more proliferating cells in the subgranular layer, while the thickness of the corpus callosum and the size of lateral ventricles were normal. In summary, subtle mutant morphological changes result in subtle behavioral changes.
Collapse
Affiliation(s)
- Viviana Granato
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| | - Ludovica Congiu
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| | - Igor Jakovcevski
- Institut für Anatomie und Klinische Morphologie, Universität Witten/Herdecke, 58455 Witten, Germany; (I.J.); (B.S.)
- Department of Neuroanatomy and Molecular Brain Research, Institute of Anatomy, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Ralf Kleene
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| | - Benjamin Schwindenhammer
- Institut für Anatomie und Klinische Morphologie, Universität Witten/Herdecke, 58455 Witten, Germany; (I.J.); (B.S.)
- Department of Neuroanatomy and Molecular Brain Research, Institute of Anatomy, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Luciana Fernandes
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| | - Sandra Freitag
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| | - Melitta Schachner
- Keck Center for Collaborative Neuroscience, Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08554, USA
| | - Gabriele Loers
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| |
Collapse
|
3
|
Mohammadi M, Tavassoli Z, Anvari S, Javan M, Fathollahi Y. Avoidance and escape conditioning adjust adult neurogenesis to conserve a fit hippocampus in adult male rodents. J Neurosci Res 2024; 102:e25291. [PMID: 38284841 DOI: 10.1002/jnr.25291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 12/04/2023] [Accepted: 12/13/2023] [Indexed: 01/30/2024]
Abstract
In this study, the connection between cognitive behaviors and the adult rodent hippocampus was investigated. Recording field potentials at performant pathway (PP)-hippocampal dentate gyrus (DG) synapses in transverse slices from the dorsal (d), intermediate (i), and ventral (v) hippocampus showed differences in paired-pulse responses and long-term potentiation in rats. The Barnes maze (BM) and passive avoidance (PA) tests indicated a decrease in escape latency and step-through latency in both rats and mice over training days. A decrease in the use of random or sequential strategy while an increase in the use of direct strategy to search for an escape box occurred in both groups. Evaluation of the levels of neurogenesis markers (Ki67 and BrdU/NeuN) by immunofluorescence assay in the dDG, iDG, and vDG revealed a long-axis disparity in the hippocampal dentate baseline cell proliferation and exposure to the BM and PA task changed the profile of baseline cell proliferation along the DG in both rats and mice. Also, these learning experiences changed the profile of BrdU+ /NeuN+ cells along the DG of rats. Quantitation of hippocampal BDNF protein levels using ELISA exhibited no changes in BDNF levels due to learning experiences in rats. We demonstrate that PP-DG synaptic efficacy and neurogenesis are organized along a gradient. Avoidance and escape conditioning themselves are sufficient to change and calibrate adult neurogenesis along the hippocampal long axis in rodents. Further research will be required to determine the precise mechanisms underlying the role of experience-derived neuroplasticity in cognitive function and decline.
Collapse
Affiliation(s)
- Masoud Mohammadi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Zohreh Tavassoli
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Sohrab Anvari
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Javan
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Yaghoub Fathollahi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| |
Collapse
|
4
|
Male Stressed Mice Having Behavioral Control Exhibit Escalations in Dorsal Dentate Adult-Born Neurons and Spatial Memory. Int J Mol Sci 2023; 24:ijms24031983. [PMID: 36768303 PMCID: PMC9916676 DOI: 10.3390/ijms24031983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023] Open
Abstract
An escapable (ES)/inescapable stress (IS) paradigm was used to study whether behavioral control and repeated footshock stressors may affect adult neurogenesis and related cognitive function. Male stressed mice having behavioral control (ES) had a short-term escalation in dorsal dentate gyrus (DG) neurogenesis, while similarly stressed mice having no such control had unaltered neurogenesis as compared to control mice receiving no stressors. Paradoxically, ES and IS mice had comparable stress-induced corticosterone elevations throughout the stress regimen. Appetitive operant conditioning and forced running procedures were used to model learning and exercise effects in this escapable/inescapable paradigm. Further, conditioning and running procedures did not seem to affect the mice's corticosterone or short-term neurogenesis. ES and IS mice did not show noticeable long-term changes in their dorsal DG neurogenesis, gliogenesis, local neuronal density, apoptosis, autophagic flux, or heterotypic stress responses. ES mice were found to have a greater number of previously labeled and functionally integrated DG neurons as compared to IS and control mice 6 weeks after the conclusion of the stressor regimen. Likewise, ES mice outperformed IS and non-stressed control mice for the first two, but not the remaining two, trials in the object location task. Compared to non-stressed controls, temozolomide-treated ES and IS mice having a lower number of dorsal DG 6-week-old neurons display poor performance in their object location working memory. These results, taken together, prompt us to conclude that repeated stressors, albeit their corticosterone secretion-stimulating effect, do not necessary affect adult dorsal DG neurogenesis. Moreover, stressed animals having behavioral control may display adult neurogenesis escalation in the dorsal DG. Furthermore, the number of 6-week-old and functionally-integrated neurons in the dorsal DG seems to confer the quality of spatial location working memory. Finally, these 6-week-old, adult-born neurons seem to contribute spatial location memory in a use-dependent manner.
Collapse
|
5
|
Yagi S, Lee A, Truter N, Galea LAM. Sex differences in contextual pattern separation, neurogenesis, and functional connectivity within the limbic system. Biol Sex Differ 2022; 13:42. [PMID: 35870952 PMCID: PMC9308289 DOI: 10.1186/s13293-022-00450-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 07/05/2022] [Indexed: 01/04/2023] Open
Abstract
Background Females are more likely to present with anxiety disorders such as post-traumatic stress disorder (PTSD) compared to males, which are associated with disrupted hippocampal integrity. Sex differences in the structure and function of hippocampus exist. Here, we examined sex differences in contextual pattern separation, functional connectivity, and activation of new neurons during fear memory. Methods Two-month-old male and female Sprague-Dawley rats were injected with the DNA synthesis markers, iododeoxyuridine (IdU) and chlorodeoxyuridine (CldU) 3 weeks and 4 weeks before perfusion, respectively. One week after CldU injection, the rats underwent a context discrimination task in which rats were placed in context A (shock) and context A’ (no shock) every day for 12 days. On the test day, rats were placed in the shock context (context A) to measure fear memory and expression of zif268, an immediate early gene across 16 different limbic and reward regions. Repeated-measures or factorial analysis of variance was conducted on our variables of interest. Pearson product-moment calculations and principal component analyses on zif268 expression across regions were also performed. Results We found that females, but not males, showed contextual discrimination during the last days of training. On the test day, both sexes displayed similar levels of freezing, indicating equivalent fear memory for context A. Despite similar fear memory, males showed more positive correlations of zif268 activation between the limbic regions and the striatum, whereas females showed more negative correlations among these regions. Females showed greater activation of the frontal cortex, dorsal CA1, and 3-week-old adult-born dentate granular cells compared to males. Conclusions These results highlight the importance of studying sex differences in fear memory and the contribution of adult neurogenesis to the neuronal network and may contribute to differences in susceptibility to fear-related disorders such as post-traumatic stress disorder. HighlightsFemale rats, but not male rats, show faster discrimination during a contextual pattern separation task. Three-week-old adult-born neurons are more active in response to fear memory in females compared to males. Females had greater neural activation compared to males in the frontal cortex and dorsal CA1 region of the hippocampus in response to fear memory. Males and females show distinct patterns in functional connectivity for fear memory across limbic regions. Males have many positive correlations between activated new neurons of different ages between the dorsal and ventral hippocampus, while females show more correlations between activated new neurons and other limbic regions.
Supplementary Information The online version contains supplementary material available at 10.1186/s13293-022-00450-2.
Collapse
|
6
|
A Panax quinquefolius-Based Preparation Prevents the Impact of 5-FU on Activity/Exploration Behaviors and Not on Cognitive Functions Mitigating Gut Microbiota and Inflammation in Mice. Cancers (Basel) 2022; 14:cancers14184403. [PMID: 36139563 PMCID: PMC9496716 DOI: 10.3390/cancers14184403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 01/12/2023] Open
Abstract
Simple Summary Chemotherapy-related cognitive impairment (CRCI) and fatigue worsen the quality of life (QoL) of cancer patients. Multicenter studies have shown that Panax quinquefolius and vitamin C, respectively, were effective in reducing the symptoms of fatigue in treated cancer patients. We developed a behavioral C57Bl/6j mouse model to study the impact of 5-Fluorouracil (5-FU) chemotherapy on activity/fatigue, emotional reactivity and cognitive functions. We used this model to evaluate the potentially beneficial role of a Panax quinquefolius-based solution containing vitamin C (Qiseng®) or vitamin C alone in these chemotherapy side effects. We established that Qiseng® prevents the reduction in activity/exploration and symptoms of fatigue induced by 5-FU and dampens chemotherapy-induced intestinal dysbiosis and systemic inflammation. We further showed that Qiseng® decreases macrophage infiltration in the intestinal compartment, thus preventing, at least in part, the systemic elevation of IL-6 and MCP-1 and further reducing the neuroinflammation likely responsible for the fatigue induced by chemotherapy, a major advance toward improving the QoL of patients. Abstract Chemotherapy-related cognitive impairment (CRCI) and fatigue constitute common complaints among cancer patient survivors. Panax quinquefolius has been shown to be effective against fatigue in treated cancer patients. We developed a behavioral C57Bl/6j mouse model to study the role of a Panax quinquefolius-based solution containing vitamin C (Qiseng®) or vitamin C alone in activity/fatigue, emotional reactivity and cognitive functions impacted by 5-Fluorouracil (5-FU) chemotherapy. 5-FU significantly reduces the locomotor/exploration activity potentially associated with fatigue, evokes spatial cognitive impairments and leads to a decreased neurogenesis within the hippocampus (Hp). Qiseng® fully prevents the impact of chemotherapy on activity/fatigue and on neurogenesis, specifically in the ventral Hp. We observed that the chemotherapy treatment induces intestinal damage and inflammation associated with increased levels of Lactobacilli in mouse gut microbiota and increased expression of plasma pro-inflammatory cytokines, notably IL-6 and MCP-1. We demonstrated that Qiseng® prevents the 5-FU-induced increase in Lactobacilli levels and further compensates the 5-FU-induced cytokine release. Concomitantly, in the brains of 5-FU-treated mice, Qiseng® partially attenuates the IL-6 receptor gp130 expression associated with a decreased proliferation of neural stem cells in the Hp. In conclusion, Qiseng® prevents the symptoms of fatigue, reduced chemotherapy-induced neuroinflammation and altered neurogenesis, while regulating the mouse gut microbiota composition, thus protecting against intestinal and systemic inflammation.
Collapse
|
7
|
Mateus-Pinheiro A, Patrício P, Alves ND, Martins-Macedo J, Caetano I, Silveira-Rosa T, Araújo B, Mateus-Pinheiro M, Silva-Correia J, Sardinha VM, Loureiro-Campos E, Rodrigues AJ, Oliveira JF, Bessa JM, Sousa N, Pinto L. Hippocampal cytogenesis abrogation impairs inter-regional communication between the hippocampus and prefrontal cortex and promotes the time-dependent manifestation of emotional and cognitive deficits. Mol Psychiatry 2021; 26:7154-7166. [PMID: 34521994 DOI: 10.1038/s41380-021-01287-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 08/18/2021] [Accepted: 08/26/2021] [Indexed: 02/08/2023]
Abstract
Impaired ability to generate new cells in the adult brain has been linked to deficits in multiple emotional and cognitive behavioral domains. However, the mechanisms by which abrogation of adult neural stem cells (NSCs) impacts on brain function remains controversial. We used a transgenic rat line, the GFAP-Tk, to selectively eliminate NSCs and assess repercussions on different behavioral domains. To assess the functional importance of newborn cells in specific developmental stages, two parallel experimental timeframes were adopted: a short- and a long-term timeline, 1 and 4 weeks after the abrogation protocol, respectively. We conducted in vivo electrophysiology to assess the effects of cytogenesis abrogation on the functional properties of the hippocampus and prefrontal cortex, and on their intercommunication. Adult brain cytogenesis abrogation promoted a time-specific installation of behavioral deficits. While the lack of newborn immature hippocampal neuronal and glial cells elicited a behavioral phenotype restricted to hyperanxiety and cognitive rigidity, specific abrogation of mature new neuronal and glial cells promoted the long-term manifestation of a more complex behavioral profile encompassing alterations in anxiety and hedonic behaviors, along with deficits in multiple cognitive modalities. More so, abrogation of 4 to 7-week-old cells resulted in impaired electrophysiological synchrony of neural theta oscillations between the dorsal hippocampus and the medial prefrontal cortex, which are likely to contribute to the described long-term cognitive alterations. Hence, this work provides insight on how newborn neurons and astrocytes display different functional roles throughout different maturation stages, and establishes common ground to reconcile contrasting results that have marked this field.
Collapse
Affiliation(s)
- António Mateus-Pinheiro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal.,Department of Internal Medicine, Coimbra Hospital and University Center, Coimbra, Portugal
| | - Patrícia Patrício
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Nuno Dinis Alves
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal.,Department of Psychiatry, Columbia University, New York, NY, 10032, USA.,New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Joana Martins-Macedo
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Inês Caetano
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Tiago Silveira-Rosa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Bruna Araújo
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Miguel Mateus-Pinheiro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
| | - Joana Silva-Correia
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Vanessa Morais Sardinha
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Eduardo Loureiro-Campos
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Ana João Rodrigues
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - João Filipe Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal.,DIGARC, Polytechnic Institute of Cávado and Ave, Barcelos, Portugal
| | - João M Bessa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Luísa Pinto
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal. .,ICVS/3B's-PT Government Associate Laboratory, Braga, Guimarães, Portugal.
| |
Collapse
|
8
|
Short high fat diet triggers reversible and region specific effects in DCX + hippocampal immature neurons of adolescent male mice. Sci Rep 2021; 11:21499. [PMID: 34728755 PMCID: PMC8563989 DOI: 10.1038/s41598-021-01059-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 10/18/2021] [Indexed: 11/26/2022] Open
Abstract
Adolescence represents a crucial period for maturation of brain structures involved in cognition. Early in life unhealthy dietary patterns are associated with inferior cognitive outcomes at later ages; conversely, healthy diet is associated with better cognitive results. In this study we analyzed the effects of a short period of hypercaloric diet on newborn hippocampal doublecortin+ (DCX) immature neurons in adolescent mice. Male mice received high fat diet (HFD) or control low fat diet (LFD) from the 5th week of age for 1 or 2 weeks, or 1 week HFD followed by 1 week LFD. After diet supply, mice were either perfused for immunohistochemical (IHC) analysis or their hippocampi were dissected for biochemical assays. Detailed morphometric analysis was performed in DCX+ cells that displayed features of immature neurons. We report that 1 week-HFD was sufficient to dramatically reduce dendritic tree complexity of DCX+ cells. This effect occurred specifically in dorsal and not ventral hippocampus and correlated with reduced BDNF expression levels in dorsal hippocampus. Both structural and biochemical changes were reversed by a return to LFD. Altogether these studies increase our current knowledge on potential consequences of hypercaloric diet on brain and in particular on dorsal hippocampal neuroplasticity.
Collapse
|
9
|
Westacott LJ, Haan N, Evison C, Marei O, Hall J, Hughes TR, Zaben M, Morgan BP, Humby T, Wilkinson LS, Gray WP. Dissociable effects of complement C3 and C3aR on survival and morphology of adult born hippocampal neurons, pattern separation, and cognitive flexibility in male mice. Brain Behav Immun 2021; 98:136-150. [PMID: 34403734 DOI: 10.1016/j.bbi.2021.08.215] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/15/2021] [Accepted: 08/09/2021] [Indexed: 12/14/2022] Open
Abstract
Adult hippocampal neurogenesis (AHN) is a form of ongoing plasticity in the brain that supports specific aspects of cognition. Disruptions in AHN have been observed in neuropsychiatric conditions presenting with inflammatory components and are associated with impairments in cognition and mood. Recent evidence highlights important roles of the complement system in synaptic plasticity and neurogenesis during neurodevelopment and in acute learning and memory processes. In this work we investigated the impact of the complement C3/C3aR pathway on AHN and its functional implications for AHN-related behaviours. In C3-/- mice, we found increased numbers and accelerated migration of adult born granule cells, indicating that absence of C3 leads to abnormal survival and distribution of adult born neurons. Loss of either C3 or C3aR affected the morphology of immature neurons, reducing morphological complexity, though these effects were more pronounced in the absence of C3aR. We assessed functional impacts of the cellular phenotypes in an operant spatial discrimination task that assayed AHN sensitive behaviours. Again, we observed differences in the effects of manipulating C3 or C3aR, in that whilst C3aR-/- mice showed evidence of enhanced pattern separation abilities, C3-/- mice instead demonstrated impaired behavioural flexibility. Our findings show that C3 and C3aR manipulation have distinct effects on AHN that impact at different stages in the development and maturation of newly born neurons, and that the dissociable cellular phenotypes are associated with specific alterations in AHN-related behaviours.
Collapse
Affiliation(s)
- Laura J Westacott
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - Niels Haan
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - Claudia Evison
- National Centre for Mental Health, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK
| | - Omar Marei
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK
| | - Jeremy Hall
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - Timothy R Hughes
- Complement Biology Group, Systems Immunity Research Institute, School of Medicine, Cardiff University, CF14 4XW Cardiff, UK
| | - Malik Zaben
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Brain Repair and Intracranial Neurotherapeutics (BRAIN), Biomedical Research Unit, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, CF24 4HQ, UK
| | - B Paul Morgan
- Complement Biology Group, Systems Immunity Research Institute, School of Medicine, Cardiff University, CF14 4XW Cardiff, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK; UK Dementia Research Institute, Cardiff University, Cardiff CF24 4HQ, UK
| | - Trevor Humby
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Behavioural Genetics Group, Schools of Psychology and Medicine, Cardiff University, Cardiff CF10 3AT, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - Lawrence S Wilkinson
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Behavioural Genetics Group, Schools of Psychology and Medicine, Cardiff University, Cardiff CF10 3AT, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - William P Gray
- Neuroscience and Mental Health Research Institute, MRC Centre for Neuropsychiatric Genetic and Genomics, School of Medicine, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK; Hodge Centre for Neuropsychiatric Immunology, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK; Brain Repair and Intracranial Neurotherapeutics (BRAIN), Biomedical Research Unit, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, CF24 4HQ, UK.
| |
Collapse
|
10
|
Wei M, Feng S, Zhang L, Wang C, Chu S, Shi T, Zhou W, Zhang Y. Active Fraction Combination From Liuwei Dihuang Decoction Improves Adult Hippocampal Neurogenesis and Neurogenic Microenvironment in Cranially Irradiated Mice. Front Pharmacol 2021; 12:717719. [PMID: 34630096 PMCID: PMC8495126 DOI: 10.3389/fphar.2021.717719] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/02/2021] [Indexed: 02/02/2023] Open
Abstract
Background: Cranial radiotherapy is clinically used in the treatment of brain tumours; however, the consequent cognitive and emotional dysfunctions seriously impair the life quality of patients. LW-AFC, an active fraction combination extracted from classical traditional Chinese medicine prescription Liuwei Dihuang decoction, can improve cognitive and emotional dysfunctions in many animal models; however, the protective effect of LW-AFC on cranial irradiation–induced cognitive and emotional dysfunctions has not been reported. Recent studies indicate that impairment of adult hippocampal neurogenesis (AHN) and alterations of the neurogenic microenvironment in the hippocampus constitute critical factors in cognitive and emotional dysfunctions following cranial irradiation. Here, our research further investigated the potential protective effects and mechanisms of LW-AFC on cranial irradiation–induced cognitive and emotional dysfunctions in mice. Methods: LW-AFC (1.6 g/kg) was intragastrically administered to mice for 14 days before cranial irradiation (7 Gy γ-ray). AHN was examined by quantifying the number of proliferative neural stem cells and immature neurons in the dorsal and ventral hippocampus. The contextual fear conditioning test, open field test, and tail suspension test were used to assess cognitive and emotional functions in mice. To detect the change of the neurogenic microenvironment, colorimetry and multiplex bead analysis were performed to measure the level of oxidative stress, neurotrophic and growth factors, and inflammation in the hippocampus. Results: LW-AFC exerted beneficial effects on the contextual fear memory, anxiety behaviour, and depression behaviour in irradiated mice. Moreover, LW-AFC increased the number of proliferative neural stem cells and immature neurons in the dorsal hippocampus, displaying a regional specificity of neurogenic response. For the neurogenic microenvironment, LW-AFC significantly increased the contents of superoxide dismutase, glutathione peroxidase, glutathione, and catalase and decreased the content of malondialdehyde in the hippocampus of irradiated mice, accompanied by the increase in brain-derived neurotrophic factor, insulin-like growth factor-1, and interleukin-4 content. Together, LW-AFC improved cognitive and emotional dysfunctions, promoted AHN preferentially in the dorsal hippocampus, and ameliorated disturbance in the neurogenic microenvironment in irradiated mice. Conclusion: LW-AFC ameliorates cranial irradiation–induced cognitive and emotional dysfunctions, and the underlying mechanisms are mediated by promoting AHN in the dorsal hippocampus and improving the neurogenic microenvironment. LW-AFC might be a promising therapeutic agent to treat cognitive and emotional dysfunctions in patients receiving cranial radiotherapy.
Collapse
Affiliation(s)
- Mingxiao Wei
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Shufang Feng
- Department of Poisoning and the Treatment, Affiliated Hospital to Academy of Military Medical Sciences (the 307 Hospital), Beijing, China
| | - Lin Zhang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Chen Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Shasha Chu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Tianyao Shi
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Wenxia Zhou
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Yongxiang Zhang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| |
Collapse
|
11
|
Levone BR, Codagnone MG, Moloney GM, Nolan YM, Cryan JF, O' Leary OF. Adult-born neurons from the dorsal, intermediate, and ventral regions of the longitudinal axis of the hippocampus exhibit differential sensitivity to glucocorticoids. Mol Psychiatry 2021; 26:3240-3252. [PMID: 32709996 DOI: 10.1038/s41380-020-0848-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 07/06/2020] [Accepted: 07/14/2020] [Indexed: 01/05/2023]
Abstract
Hippocampal neurogenesis has been shown to play roles in learning, memory, and stress responses. These diverse roles may be related to a functional segregation of the hippocampus along its longitudinal axis. Indeed, the dorsal hippocampus (dHi) plays a predominant role in spatial learning and memory, while the ventral hippocampus (vHi) is predominantly involved in the regulation of anxiety, a behaviour impacted by stress. Recent studies suggest that the area between them, the intermediate hippocampus (iHi) may also be functionally independent. In parallel, it has been reported that chronic stress reduces neurogenesis preferentially in the vHi rather the dHi. We thus aimed to determine whether such stress-induced changes in neurogenesis could be related to differential intrinsic sensitivity of neural progenitor cells (NPCs) from the dHi, iHi, or vHi to the stress hormone, corticosterone, or the glucocorticoid receptor (GR) agonist, dexamethasone. Long-term exposure of rat NPCs to corticosterone or dexamethasone decreased neuronal differentiation in the vHi but not the dHi, while iHi cultures showed an intermediate response. A similar gradient-like response on neuronal differentiation and maturation was observed with dexamethasone treatment. This gradient-like effect was also observed on GR nuclear translocation in response to corticosterone or dexamethasone. Long-term exposure to corticosterone or dexamethasone treatment also tended to induce a greater downregulation of GR-associated genes in vHi-derived neurons compared to those from the dHi and iHi. These data suggest that increased intrinsic sensitivity of vHi NPC-derived neurons to chronic glucocorticoid exposure may underlie the increased vulnerability of the vHi to chronic stress-induced reductions in neurogenesis.
Collapse
Affiliation(s)
- Brunno Rocha Levone
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Martin G Codagnone
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Gerard M Moloney
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Olivia F O' Leary
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland. .,APC Microbiome Ireland, University College Cork, Cork, Ireland.
| |
Collapse
|
12
|
Huckleberry KA, Shansky RM. The unique plasticity of hippocampal adult-born neurons: Contributing to a heterogeneous dentate. Hippocampus 2021; 31:543-556. [PMID: 33638581 DOI: 10.1002/hipo.23318] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 01/15/2021] [Accepted: 02/09/2021] [Indexed: 12/14/2022]
Abstract
The dentate gyrus (DG) of the hippocampus is evolutionarily conserved as one of the few sites of adult neurogenesis in mammals. Although there is clear evidence that neurogenesis is necessary for healthy hippocampal function, whether adult-born neurons are simply integrated into existing hippocampal networks to serve a similar purpose to that of developmentally born neurons or whether they represent a discrete cell population with unique functions remains less clear. In this review, we consider evidence for discrete cellular, synaptic, and structural features of adult-born DG neurons, suggesting that neurogenesis contributes to the formation of a heterogeneous DG. We therefore propose that hippocampal neurogenesis creates a specialized neuronal subpopulation that may play a key role in hippocampal functions like episodic memory. We note critical gaps in this extensive body of work, including a general failure to include female animals in relevant research and a need for more precise consideration of intrahippocampal neuroanatomy.
Collapse
Affiliation(s)
- Kylie A Huckleberry
- Behavioral Neuroscience Program, Department of Psychology, Northeastern University, Boston, Massachusetts, USA
| | - Rebecca M Shansky
- Behavioral Neuroscience Program, Department of Psychology, Northeastern University, Boston, Massachusetts, USA
| |
Collapse
|
13
|
VEGF/VEGFR-2 system exerts neuroprotection against Phoneutria nigriventer spider envenomation through PI3K-AKT-dependent pathway. Toxicon 2020; 185:76-90. [PMID: 32649934 DOI: 10.1016/j.toxicon.2020.06.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 06/23/2020] [Accepted: 06/23/2020] [Indexed: 01/19/2023]
Abstract
This study was undertaken to elucidate why VEGF/VEGFR-2 is elevated in the hippocampus of rats injected with Phoneutria nigriventer spider venom (PNV). PNV delays Na+ channels inactivation; blocks Ca2+ and K+ channels, increases glutamate release, causes blood-brain breakdown (BBBb), brain edema and severe excitotoxicity. Analytical FT-IR spectroscopy showed profound alteration in molecular biochemical state, with evidences for VEGFR-2 (KDR/Flk-1) signaling mediation. By blocking VEGF/VEGFR-2 binding via pre-treatment with itraconazole we demonstrated that animals' condition was deteriorated soon at 1-2 h post-PNV exposure concurrently with decreased expression of VEGF, BBB-associated proteins, ZO-1, β-catenin, laminin, P-gp (P-glycoprotein), Neu-N (neuron's viability marker) and MAPKphosphorylated-p38, while phosphorylated-ERK and Src pathways were increased. At 5 h and coinciding with incipient signs of animals' recuperation, the proteins associated with protection (HIF-1α, VEGF, VEGFR-1, VEGFR-2, Neu-N, occludin, β-catenin, laminin, P-gp efflux protein, phosphorylated-p38) increased thus indicating p38 pathway activation together with paracellular route strengthening. However, the BBB transcellular trafficking and caspase-3 increased (pro-apoptotic pathway activation). At 24 h, the transcellular route reestablished physiological state but the pro-survival pathway PI3K/(p-Akt) dropped in animals underwent VEGF/VEGFR-2 binding inhibition, whereas it was significantly activated at matched interval in PNV group without prior itraconazole; these results demonstrate impaired VEGF' survival effects at 24 h. The inhibition of VEGF/VEGFR-2 binding identified 5 h as turning point at which multi-level dynamic interplay was elicited to reverse hippocampal damage. Collectively, the data confirmed VEGFR-2 signaling via serine-threonine kinase Akt as neuroprotective pathway against PNV-induced damage. Further studies are needed to elucidate mechanisms underlying PNV effects.
Collapse
|
14
|
Andermane N, Joensen BH, Horner AJ. Forgetting across a hierarchy of episodic representations. Curr Opin Neurobiol 2020; 67:50-57. [PMID: 32882596 DOI: 10.1016/j.conb.2020.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/03/2020] [Accepted: 08/05/2020] [Indexed: 11/29/2022]
Abstract
Rich episodic experiences are represented in a hierarchical manner across a diverse network of brain regions, and as such, the way in which episodes are forgotten is likely to be similarly diverse. Using novel experimental approaches and statistical modelling, recent research has suggested that item-based representations, such as ones related to the colour and shape of an object, fragment over time, whereas higher-order event-based representations may be forgotten in a more 'holistic' uniform manner. We propose a framework that reconciles these findings, where complex episodes are represented in a hierarchical manner, from individual items, to small-scale events, to large-scale episodic narratives. Each level in the hierarchy is represented in distinct brain regions, from the perirhinal cortex, to posterior hippocampus, to anterior hippocampus and ventromedial prefrontal cortex. Critically, forgetting may be underpinned by different mechanisms at each level in the hierarchy, leading to different patterns of behaviour.
Collapse
Affiliation(s)
| | - Bárður H Joensen
- Institute of Cognitive Neuroscience, UCL, London, UK; Institute of Neurology, UCL, London, UK
| | - Aidan J Horner
- Department of Psychology, University of York, York, UK; York Biomedical Research Institute, University of York, York, UK.
| |
Collapse
|
15
|
Sex Differences in Maturation and Attrition of Adult Neurogenesis in the Hippocampus. eNeuro 2020; 7:ENEURO.0468-19.2020. [PMID: 32586842 PMCID: PMC7369314 DOI: 10.1523/eneuro.0468-19.2020] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 12/13/2022] Open
Abstract
Sex differences exist in the regulation of adult neurogenesis in the hippocampus in response to hormones and cognitive training. Here, we investigated the trajectory and maturation rate of adult-born neurons in the dentate gyrus (DG) of male and female rats. Sprague Dawley rats were perfused 2 h, 24 h, one week (1w), 2w, or 3w after bromodeoxyuridine (BrdU) injection, a DNA synthesis marker that labels dividing progenitor cells and their progeny. Adult-born neurons (BrdU/NeuN-ir) matured faster in males compared with females. Males had a greater density of neural stem cells (Sox2-ir) in the dorsal, but not in the ventral, DG and had higher levels of cell proliferation (Ki67-ir) than non-proestrous females. However, males showed a greater reduction in neurogenesis between 1week and 2weeks after mitosis, whereas females showed similar levels of neurogenesis throughout the weeks. The faster maturation and greater attrition of new neurons in males compared with females suggests greater potential for neurogenesis to respond to external stimuli in males and emphasizes the importance of studying sex on adult hippocampal neurogenesis.
Collapse
|
16
|
Connolly MG, Yost OL, Potter OV, Giedraitis ME, Kohman RA. Toll-like receptor 4 differentially regulates adult hippocampal neurogenesis in an age- and sex-dependent manner. Hippocampus 2020; 30:958-969. [PMID: 32343455 DOI: 10.1002/hipo.23209] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 04/07/2020] [Accepted: 04/09/2020] [Indexed: 12/15/2022]
Abstract
Toll-like receptor 4 (TLR4) is primarily responsible for initiating an immune response following pathogen recognition. However, TLR4 is also expressed on neural progenitor cells and has been reported to regulate hippocampal neurogenesis as young male TLR4 knockout mice show increases in cell proliferation and doublecortin positive cells. Whether these effects occur in both sexes and are sustained with normal aging is currently unknown. The present study evaluated whether TLR4 deficiency alters adult hippocampal neurogenesis in young (3-4 months) and aged (18-20 months), male and female, TLR4 deficient (TLR4-/-; B6.B10ScN-Tlr4lps-del/JthJ) and wild type (WT) mice. Additionally, neurogenesis within the dorsal and the ventral hippocampal subdivisions was evaluated to determine if TLR4 has differential effects across the hippocampus. Bromodeoxyuridine (BrdU) was administered to quantify new cell survival as well as cell differentiation. Ki-67 was measured to evaluate cell proliferation. Results show that young TLR4-/- females had higher rates of proliferation and neuronal differentiation in both the dorsal and ventral hippocampus relative to WT females. Young TLR4-/- males show elevated proliferation and neuronal differentiation mainly in the ventral hippocampus. While young TLR4-/- mice show enhanced neurogenesis compared to young WT mice, the increase was not apparent in the aged TLR4-/- mice. Both aged WT and TLR4-/- mice showed a decrease in proliferation, new cell survival, and neuronal differentiation compared to young WT and TLR4-/- mice. The data collectively indicate that TLR4 regulates hippocampal neurogenesis in young adults, but that these effects are region-specific in males and that females show broader changes in neurogenesis throughout the hippocampus.
Collapse
Affiliation(s)
- Meghan G Connolly
- Department of Psychology, University of North Carolina Wilmington, Wilmington, North Carolina, USA
| | - Oriana L Yost
- Department of Psychology, University of North Carolina Wilmington, Wilmington, North Carolina, USA
| | - Opal V Potter
- School of Medicine, Wake Forest University, Winston Salem, North Carolina, USA
| | - Megan E Giedraitis
- Department of Psychology, University of North Carolina Wilmington, Wilmington, North Carolina, USA
| | - Rachel A Kohman
- Department of Psychology, University of North Carolina Wilmington, Wilmington, North Carolina, USA
| |
Collapse
|
17
|
Lucassen PJ, Fitzsimons CP, Salta E, Maletic-Savatic M. Adult neurogenesis, human after all (again): Classic, optimized, and future approaches. Behav Brain Res 2020; 381:112458. [DOI: 10.1016/j.bbr.2019.112458] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 11/29/2019] [Accepted: 12/28/2019] [Indexed: 02/08/2023]
|
18
|
Suppressed neurogenesis without cognitive deficits: effects of fast neutron irradiation in mice. Neuroreport 2019; 30:538-543. [PMID: 30950935 DOI: 10.1097/wnr.0000000000001237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
This study assessed the effects of combined low-dose neutron and γ-ray irradiation on hippocampal neurogenesis and hippocampal-dependent memory. Neural progenitor cell division and survival were evaluated in brain sections and whole hippocampal preparations following head irradiation at a dose of 0.34 Gy for neutron radiation and 0.36 Gy for γ-ray radiation. Hippocampal-dependent memory formation was tested in a contextual fear conditioning task following irradiation at doses of 0.4 Gy for neutron radiation and 0.42 Gy for γ-ray radiation. Cell division was suppressed consistently along the entire dorsoventral axis of the hippocampus 24 h after the irradiation, but quiescent stem cells remained unaffected. The control and irradiated mice showed no differences in terms of exploratory behavior or anxiety 6 weeks after the irradiation. The ability to form hippocampus-dependent memory was also unaffected. The data may be indicative of a negligible effect of the low-dose of fast neutron irradiation and the neurogenesis suppression on animal behavior at 6 weeks after irradiation.
Collapse
|
19
|
Bekiari C, Grivas I, Tsingotjidou A, Papadopoulos GC. Adult neurogenesis and gliogenesis in the dorsal and ventral canine hippocampus. J Comp Neurol 2019; 528:1216-1230. [PMID: 31743444 DOI: 10.1002/cne.24818] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 11/08/2019] [Accepted: 11/08/2019] [Indexed: 12/13/2022]
Abstract
Dentate gyrus (DG) of the mammalian hippocampus gives rise to new neurons and astrocytes all through adulthood. Canine hippocampus presents many similarities in fetal development, anatomy, and physiology with human hippocampus, establishing canines as excellent animal models for the study of adult neurogenesis. In the present study, BrdU-dated cells of the structurally and functionally dissociated dorsal (dDG) and ventral (vDG) adult canine DG were comparatively examined over a period of 30 days. Each part's neurogenic potential, radial glia-like neural stem cells (NSCs) proliferation and differentiation, migration, and maturation of their progenies were evaluated at 2, 5, 14, and 30 days post BrdU administration, with the use of selected markers (glial fibrillary acidic protein, doublecortin, calretinin and calbindin). Co-staining of BrdU+ cells with NeuN or S100B permitted the parallel study of the ongoing neurogenesis and gliogenesis. Our findings reveal the comparatively higher populations of residing granule cells, proliferating NSCs and BrdU+ neurons in the dDG, whereas newborn neurons of the vDG showed a prolonged differentiation, migration, and maturation. Newborn astrocytes were found all along the dorso-ventral axis, counting however for only 11% of newborn cell population. Comparative evaluation of adult canine and rat neurogenesis revealed significant differences in the distribution of resident and newborn granule cells along the dorso-ventral axis, division pattern of adult NSCs, maturation time plan of newborn neurons, and ongoing gliogenesis. Concluding, spatial and temporal features of adult canine neurogenesis are similar to that of other gyrencephalic species, including humans, and justify the comparative examination of adult neurogenesis across mammalian species.
Collapse
Affiliation(s)
- Chryssa Bekiari
- Laboratory of Anatomy, Histology & Embryology, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Ioannis Grivas
- Laboratory of Anatomy, Histology & Embryology, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Anastasia Tsingotjidou
- Laboratory of Anatomy, Histology & Embryology, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Georgios C Papadopoulos
- Laboratory of Anatomy, Histology & Embryology, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| |
Collapse
|
20
|
Kedrov AV, Mineyeva OA, Enikolopov GN, Anokhin KV. Involvement of Adult-born and Preexisting Olfactory Bulb and Dentate Gyrus Neurons in Single-trial Olfactory Memory Acquisition and Retrieval. Neuroscience 2019; 422:75-87. [DOI: 10.1016/j.neuroscience.2019.09.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 08/24/2019] [Accepted: 09/10/2019] [Indexed: 12/12/2022]
|
21
|
Gualtieri F, Armstrong EA, Longmoor GK, D'Eath RB, Sandilands V, Boswell T, Smulders TV. Unpredictable Chronic Mild Stress Suppresses the Incorporation of New Neurons at the Caudal Pole of the Chicken Hippocampal Formation. Sci Rep 2019; 9:7129. [PMID: 31073135 PMCID: PMC6509118 DOI: 10.1038/s41598-019-43584-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 04/25/2019] [Indexed: 02/08/2023] Open
Abstract
In the mammalian brain, adult hippocampal neurogenesis (AHN) is suppressed by chronic stress, primarily at the ventral pole of the hippocampus. Based upon anatomy, we hypothesise that the caudal pole of the avian Hippocampal Formation (HF) presents a homologous subregion. We thus investigated whether AHN is preferentially suppressed in the caudal chicken HF by unpredictable chronic mild stress (UCMS). Adult hens were kept in control conditions or exposed to UCMS for 8 weeks. Hens experiencing UCMS had significantly fewer doublecortin-positive multipolar neurons (p < 0.001) and beaded axons (p = 0.021) at the caudal pole of the HF than controls. UCMS birds also had smaller spleens and lower baseline plasma corticosterone levels compared to controls. There were no differences in AHN at the rostral pole, nor were there differences in expression of genetic mediators of the HPA stress response in the pituitary or adrenal glands. Duration of tonic immobility and heterophil/lymphocyte (H/L) ratios were also not responsive to our UCMS treatment. These results support the hypothesised homology of the caudal pole of the avian HF to the ventral pole of the rodent hippocampus. Furthermore, quantifying neurogenesis in the caudal HF post-mortem may provide an objective, integrative measure of welfare in poultry, which may be more sensitive than current welfare measures.
Collapse
Affiliation(s)
- F Gualtieri
- Centre for Behaviour & Evolution, Newcastle University, Newcastle upon Tyne, UK.,Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - E A Armstrong
- Centre for Behaviour & Evolution, Newcastle University, Newcastle upon Tyne, UK.,Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - G K Longmoor
- Centre for Behaviour & Evolution, Newcastle University, Newcastle upon Tyne, UK.,Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - R B D'Eath
- Animal and Veterinary Science Research Group, SRUC, Edinburgh, UK
| | - V Sandilands
- Animal and Veterinary Science Research Group, SRUC, Edinburgh, UK
| | - T Boswell
- Centre for Behaviour & Evolution, Newcastle University, Newcastle upon Tyne, UK.,School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - T V Smulders
- Centre for Behaviour & Evolution, Newcastle University, Newcastle upon Tyne, UK. .,Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.
| |
Collapse
|
22
|
Pregnancy Promotes Maternal Hippocampal Neurogenesis in Guinea Pigs. Neural Plast 2019; 2019:5765284. [PMID: 31097956 PMCID: PMC6487096 DOI: 10.1155/2019/5765284] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/08/2019] [Accepted: 02/21/2019] [Indexed: 11/26/2022] Open
Abstract
Adult neurogenesis in the hippocampal dentate gyrus (DG) modulates cognition and behavior in mammals, while motherhood is associated with cognitive and behavioral changes essential for the care of the young. In mice and rats, hippocampal neurogenesis is reported to be reduced or unchanged during pregnancy, with few data available from other species. In guinea pigs, pregnancy lasts ~9 weeks; we set to explore if hippocampal neurogenesis is altered in these animals, relative to gestational stages. Time-pregnant primigravidas (3-5 months old) and age-matched nonpregnant females were examined, with neurogenic potential evaluated via immunolabeling of Ki67, Sp8, doublecortin (DCX), and neuron-specific nuclear antigen (NeuN) combined with bromodeoxyuridine (BrdU) birth-dating. Relative to control, subgranular Ki67, Sp8, and DCX-immunoreactive (+) cells tended to increase from early gestation to postpartum and peaked at the late gestational stage. In BrdU pulse-chasing experiments in nonpregnant females surviving for different time points (2-120 days), BrdU+ cells in the DG colocalized with DCX partially from 2 to 42 days (most frequently at 14-30 days) and with NeuN increasingly from 14 to 120 days. In pregnant females that received BrdU at early, middle, and late gestational stages and survived for 42 days, the density of BrdU+ cells in the DG was mostly high in the late gestational group. The rates of BrdU/DCX and BrdU/NeuN colocalization were similar among these groups and comparable to those among the corresponding control group. Together, the findings suggest that pregnancy promotes maternal hippocampal neurogenesis in guinea pigs, at least among primigravidas.
Collapse
|
23
|
Huckleberry KA, Shue F, Copeland T, Chitwood RA, Yin W, Drew MR. Dorsal and ventral hippocampal adult-born neurons contribute to context fear memory. Neuropsychopharmacology 2018; 43:2487-2496. [PMID: 29941977 PMCID: PMC6180107 DOI: 10.1038/s41386-018-0109-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/06/2018] [Accepted: 05/29/2018] [Indexed: 12/16/2022]
Abstract
The hippocampus contains one of the few neurogenic niches within the adult brain-the subgranular zone of the dentate gyrus. The functional significance of adult-born neurons in this region has been characterized using context fear conditioning, a Pavlovian paradigm in which animals learn to associate a location with danger. Ablation or silencing of adult-born neurons impairs both acquisition and recall of contextual fear conditioning, suggesting that these neurons contribute importantly to hippocampal memory. Lesion studies indicate that CFC depends on neural activity in both the dorsal and ventral hippocampus, subregions with unique extrahippocampal connectivity and behavioral functions. Because most studies of adult neurogenesis have relied on methods that permanently ablate neurogenesis throughout the entire hippocampus, little is known about how the function of adult-born neurons varies along the dorsal-ventral axis. Using a Nestin-CreERT2 mouse line to target the optogenetic silencer Archaerhodopsin to adult-born neurons, we compared the contribution of dorsal and ventral adult-born neurons to acquisition, recall, and generalization of CFC. Acquisition of CFC was impaired when either dorsal or ventral adult-born neurons were silenced during training. Silencing dorsal or ventral adult-born neurons during test sessions decreased context-evoked freezing but did not impair freezing in a hippocampus-independent tone-shock freezing paradigm. Silencing adult-born neurons modestly reduced generalization of fear. Our data indicate that adult-born neurons in the dorsal and ventral hippocampus contribute to both memory acquisition and recall. The comparatively large behavioral effects of silencing a small number of adult-born neurons suggest that these neurons make a unique and powerful contribution to hippocampal function.
Collapse
Affiliation(s)
- Kylie A. Huckleberry
- 0000 0004 1936 9924grid.89336.37Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX USA
| | - Francis Shue
- 0000 0004 1936 9924grid.89336.37Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX USA
| | - Taylor Copeland
- 0000 0004 1936 9924grid.89336.37Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX USA
| | - Raymond A. Chitwood
- 0000 0004 1936 9924grid.89336.37Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX USA
| | - Weiling Yin
- 0000 0004 1936 9924grid.89336.37Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX USA
| | - Michael R. Drew
- 0000 0004 1936 9924grid.89336.37Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX USA
| |
Collapse
|
24
|
Whole-Body 12C Irradiation Transiently Decreases Mouse Hippocampal Dentate Gyrus Proliferation and Immature Neuron Number, but Does Not Change New Neuron Survival Rate. Int J Mol Sci 2018; 19:ijms19103078. [PMID: 30304778 PMCID: PMC6213859 DOI: 10.3390/ijms19103078] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/17/2018] [Accepted: 09/21/2018] [Indexed: 02/08/2023] Open
Abstract
High-charge and -energy (HZE) particles comprise space radiation and they pose a challenge to astronauts on deep space missions. While exposure to most HZE particles decreases neurogenesis in the hippocampus—a brain structure important in memory—prior work suggests that 12C does not. However, much about 12C’s influence on neurogenesis remains unknown, including the time course of its impact on neurogenesis. To address this knowledge gap, male mice (9–11 weeks of age) were exposed to whole-body 12C irradiation 100 cGy (IRR; 1000 MeV/n; 8 kEV/µm) or Sham treatment. To birthdate dividing cells, mice received BrdU i.p. 22 h post-irradiation and brains were harvested 2 h (Short-Term) or three months (Long-Term) later for stereological analysis indices of dentate gyrus neurogenesis. For the Short-Term time point, IRR mice had fewer Ki67, BrdU, and doublecortin (DCX) immunoreactive (+) cells versus Sham mice, indicating decreased proliferation (Ki67, BrdU) and immature neurons (DCX). For the Long-Term time point, IRR and Sham mice had similar Ki67+ and DCX+ cell numbers, suggesting restoration of proliferation and immature neurons 3 months post-12C irradiation. IRR mice had fewer surviving BrdU+ cells versus Sham mice, suggesting decreased cell survival, but there was no difference in BrdU+ cell survival rate when compared within treatment and across time point. These data underscore the ability of neurogenesis in the mouse brain to recover from the detrimental effect of 12C exposure.
Collapse
|
25
|
Stefani J, Tschesnokowa O, Parrilla M, Robaye B, Boeynaems JM, Acker-Palmer A, Zimmermann H, Gampe K. Disruption of the Microglial ADP Receptor P2Y 13 Enhances Adult Hippocampal Neurogenesis. Front Cell Neurosci 2018; 12:134. [PMID: 29867367 PMCID: PMC5966569 DOI: 10.3389/fncel.2018.00134] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 04/30/2018] [Indexed: 12/20/2022] Open
Abstract
In mammalian species, including humans, the hippocampal dentate gyrus (DG) is a primary region of adult neurogenesis. Aberrant adult hippocampal neurogenesis is associated with neurological pathologies. Understanding the cellular mechanisms controlling adult hippocampal neurogenesis is expected to open new therapeutic strategies for mental disorders. Microglia is intimately associated with neural progenitor cells in the hippocampal DG and has been implicated, under varying experimental conditions, in the control of the proliferation, differentiation and survival of neural precursor cells. But the underlying mechanisms remain poorly defined. Using fluorescent in situ hybridization we show that microglia in brain express the ADP-activated P2Y13 receptor under basal conditions and that P2ry13 mRNA is absent from neurons, astrocytes, and neural progenitor cells. Disrupting P2ry13 decreases structural complexity of microglia in the hippocampal subgranular zone (SGZ). But it increases progenitor cell proliferation and new neuron formation. Our data suggest that P2Y13 receptor-activated microglia constitutively attenuate hippocampal neurogenesis. This identifies a signaling pathway whereby microglia, via a nucleotide-mediated mechanism, contribute to the homeostatic control of adult hippocampal neurogenesis. Selective P2Y13R antagonists could boost neurogenesis in pathological conditions associated with impaired hippocampal neurogenesis.
Collapse
Affiliation(s)
- Jennifer Stefani
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt am Main, Germany
| | - Olga Tschesnokowa
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt am Main, Germany
| | - Marta Parrilla
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt am Main, Germany.,Max-Planck-Institute for Brain Research, Frankfurt am Main, Germany
| | - Bernard Robaye
- Institute of Interdisciplinary Research, School of Medicine, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Jean-Marie Boeynaems
- Institute of Interdisciplinary Research, School of Medicine, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Amparo Acker-Palmer
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt am Main, Germany.,Max-Planck-Institute for Brain Research, Frankfurt am Main, Germany.,Focus Program Translational Neurosciences (FTN), University of Mainz, Mainz, Germany
| | - Herbert Zimmermann
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt am Main, Germany
| | - Kristine Gampe
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt am Main, Germany
| |
Collapse
|
26
|
Spatial geometry of stem cell proliferation in the adult hippocampus. Sci Rep 2018; 8:3444. [PMID: 29467395 PMCID: PMC5821870 DOI: 10.1038/s41598-018-21078-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 01/29/2018] [Indexed: 01/16/2023] Open
Abstract
The modes of stem cell divisions (e.g., symmetric vs. asymmetric) can have a profound impact on the number of progeny and tissue growth, repair, and function. This is particularly relevant for adult neural stem cells, since stem cell-derived neurons affect cognitive and mental states, resistance to stress and disease, and response to therapies. Here we show that although dividing stem cells in the adult hippocampus display a certain bias towards paired distribution (which could imply the prevalence of symmetric divisions), this bias already exists in the distribution of the general population of stem cells and may be responsible for the perceived occurrence of symmetric stem cell divisions. Remarkably, the bias in the distribution of stem cells decreases with age. Our results argue that the preexisting bias in stem cell distribution may affect current assumptions regarding stem cell division and fate as well as conjectures on the prospects of brain repair and rejuvenation.
Collapse
|
27
|
Wiget F, van Dijk RM, Louet ER, Slomianka L, Amrein I. Effects of Strain and Species on the Septo-Temporal Distribution of Adult Neurogenesis in Rodents. Front Neurosci 2017; 11:719. [PMID: 29311796 PMCID: PMC5742116 DOI: 10.3389/fnins.2017.00719] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 12/08/2017] [Indexed: 01/05/2023] Open
Abstract
The functional septo-temporal (dorso-ventral) differentiation of the hippocampus is accompanied by gradients of adult hippocampal neurogenesis (AHN) in laboratory rodents. An extensive septal AHN in laboratory mice suggests an emphasis on a relation of AHN to tasks that also depend on the septal hippocampus. Domestication experiments indicate that AHN dynamics along the longitudinal axis are subject to selective pressure, questioning if the septal emphasis of AHN in laboratory mice is a rule applying to rodents in general. In this study, we used C57BL/6 and DBA2/Crl mice, wild-derived F1 house mice and wild-captured wood mice and bank voles to look for evidence of strain and species specific septo-temporal differences in AHN. We confirmed the septal > temporal gradient in C57BL/6 mice, but in the wild species, AHN was low septally and high temporally. Emphasis on the temporal hippocampus was particularly strong for doublecortin positive (DCX+) young neurons and more pronounced in bank voles than in wood mice. The temporal shift was stronger in female wood mice than in males, while we did not see sex differences in bank voles. AHN was overall low in DBA and F1 house mice, but they exhibited the same inversed gradient as wood mice and bank voles. DCX+ young neurons were usually confined to the subgranular zone and deep granule cell layer. This pattern was seen in all animals in the septal and intermediate dentate gyrus. In bank voles and wood mice however, the majority of temporal DCX+ cells were radially dispersed throughout the granule cell layer. Some but not all of the septo-temporal differences were accompanied by changes in the DCX+/Ki67+ cell ratios, suggesting that new neuron numbers can be regulated by both proliferation or the time course of maturation and survival of young neurons. Some of the septo-temporal differences we observe have also been found in laboratory rodents after the experimental manipulation of the molecular mechanisms that control AHN. Adaptations of AHN under natural conditions may operate on these or similar mechanisms, adjusting neurogenesis to the requirements of hippocampal function.
Collapse
Affiliation(s)
- Franziska Wiget
- Division of Functional Neuroanatomy, Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - R Maarten van Dijk
- Division of Functional Neuroanatomy, Institute of Anatomy, University of Zurich, Zurich, Switzerland.,Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilian-University, Munich, Germany
| | - Estelle R Louet
- Division of Functional Neuroanatomy, Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Lutz Slomianka
- Division of Functional Neuroanatomy, Institute of Anatomy, University of Zurich, Zurich, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Irmgard Amrein
- Division of Functional Neuroanatomy, Institute of Anatomy, University of Zurich, Zurich, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| |
Collapse
|
28
|
Magagna-Poveda A, Moretto JN, Scharfman HE. Increased gyrification and aberrant adult neurogenesis of the dentate gyrus in adult rats. Brain Struct Funct 2017; 222:4219-4237. [PMID: 28656372 PMCID: PMC5909844 DOI: 10.1007/s00429-017-1457-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Accepted: 06/06/2017] [Indexed: 02/08/2023]
Abstract
A remarkable example of maladaptive plasticity is the development of epilepsy after a brain insult or injury to a normal animal or human. A structure that is considered central to the development of this type of epilepsy is the dentate gyrus (DG), because it is normally a relatively inhibited structure and its quiescence is thought to reduce hippocampal seizure activity. This characteristic of the DG is also considered to be important for normal hippocampal-dependent cognitive functions. It has been suggested that the brain insults which cause epilepsy do so because they cause the DG to be more easily activated. One type of brain insult that is commonly used is induction of severe seizures (status epilepticus; SE) by systemic injection of a convulsant drug. Here we describe an alteration in the DG after this type of experimental SE that may contribute to chronic seizures that has not been described before: large folds or gyri that develop in the DG by 1 month after SE. Large gyri appeared to increase network excitability because epileptiform discharges recorded in hippocampal slices after SE were longer in duration when recorded inside gyri relative to locations outside gyri. Large gyri may also increase excitability because immature adult-born neurons accumulated at the base of gyri with time after SE, and previous studies have suggested that abnormalities in adult-born DG neurons promote seizures after SE. In summary, large gyri after SE are a common finding in adult rats, show increased excitability, and are associated with the development of an abnormal spatial distribution of adult-born neurons. Together these alterations may contribute to chronic seizures and associated cognitive comorbidities after SE.
Collapse
Affiliation(s)
- Alejandra Magagna-Poveda
- The Nathan Kline Institute of Psychiatric Research, Center for Dementia Research, 140 Old Orangeburg Rd. Bldg. 35, Orangeburg, NY, 10962, USA
| | - Jillian N Moretto
- The Nathan Kline Institute of Psychiatric Research, Center for Dementia Research, 140 Old Orangeburg Rd. Bldg. 35, Orangeburg, NY, 10962, USA
| | - Helen E Scharfman
- The Nathan Kline Institute of Psychiatric Research, Center for Dementia Research, 140 Old Orangeburg Rd. Bldg. 35, Orangeburg, NY, 10962, USA.
- Department of Child and Adolescent Psychiatry, New York University Langone Medical Center, One Park Ave., New York, NY, 10016, USA.
- Department of Physiology and Neuroscience, New York University Langone Medical Center, One Park Ave., New York, NY, 10016, USA.
- Department of Psychiatry, New York University Langone Medical Center, One Park Ave., New York, NY, 10016, USA.
| |
Collapse
|
29
|
Amorim RP, Araújo MGL, Valero J, Lopes-Cendes I, Pascoal VDB, Malva JO, da Silva Fernandes MJ. Silencing of P2X7R by RNA interference in the hippocampus can attenuate morphological and behavioral impact of pilocarpine-induced epilepsy. Purinergic Signal 2017; 13:467-478. [PMID: 28707031 PMCID: PMC5714836 DOI: 10.1007/s11302-017-9573-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 06/28/2017] [Indexed: 12/01/2022] Open
Abstract
Cell signaling mediated by P2X7 receptors (P2X7R) has been suggested to be involved in epileptogenesis, via modulation of intracellular calcium levels, excitotoxicity, activation of inflammatory cascades, and cell death, among other mechanisms. These processes have been described to be involved in pilocarpine-induced status epilepticus (SE) and contribute to hyperexcitability, resulting in spontaneous and recurrent seizures. Here, we aimed to investigate the role of P2X7R in epileptogenesis in vivo using RNA interference (RNAi) to inhibit the expression of this receptor. Small interfering RNA (siRNA) targeting P2X7R mRNA was injected into the lateral ventricles (icv) 6 h after SE. Four groups were studied: Saline-Vehicle, Saline-siRNA, Pilo-Vehicle, and Pilo-siRNA. P2X7R was quantified by western blotting and neuronal death assessed by Fluoro-Jade B histochemistry. The hippocampal volume (edema) was determined 48 h following RNAi. Behavioral parameters as latency to the appearance of spontaneous seizures and the number of seizures were determined until 60 days after the SE onset. The Saline-siRNA and Pilo-siRNA groups showed a 43 and 37% reduction, respectively, in P2X7R protein levels compared to respective vehicle groups. Neuroprotection was observed in CA1 and CA3 of the Pilo-siRNA group compared to Pilo-Vehicle. P2X7R silencing in pilocarpine group reversed the increase in the edema detected in the hilus, suprapyramidal dentate gyrus, CA1, and CA3; reduced mortality rate following SE; increased the time to onset of spontaneous seizure; and reduced the number of seizures, when compared to the Pilo-Vehicle group. Therefore, our data highlights the potential of P2X7R as a therapeutic target for the adjunct treatment of epilepsy.
Collapse
Affiliation(s)
- Rebeca Padrão Amorim
- Departamento de Neurologia e Neurocirurgia, Disciplina de Neurociência, Universidade Federal de São Paulo, Rua Pedro de Toledo 669, 2° andar, São Paulo, SP, CEP 04039-032, Brazil
| | - Michelle Gasparetti Leão Araújo
- Departamento de Neurologia e Neurocirurgia, Disciplina de Neurociência, Universidade Federal de São Paulo, Rua Pedro de Toledo 669, 2° andar, São Paulo, SP, CEP 04039-032, Brazil
| | - Jorge Valero
- Centro de Neurociências e Biologia Celular, Universidade de Coimbra, Coimbra, Portugal
- Achucarro Basque Center for Neuroscience, Zamudio, Bizkaia, Spain
- Ikerbasque Basque Foundation for Science, Bilbao, Bizkaia, Spain
| | - Iscia Lopes-Cendes
- Departamento de Genética Médica, Faculdade de Medicina da Unicamp, Campinas, SP, Brazil
| | | | - João Oliveira Malva
- Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Maria José da Silva Fernandes
- Departamento de Neurologia e Neurocirurgia, Disciplina de Neurociência, Universidade Federal de São Paulo, Rua Pedro de Toledo 669, 2° andar, São Paulo, SP, CEP 04039-032, Brazil.
| |
Collapse
|
30
|
Beining M, Mongiat LA, Schwarzacher SW, Cuntz H, Jedlicka P. T2N as a new tool for robust electrophysiological modeling demonstrated for mature and adult-born dentate granule cells. eLife 2017; 6:e26517. [PMID: 29165247 PMCID: PMC5737656 DOI: 10.7554/elife.26517] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 11/21/2017] [Indexed: 12/18/2022] Open
Abstract
Compartmental models are the theoretical tool of choice for understanding single neuron computations. However, many models are incomplete, built ad hoc and require tuning for each novel condition rendering them of limited usability. Here, we present T2N, a powerful interface to control NEURON with Matlab and TREES toolbox, which supports generating models stable over a broad range of reconstructed and synthetic morphologies. We illustrate this for a novel, highly detailed active model of dentate granule cells (GCs) replicating a wide palette of experiments from various labs. By implementing known differences in ion channel composition and morphology, our model reproduces data from mouse or rat, mature or adult-born GCs as well as pharmacological interventions and epileptic conditions. This work sets a new benchmark for detailed compartmental modeling. T2N is suitable for creating robust models useful for large-scale networks that could lead to novel predictions. We discuss possible T2N application in degeneracy studies.
Collapse
Affiliation(s)
- Marcel Beining
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck SocietyFrankfurtGermany
- Frankfurt Institute for Advanced StudiesFrankfurtGermany
- Institute of Clinical Neuroanatomy, Neuroscience CenterGoethe UniversityFrankfurtGermany
- Faculty of BiosciencesGoethe UniversityFrankfurtGermany
| | - Lucas Alberto Mongiat
- Instituto de Investigación en Biodiversidad y MedioambienteUniversidad Nacional del Comahue-CONICETSan Carlos de BarilocheArgentina
| | | | - Hermann Cuntz
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck SocietyFrankfurtGermany
- Frankfurt Institute for Advanced StudiesFrankfurtGermany
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Neuroscience CenterGoethe UniversityFrankfurtGermany
| |
Collapse
|
31
|
Whoolery CW, Walker AK, Richardson DR, Lucero MJ, Reynolds RP, Beddow DH, Clark KL, Shih HY, LeBlanc JA, Cole MG, Amaral WZ, Mukherjee S, Zhang S, Ahn F, Bulin SE, DeCarolis NA, Rivera PD, Chen BPC, Yun S, Eisch AJ. Whole-Body Exposure to 28Si-Radiation Dose-Dependently Disrupts Dentate Gyrus Neurogenesis and Proliferation in the Short Term and New Neuron Survival and Contextual Fear Conditioning in the Long Term. Radiat Res 2017; 188:532-551. [PMID: 28945526 PMCID: PMC5901735 DOI: 10.1667/rr14797.1] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Astronauts traveling to Mars will be exposed to chronic low doses of galactic cosmic space radiation, which contains highly charged, high-energy (HZE) particles. 56Fe-HZE-particle exposure decreases hippocampal dentate gyrus (DG) neurogenesis and disrupts hippocampal function in young adult rodents, raising the possibility of impaired astronaut cognition and risk of mission failure. However, far less is known about how exposure to other HZE particles, such as 28Si, influences hippocampal neurogenesis and function. To compare the influence of 28Si exposure on indices of neurogenesis and hippocampal function with previous studies on 56Fe exposure, 9-week-old C57BL/6J and Nestin-GFP mice (NGFP; made and maintained for 10 or more generations on a C57BL/6J background) received whole-body 28Si-particle-radiation exposure (0, 0.2 and 1 Gy, 300 MeV/n, LET 67 KeV/μ, dose rate 1 Gy/min). For neurogenesis assessment, the NGFP mice were injected with the mitotic marker BrdU at 22 h postirradiation and brains were examined for indices of hippocampal proliferation and neurogenesis, including Ki67+, BrdU+, BrdU+NeuN+ and DCX+ cell numbers at short- and long-term time points (24 h and 3 months postirradiation, respectively). In the short-term group, stereology revealed fewer Ki67+, BrdU+ and DCX+ cells in 1-Gy-irradiated group relative to nonirradiated control mice, fewer Ki67+ and DCX+ cells in 0.2 Gy group relative to control group and fewer BrdU+ and DCX+ cells in 1 Gy group relative to 0.2 Gy group. In contrast to the clearly observed radiation-induced, dose-dependent reductions in the short-term group across all markers, only a few neurogenesis indices were changed in the long-term irradiated groups. Notably, there were fewer surviving BrdU+ cells in the 1 Gy group relative to 0- and 0.2-Gy-irradiated mice in the long-term group. When the short- and long-term groups were analyzed by sex, exposure to radiation had a similar effect on neurogenesis indices in male and female mice, although only male mice showed fewer surviving BrdU+ cells in the long-term group. Fluorescent immunolabeling and confocal phenotypic analysis revealed that most surviving BrdU+ cells in the long-term group expressed the neuronal marker NeuN, definitively confirming that exposure to 1 Gy 28Si radiation decreased the number of surviving adult-generated neurons in male mice relative to both 0- and 0.2-Gy-irradiated mice. For hippocampal function assessment, 9-week-old male C57BL/6J mice received whole-body 28Si-particle exposure and were then assessed long-term for performance on contextual and cued fear conditioning. In the context test the animals that received 0.2 Gy froze less relative to control animals, suggesting decreased hippocampal-dependent function. However, in the cued fear conditioning test, animals that received 1 Gy froze more during the pretone portion of the test, relative to controls and 0.2-Gy-irradiated mice, suggesting enhanced anxiety. Compared to previously reported studies, these data suggest that 28Si-radiation exposure damages neurogenesis, but to a lesser extent than 56Fe radiation and that low-dose 28Si exposure induces abnormalities in hippocampal function, disrupting fear memory but also inducing anxiety-like behavior. Furthermore, exposure to 28Si radiation decreased new neuron survival in long-term male groups but not females suggests that sex may be an important factor when performing brain health risk assessment for astronauts traveling in space.
Collapse
Affiliation(s)
- Cody W. Whoolery
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
| | - Angela K. Walker
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
| | | | - Melanie J. Lucero
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
| | - Ryan P. Reynolds
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
- Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Anesthesiology and Critical Care Medicine, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - David H. Beddow
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
| | - K. Lyles Clark
- Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Hung-Ying Shih
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas
| | - Junie A. LeBlanc
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
| | - Mara G. Cole
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
| | | | - Shibani Mukherjee
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
| | - Shichuan Zhang
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas
| | - Francisca Ahn
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas
| | - Sarah E. Bulin
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
| | | | - Phillip D. Rivera
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
| | - Benjamin P. C. Chen
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas
| | - Sanghee Yun
- Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Anesthesiology and Critical Care Medicine, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Amelia J. Eisch
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
- Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Anesthesiology and Critical Care Medicine, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| |
Collapse
|
32
|
Gualtieri F, Brégère C, Laws GC, Armstrong EA, Wylie NJ, Moxham TT, Guzman R, Boswell T, Smulders TV. Effects of Environmental Enrichment on Doublecortin and BDNF Expression along the Dorso-Ventral Axis of the Dentate Gyrus. Front Neurosci 2017; 11:488. [PMID: 28966570 PMCID: PMC5605570 DOI: 10.3389/fnins.2017.00488] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 08/17/2017] [Indexed: 01/09/2023] Open
Abstract
Adult hippocampal neurogenesis (AHN) in the dentate gyrus is known to respond to environmental enrichment, chronic stress, and many other factors. The function of AHN may vary across the septo-temporal axis of the hippocampus, as different subdivisions are responsible for different functions. The dorsal pole regulates cognitive-related behaviors, while the ventral pole mediates mood-related responses through the hypothalamic-pituitary-adrenal (HPA) axis. In this study, we investigate different methods of quantifying the effect of environmental enrichment on AHN in the dorsal and ventral parts of the dentate gyrus (dDG and vDG). To this purpose, 11-week-old female CD-1 mice were assigned for 8 days to one of two conditions: the Environmental Enrichment (E) group received (i) running wheels, (ii) larger cages, (iii) plastic tunnels, and (iv) bedding with male urine, while the Control (C) group received standard housing. Dorsal CA (Cornu Ammonis) and DG regions were larger in the E than the C animals. Distance run linearly predicted the volume of the dorsal hippocampus, as well as of the intermediate and ventral CA regions. In the dDG, the amount of Doublecortin (DCX) immunoreactivity was significantly higher in E than in C mice. Surprisingly, this pattern was the opposite in the vDG (C > E). Real-time PCR measurement of Dcx mRNA and DCX protein analysis using ELISA showed the same pattern. Brain Derived Neurotrophic Factor (BDNF) immunoreactivity and mRNA displayed no difference between E and C, suggesting that upregulation of DCX was not caused by changes in BDNF levels. BDNF levels were higher in vDG than in dDG, as measured by both methods. Bdnf expression in vDG correlated positively with the distance run by individual E mice. The similarity in the patterns of immunoreactivity, mRNA and protein for differential DCX expression and for BDNF distribution suggests that the latter two methods might be effective tools for more rapid quantification of AHN.
Collapse
Affiliation(s)
- Fabio Gualtieri
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Catherine Brégère
- Brain Ischemia and Regeneration, Department of Biomedicine and Department of Neurosurgery, University Hospital BaselBasel, Switzerland
| | - Grace C Laws
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Elena A Armstrong
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, United Kingdom.,School of Psychology, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Nicholas J Wylie
- School of Psychology, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Theo T Moxham
- School of Psychology, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Raphael Guzman
- Brain Ischemia and Regeneration, Department of Biomedicine and Department of Neurosurgery, University Hospital BaselBasel, Switzerland
| | - Timothy Boswell
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, United Kingdom.,School of Natural and Environmental Sciences, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Tom V Smulders
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| |
Collapse
|
33
|
Schreurs A, Sabanov V, Balschun D. Distinct Properties of Long-Term Potentiation in the Dentate Gyrus along the Dorsoventral Axis: Influence of Age and Inhibition. Sci Rep 2017; 7:5157. [PMID: 28698637 PMCID: PMC5506024 DOI: 10.1038/s41598-017-05358-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 05/26/2017] [Indexed: 02/07/2023] Open
Abstract
The hippocampus is important for spatial navigation, episodic memory and affective behaviour. Increasing evidence suggests that these multiple functions are accomplished by different segments along the dorsal-ventral (septal-temporal) axis. Long-term potentiation (LTP), the best-investigated cellular correlate of learning and memory, has distinct properties along this axis in the CA1 region, but so far, little is known about longitudinal differences in dentate gyrus (DG). Therefore, here we examined potential dorsoventral differences in DG-LTP using in vitro multi-electrode array recordings. In young mice, we found higher basal synaptic transmission in the dorsal DG, while the LTP magnitude markedly increased towards the ventral pole. Strikingly, these differences were greatly reduced in slices from middle-aged mice. Short-term plasticity, evaluated by paired-pulse ratios, was similar across groups. Recordings in the presence and absence of GABAA-receptor blocker picrotoxin suggested a higher inhibitory tone in the ventral DG of young mice, confirmed by an increased frequency of miniature inhibitory postsynaptic currents. Our findings support the view that the hippocampus contains discrete functional domains along its dorsoventral axis and demonstrate that these are subject to age-dependent changes. Since these characteristics are presumably conserved in the human hippocampus, our findings have important clinical implications for hippocampus- and age-related disorders.
Collapse
Affiliation(s)
- An Schreurs
- KU Leuven, Faculty of Psychology and Educational Sciences, Brain & Cognition, Laboratory of Biological Psychology, Leuven, Belgium
| | - Victor Sabanov
- KU Leuven, Faculty of Psychology and Educational Sciences, Brain & Cognition, Laboratory of Biological Psychology, Leuven, Belgium
| | - Detlef Balschun
- KU Leuven, Faculty of Psychology and Educational Sciences, Brain & Cognition, Laboratory of Biological Psychology, Leuven, Belgium.
| |
Collapse
|
34
|
Egeland M, Guinaudie C, Du Preez A, Musaelyan K, Zunszain PA, Fernandes C, Pariante CM, Thuret S. Depletion of adult neurogenesis using the chemotherapy drug temozolomide in mice induces behavioural and biological changes relevant to depression. Transl Psychiatry 2017; 7:e1101. [PMID: 28440814 PMCID: PMC5416706 DOI: 10.1038/tp.2017.68] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 02/15/2017] [Accepted: 02/18/2017] [Indexed: 12/17/2022] Open
Abstract
Numerous studies have examined links between postnatal neurogenesis and depression using a range of experimental methods to deplete neurogenesis. The antimitotic drug temozolomide (TMZ) has previously been used successfully as an experimental tool in animals to deplete adult neurogenesis and is used regularly on human patients as a standard chemotherapy for brain cancer. In this study, we wanted to evaluate whether TMZ as a model for chemotherapy treatment could affect parameters related to depression in an animal model. Prevalence rates of depression in patients is thought to be highly underdiagnosed, with some studies reporting rates as high as 90%. Results from this study in mice, treated with a regimen of TMZ similar to humans, exhibited behavioural and biochemical changes that have relevance to the development of depression. In particular, behavioural results demonstrated robust deficits in processing novelty and a significant increase in the corticosterone response. Quantification of neurogenesis using a novel sectioning method, which clearly evaluates dorsal and ventral neurogenesis separately, showed a significant correlation between the level of ventral neurogenesis and the corticosterone response. Depression is a complex disorder with discoveries regarding its neurobiology and how it relates to behaviour being only in their infancy. The findings presented in this study demonstrate that chemotherapy-induced decreases in neurogenesis results in previously unreported behavioural and biochemical consequences. These results, we argue, are indicative of a biological mechanism, which may contribute to the development of depression in patients being treated with chemotherapy and is separate from the mental distress resulting from a cancer diagnosis.
Collapse
Affiliation(s)
- M Egeland
- Department of Psychological Medicine, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK,Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK,Department of Psychological Medicine, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Cutcombe Road, London SE5 9RT, UK. E-mail: or
| | - C Guinaudie
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - A Du Preez
- Department of Psychological Medicine, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK,MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - K Musaelyan
- Department of Psychological Medicine, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK,Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK,MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - P A Zunszain
- Department of Psychological Medicine, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - C Fernandes
- MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - C M Pariante
- Department of Psychological Medicine, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - S Thuret
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK,Department of Psychological Medicine, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Cutcombe Road, London SE5 9RT, UK. E-mail: or
| |
Collapse
|
35
|
PM 2.5 Exposure Suppresses Dendritic Maturation in Subgranular Zone in Aged Rats. Neurotox Res 2017; 32:50-57. [PMID: 28275902 PMCID: PMC5487878 DOI: 10.1007/s12640-017-9710-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/03/2017] [Accepted: 02/13/2017] [Indexed: 01/19/2023]
Abstract
Detrimental effects of long-term inhalation of fine particulate matter (PM2.5) on the pulmonary and cardiovascular systems have been widely reported. Recent studies have shown that exposure to PM2.5 also causes adverse neurocognitive effects. This study investigates the effects of inhaled ammonium sulfate, which is a major compound of inorganic air pollutants in PM2.5, on adult neurogenesis in aged Sprague-Dawley rats. A total of 20 rats were randomly assigned to experimental (n = 10) and control (n = 10) conditions, wherein they were exposed to either ammonium sulfate or sham air for 2 h per day and for 28 consecutive days. It was observed that ammonium sulfate inhibited the maturation process and diminished dendritic complexity of immature neurons in the subgranular zone (SGZ) of the hippocampus significantly, although the number of neural stem cells or the rates of differentiation were comparable between the two groups. Our findings provide clear evidence on the direct relationship between air quality and advantageous neurogenesis. Exposure to PM leads to specific adverse effects on the maturation process during neurogenesis.
Collapse
|
36
|
Alvarez DD, Giacomini D, Yang SM, Trinchero MF, Temprana SG, Büttner KA, Beltramone N, Schinder AF. A disynaptic feedback network activated by experience promotes the integration of new granule cells. Science 2016; 354:459-465. [PMID: 27789840 DOI: 10.1126/science.aaf2156] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 09/16/2016] [Indexed: 12/12/2022]
Abstract
Experience shapes the development and connectivity of adult-born granule cells (GCs) through mechanisms that are poorly understood. We examined the remodeling of dentate gyrus microcircuits in mice in an enriched environment (EE). Short exposure to EE during early development of new GCs accelerated their functional integration. This effect was mimicked by in vivo chemogenetic activation of a limited population of mature GCs. Slice recordings showed that mature GCs recruit parvalbumin γ-aminobutyric acid-releasing interneurons (PV-INs) that feed back onto developing GCs. Accordingly, chemogenetic stimulation of PV-INs or direct depolarization of developing GCs accelerated GC integration, whereas inactivation of PV-INs prevented the effects of EE. Our results reveal a mechanism for dynamic remodeling in which experience activates dentate networks that "prime" young GCs through a disynaptic feedback loop mediated by PV-INs.
Collapse
Affiliation(s)
- Diego D Alvarez
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Damiana Giacomini
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Sung Min Yang
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Mariela F Trinchero
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Silvio G Temprana
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Karina A Büttner
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Natalia Beltramone
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.
| |
Collapse
|
37
|
Effects of neuregulin-1 administration on neurogenesis in the adult mouse hippocampus, and characterization of immature neurons along the septotemporal axis. Sci Rep 2016; 6:30467. [PMID: 27469430 PMCID: PMC4965755 DOI: 10.1038/srep30467] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 07/04/2016] [Indexed: 12/11/2022] Open
Abstract
Adult hippocampal neurogenesis is associated with learning and affective behavioural regulation. Its diverse functionality is segregated along the septotemporal axis from the dorsal to ventral hippocampus. However, features distinguishing immature neurons in these regions have yet to be characterized. Additionally, although we have shown that administration of the neurotrophic factor neuregulin-1 (NRG1) selectively increases proliferation and overall neurogenesis in the mouse ventral dentate gyrus (DG), likely through ErbB3, NRG1's effects on intermediate neurogenic stages in immature neurons are unknown. We examined whether NRG1 administration increases DG ErbB3 phosphorylation. We labeled adultborn cells using BrdU, then administered NRG1 to examine in vivo neurogenic effects on immature neurons with respect to cell survival, morphology, and synaptogenesis. We also characterized features of immature neurons along the septotemporal axis. We found that neurogenic effects of NRG1 are temporally and subregionally specific to proliferation in the ventral DG. Particular morphological features differentiate immature neurons in the dorsal and ventral DG, and cytogenesis differed between these regions. Finally, we identified synaptic heterogeneity surrounding the granule cell layer. These results indicate neurogenic involvement of NRG1-induced antidepressant-like behaviour is particularly associated with increased ventral DG cell proliferation, and identify novel distinctions between dorsal and ventral hippocampal neurogenic development.
Collapse
|
38
|
Ardalan M, Wegener G, Polsinelli B, Madsen TM, Nyengaard JR. Neurovascular plasticity of the hippocampus one week after a single dose of ketamine in genetic rat model of depression. Hippocampus 2016; 26:1414-1423. [PMID: 27440163 DOI: 10.1002/hipo.22617] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2016] [Indexed: 12/20/2022]
Abstract
Glutamatergic system and the structural plasticity hypothesis are principal components for rapid and sustained antidepressant effects of novel antidepressant therapeutics. This study represents the first investigation of the structural plasticity of the hippocampus as one of the main contributed mechanisms to the sustained anti-depressive effect of ketamine. Flinders Sensitive Line (FSL) and Flinders Resistant Line (FRL) rats were given a single intraperitoneal injection of ketamine (15 mg/kg) or saline 7 days before perfusion-fixed. The optical fractionator method was used to estimate the total number of neurons in the granular cell layer. Microvessel length in the molecular layer of DG was evaluated with global spatial sampling method. By use of the physical disector method, the number of synapses was estimated. The volume of the hippocampus was larger in the FRL-vehicle rats compared with FSL-vehicle group and in FSL-ketamine versus FSL-vehicle rats (P < 0.05). The number of non-perforated synapses was significantly higher in the FSL-ketamine versus FSL-vehicle group, (P = 0.01). A significant effect of ketamine on enhancement of the number of neurons in DG in FSL rats was observed (P = 0.01). The total length of the microvessels 1 week after ketamine treatment in the FSL rats significantly increased (P < 0.05). Our results indicate that neurovascular changes of hippocampus could be one of the possible mechanisms underlying the sustained antidepressant effect of ketamine by reversing alteration of the number of the excitatory synapses, neuronal number and length of the microvessels in the hippocampus. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Maryam Ardalan
- Department of Clinical Medicine, Translational Neuropsychiatry Unit, Aarhus University Hospital, Risskov, Denmark. .,Department of Clinical Medicine, Stereology and Electron Microscopy Laboratory, Aarhus University Hospital, Aarhus, Denmark.
| | - Gregers Wegener
- Department of Clinical Medicine, Translational Neuropsychiatry Unit, Aarhus University Hospital, Risskov, Denmark.,Pharmaceutical Research Center of Excellence, School of Pharmacy (Pharmacology), North-West University, Potchefstroom, South Africa
| | - Benedetta Polsinelli
- Department of Clinical Medicine, Stereology and Electron Microscopy Laboratory, Aarhus University Hospital, Aarhus, Denmark.,Laboratory of Neuropsychopharmacology and Functional Neurogenomics, Dipartimento Di Scienze Farmacologiche E Biomolecolari and Center of Excellence on Neurodegenerative Diseases, Università Degli Studi Di Milano, Milano, Italy
| | | | - Jens R Nyengaard
- Department of Clinical Medicine, Stereology and Electron Microscopy Laboratory, Aarhus University Hospital, Aarhus, Denmark.,Centre for Stochastic Geometry and Advanced Bioimaging (CSGB), Aarhus University, Aarhus, Denmark
| |
Collapse
|
39
|
Castilla-Ortega E, Blanco E, Serrano A, Ladrón de Guevara-Miranda D, Pedraz M, Estivill-Torrús G, Pavón FJ, Rodríguez de Fonseca F, Santín LJ. Pharmacological reduction of adult hippocampal neurogenesis modifies functional brain circuits in mice exposed to a cocaine conditioned place preference paradigm. Addict Biol 2016; 21:575-88. [PMID: 25870909 DOI: 10.1111/adb.12248] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We investigated the role of adult hippocampal neurogenesis in cocaine-induced conditioned place preference (CPP) behaviour and the functional brain circuitry involved. Adult hippocampal neurogenesis was pharmacologically reduced with temozolomide (TMZ), and mice were tested for cocaine-induced CPP to study c-Fos expression in the hippocampus and in extrahippocampal addiction-related areas. Correlational and multivariate analysis revealed that, under normal conditions, the hippocampus showed widespread functional connectivity with other brain areas and strongly contributed to the functional brain module associated with CPP expression. However, the neurogenesis-reduced mice showed normal CPP acquisition but engaged an alternate brain circuit where the functional connectivity of the dentate gyrus was notably reduced and other areas (the medial prefrontal cortex, accumbens and paraventricular hypothalamic nucleus) were recruited instead of the hippocampus. A second experiment unveiled that mice acquiring the cocaine-induced CPP under neurogenesis-reduced conditions were delayed in extinguishing their drug-seeking behaviour. But if the inhibited neurons were generated after CPP acquisition, extinction was not affected but an enhanced long-term CPP retention was found, suggesting that some roles of the adult-born neurons may differ depending on whether they are generated before or after drug-contextual associations are established. Importantly, cocaine-induced reinstatement of CPP behaviour was increased in the TMZ mice, regardless of the time of neurogenesis inhibition. The results show that adult hippocampal neurogenesis sculpts the addiction-related functional brain circuits, and reduction of the adult-born hippocampal neurons increases cocaine seeking in the CPP model.
Collapse
Affiliation(s)
- Estela Castilla-Ortega
- Unidad de Gestión Clínica de Salud Mental; Instituto de Investigación Biomédica de Málaga (IBIMA); Hospital Regional Universitario de Málaga; Spain
| | - Eduardo Blanco
- Departament de Pedagogia i Psicología; Facultat d'Educació, Psicologia i Treball Social; Universitat de Lleida; Spain
| | - Antonia Serrano
- Unidad de Gestión Clínica de Salud Mental; Instituto de Investigación Biomédica de Málaga (IBIMA); Hospital Regional Universitario de Málaga; Spain
| | - David Ladrón de Guevara-Miranda
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento; Instituto de Investigación Biomédica de Málaga (IBIMA); Facultad de Psicología; Universidad de Málaga; Spain
| | - María Pedraz
- Unidad de Gestión Clínica de Salud Mental; Instituto de Investigación Biomédica de Málaga (IBIMA); Hospital Regional Universitario de Málaga; Spain
| | - Guillermo Estivill-Torrús
- Unidad de Gestión Clínica Intercentros de Neurociencias y ECAI de Microscopía; Instituto de Investigación Biomédica de Málaga (IBIMA); Hospitales Universitarios Regional de Málaga y Virgen de la Victoria; Spain
| | - Francisco Javier Pavón
- Unidad de Gestión Clínica de Salud Mental; Instituto de Investigación Biomédica de Málaga (IBIMA); Hospital Regional Universitario de Málaga; Spain
| | - Fernando Rodríguez de Fonseca
- Unidad de Gestión Clínica de Salud Mental; Instituto de Investigación Biomédica de Málaga (IBIMA); Hospital Regional Universitario de Málaga; Spain
| | - Luis J. Santín
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento; Instituto de Investigación Biomédica de Málaga (IBIMA); Facultad de Psicología; Universidad de Málaga; Spain
| |
Collapse
|
40
|
Castilla-Ortega E, Serrano A, Blanco E, Araos P, Suárez J, Pavón FJ, Rodríguez de Fonseca F, Santín LJ. A place for the hippocampus in the cocaine addiction circuit: Potential roles for adult hippocampal neurogenesis. Neurosci Biobehav Rev 2016; 66:15-32. [PMID: 27118134 DOI: 10.1016/j.neubiorev.2016.03.030] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 03/08/2016] [Accepted: 03/08/2016] [Indexed: 02/07/2023]
Abstract
Cocaine addiction is a chronic brain disease in which the drug seeking habits and profound cognitive, emotional and motivational alterations emerge from drug-induced neuroadaptations on a vulnerable brain. Therefore, a 'cocaine addiction brain circuit' has been described to explain this disorder. Studies in both cocaine patients and rodents reveal the hippocampus as a main node in the cocaine addiction circuit. The contribution of the hippocampus to cocaine craving and the associated memories is essential to understand the chronic relapsing nature of addiction, which is the main obstacle for the recovery. Interestingly, the hippocampus holds a particular form of plasticity that is rare in the adult brain: the ability to generate new functional neurons. There is an active scientific debate on the contributions of these new neurons to the addicted brain. This review focuses on the potential role(s) of adult hippocampal neurogenesis (AHN) in cocaine addiction. Although the current evidence primarily originates from animal research, these preclinical studies support AHN as a relevant component for the hippocampal effects of cocaine.
Collapse
Affiliation(s)
- Estela Castilla-Ortega
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain.
| | - Antonia Serrano
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain
| | - Eduardo Blanco
- Departament de Pedagogia i Psicologia, Facultat d'Educació, Psicologia i Treball Social, Universitat de Lleida, Spain
| | - Pedro Araos
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain
| | - Juan Suárez
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain
| | - Francisco J Pavón
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain
| | - Fernando Rodríguez de Fonseca
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain
| | - Luis J Santín
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Instituto de Investigación Biomédica de Málaga (IBIMA), Facultad de Psicología, Universidad de Málaga, Spain.
| |
Collapse
|
41
|
Low excitatory innervation balances high intrinsic excitability of immature dentate neurons. Nat Commun 2016; 7:11313. [PMID: 27095423 PMCID: PMC4843000 DOI: 10.1038/ncomms11313] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 03/11/2016] [Indexed: 01/22/2023] Open
Abstract
Persistent neurogenesis in the dentate gyrus produces immature neurons with high intrinsic excitability and low levels of inhibition that are predicted to be more broadly responsive to afferent activity than mature neurons. Mounting evidence suggests that these immature neurons are necessary for generating distinct neural representations of similar contexts, but it is unclear how broadly responsive neurons help distinguish between similar patterns of afferent activity. Here we show that stimulation of the entorhinal cortex in mouse brain slices paradoxically generates spiking of mature neurons in the absence of immature neuron spiking. Immature neurons with high intrinsic excitability fail to spike due to insufficient excitatory drive that results from low innervation rather than silent synapses or low release probability. Our results suggest that low synaptic connectivity prevents immature neurons from responding broadly to cortical activity, potentially enabling excitable immature neurons to contribute to sparse and orthogonal dentate representations. Immature dentate gyrus neurons are highly excitable and are thought to be more responsive to afferent activity than mature neurons. Here, the authors find stimulation of the entorhinal cortex paradoxically generates spiking in mature rather than immature neurons due to low synaptic connectivity of immature cells.
Collapse
|
42
|
Gallitano AL, Satvat E, Gil M, Marrone DF. Distinct dendritic morphology across the blades of the rodent dentate gyrus. Synapse 2016; 70:277-282. [PMID: 26926290 DOI: 10.1002/syn.21900] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 02/23/2016] [Accepted: 02/24/2016] [Indexed: 11/09/2022]
Abstract
The dentate gyrus (DG) is a hippocampal region that has long been characterized as a critical mediator of enduring memory formation and retrieval. As such, there is a wealth of studies investigating this area. Most of these studies have either treated the DG as a homogeneous structure, or examined differences in neurons along the septal-temporal axis. Recent data, however, have indicated that a functional distinction exists between the suprapyramidal and infrapyramidal blades of the DG, with the former showing more robust responses during spatial tasks. To date, few anatomical studies have addressed this functional gradient in rats, and no study has done so in the mouse. To address this, we investigated dendritic morphology and spine density in hippocampal granule cells of rats and mice using the Golgi-Cox technique. We find that granule cells from the suprapyramidal blade of the DG contain greater dendritic material in the region receiving spatial information from the medial perforant path. This provides a potential anatomical substrate for the asymmetric response of the DG to spatial input. Synapse 70:277-282, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Amelia L Gallitano
- Department of Basic Medical Sciences, University of Arizona, Phoenix, AZ, 85004
| | - Elham Satvat
- School of Public Health & Health Systems, University of Waterloo, Waterloo, ON, Canada, N2L 3G1
| | - Mario Gil
- Department of Basic Medical Sciences, University of Arizona, Phoenix, AZ, 85004
| | - Diano F Marrone
- Department of Psychology, Wilfrid Laurier University, Waterloo, ON, Canada, N2L 3C5.,McKnight Brain Institute, University of Arizona, Tucson, AZ, 85724
| |
Collapse
|
43
|
Bonaguidi MA, Stadel RP, Berg DA, Sun J, Ming GL, Song H. Diversity of Neural Precursors in the Adult Mammalian Brain. Cold Spring Harb Perspect Biol 2016; 8:a018838. [PMID: 26988967 DOI: 10.1101/cshperspect.a018838] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Aided by advances in technology, recent studies of neural precursor identity and regulation have revealed various cell types as contributors to ongoing cell genesis in the adult mammalian brain. Here, we use stem-cell biology as a framework to highlight the diversity of adult neural precursor populations and emphasize their hierarchy, organization, and plasticity under physiological and pathological conditions.
Collapse
Affiliation(s)
- Michael A Bonaguidi
- Institute for Cell Engineering, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 Department of Neurology, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana 70130-2685
| | - Ryan P Stadel
- Institute for Cell Engineering, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 Human Genetics Predoctoral Program, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Daniel A Berg
- Institute for Cell Engineering, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 Department of Neurology, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Jiaqi Sun
- Institute for Cell Engineering, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Guo-li Ming
- Institute for Cell Engineering, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 Department of Neurology, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana 70130-2685 The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Hongjun Song
- Institute for Cell Engineering, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 Department of Neurology, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana 70130-2685 Human Genetics Predoctoral Program, The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| |
Collapse
|
44
|
Effects of long-term methylphenidate treatment in adolescent and adult rats on hippocampal shape, functional connectivity and adult neurogenesis. Neuroscience 2015; 309:243-58. [DOI: 10.1016/j.neuroscience.2015.04.044] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 03/31/2015] [Accepted: 04/21/2015] [Indexed: 12/13/2022]
|
45
|
A septo-temporal molecular gradient of sfrp3 in the dentate gyrus differentially regulates quiescent adult hippocampal neural stem cell activation. Mol Brain 2015; 8:52. [PMID: 26337530 PMCID: PMC4559945 DOI: 10.1186/s13041-015-0143-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 08/25/2015] [Indexed: 12/13/2022] Open
Abstract
Background A converging body of evidence indicates that levels of adult hippocampal neurogenesis vary along the septo-temporal axis of the dentate gyrus, but the molecular mechanisms underlying this regional heterogeneity are not known. We previously identified a niche mechanism regulating proliferation and neuronal development in the adult mouse dentate gyrus resulting from the activity-regulated expression of secreted frizzled-related protein 3 (sfrp3) by mature neurons, which suppresses activation of radial glia-like neural stem cells (RGLs) through inhibition of Wingless/INT (WNT) protein signaling. Results Here, we show that activation rates within the quiescent RGL population decrease gradually along the septo-temporal axis in the adult mouse dentate gyrus, as defined by MCM2 expression in RGLs. Using in situ hybridization and quantitative real-time PCR, we identified an inverse septal-to-temporal increase in the expression of sfrp3 that emerges during postnatal development. Elimination of sfrp3 and its molecular gradient leads to increased RGL activation, preferentially in the temporal region of the adult dentate gyrus. Conclusions Our study identifies a niche mechanism that contributes to the graded distribution of neurogenesis in the adult dentate gyrus and has important implications for understanding functional differences associated with adult hippocampal neurogenesis along the septo-temporal axis.
Collapse
|
46
|
Deusser J, Schmidt S, Ettle B, Plötz S, Huber S, Müller CP, Masliah E, Winkler J, Kohl Z. Serotonergic dysfunction in the A53T alpha-synuclein mouse model of Parkinson's disease. J Neurochem 2015. [PMID: 26201615 DOI: 10.1111/jnc.13253] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Parkinson's disease, neuropathologically defined by the aggregation of α-synuclein, is characterized by neuropsychiatric symptoms such as depression and anxiety preceding the onset of motor symptoms. A loss of serotonergic neurons or their projections into the hippocampus and alterations in serotonin release may be linked to these symptoms. Here, we investigate the effect of human A53T α-synuclein on serotonergic neurons using 12-months-old transgenic mice. We detected human α-synuclein in the perikarya of brainstem median and dorsal raphe neurons as well as in serotonergic fibers in the hippocampus. Despite intracellular α-synuclein accumulation there was no loss of serotonergic neurons in dorsal and median raphe nuclei of A53T α-synuclein mice. However, serotonin levels were significantly reduced in the brainstem. In addition, serotonergic fiber density in the dorsal dentate gyrus was significantly less dense in transgenic mice. Interestingly, we detected a significantly compromised increase in doublecortin+ neuroblasts after chronic treatment with fluoxetine at the site of reduced serotonergic innervation, the infrapyramidal blade of the dorsal dentate gyrus in A53T α-synuclein mice. This suggests that α-synuclein affects serotonergic projections in a spatially distinct pattern within the hippocampus thereby influencing the response to antidepressant treatment.
Collapse
Affiliation(s)
- Janina Deusser
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Stefanie Schmidt
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Benjamin Ettle
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Sonja Plötz
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Sabine Huber
- Section of Addiction Medicine, Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Christian P Müller
- Section of Addiction Medicine, Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Eliezer Masliah
- Department of Neurosciences and Pathology, University of California San Diego, La Jolla, California, USA
| | - Jürgen Winkler
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Zacharias Kohl
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| |
Collapse
|
47
|
Radic T, Al-Qaisi O, Jungenitz T, Beining M, Schwarzacher SW. Differential Structural Development of Adult-Born Septal Hippocampal Granule Cells in the Thy1-GFP Mouse, Nuclear Size as a New Index of Maturation. PLoS One 2015; 10:e0135493. [PMID: 26267362 PMCID: PMC4534292 DOI: 10.1371/journal.pone.0135493] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 07/22/2015] [Indexed: 11/20/2022] Open
Abstract
Adult neurogenesis is frequently studied in the mouse hippocampus. We examined the morphological development of adult-born, immature granule cells in the suprapyramidal blade of the septal dentate gyrus over the period of 7–77 days after mitosis with BrdU-labeling in 6-weeks-old male Thy1-GFP mice. As Thy1-GFP expression was restricted to maturated granule cells, it was combined with doublecortin-immunolabeling of immature granule cells. We developed a novel classification system that is easily applicable and enables objective and direct categorization of newborn granule cells based on the degree of dendritic development in relation to the layer specificity of the dentate gyrus. The structural development of adult-generated granule cells was correlated with age, albeit with notable differences in the time course of development between individual cells. In addition, the size of the nucleus, immunolabeled with the granule cell specific marker Prospero-related homeobox 1 gene, was a stable indicator of the degree of a cell's structural maturation and could be used as a straightforward parameter of granule cell development. Therefore, further studies could employ our doublecortin-staging system and nuclear size measurement to perform investigations of morphological development in combination with functional studies of adult-born granule cells. Furthermore, the Thy1-GFP transgenic mouse model can be used as an additional investigation tool because the reporter gene labels granule cells that are 4 weeks or older, while very young cells could be visualized through the immature marker doublecortin. This will enable comparison studies regarding the structure and function between young immature and older matured granule cells.
Collapse
Affiliation(s)
- Tijana Radic
- Institute of Clinical Neuroanatomy, NeuroScience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Omar Al-Qaisi
- Institute of Clinical Neuroanatomy, NeuroScience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Tassilo Jungenitz
- Institute of Clinical Neuroanatomy, NeuroScience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Marcel Beining
- Institute of Clinical Neuroanatomy, NeuroScience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Stephan W. Schwarzacher
- Institute of Clinical Neuroanatomy, NeuroScience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
- * E-mail:
| |
Collapse
|
48
|
Wu MV, Sahay A, Duman RS, Hen R. Functional differentiation of adult-born neurons along the septotemporal axis of the dentate gyrus. Cold Spring Harb Perspect Biol 2015; 7:a018978. [PMID: 26238355 DOI: 10.1101/cshperspect.a018978] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Over the past several decades, the proliferation and integration of adult-born neurons into existing hippocampal circuitry has been implicated in a wide range of behaviors, including novelty recognition, pattern separation, spatial learning, anxiety behaviors, and antidepressant response. In this review, we suggest that the diversity in behavioral requirements for new neurons may be partly caused by separate functional roles of individual neurogenic niches. Growing evidence shows that the hippocampal formation can be compartmentalized not only along the classic trisynaptic circuit, but also along a longitudinal septotemporal axis. We suggest that subpopulations of hippocampal adult-born neurons may be specialized for distinct mnemonic- or mood-related behavioral tasks. We will examine the literature supporting a functional and anatomical dissociation of the hippocampus along the longitudinal axis and discuss techniques to functionally dissect the roles of adult-born hippocampal neurons in these distinct subregions.
Collapse
Affiliation(s)
- Melody V Wu
- Department of Psychiatry, Columbia University, New York, New York 10027 Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, New York 10032
| | - Amar Sahay
- Center for Regenerative Medicine and Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts 02114 Harvard Stem Cell Institute and Harvard Medical School, Boston, Massachusetts 02115
| | - Ronald S Duman
- Department of Psychiatry, Yale University, New Haven, Connecticut 06520 Department of Neurobiology, Yale University, New Haven, Connecticut 06520
| | - René Hen
- Department of Psychiatry, Columbia University, New York, New York 10027 Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, New York 10032 Department of Neuroscience, Columbia University, New York, New York 10027 Department of Pharmacology, Columbia University, New York, New York 10027
| |
Collapse
|
49
|
Enikolopov G, Overstreet-Wadiche L, Ge S. Viral and transgenic reporters and genetic analysis of adult neurogenesis. Cold Spring Harb Perspect Biol 2015; 7:a018804. [PMID: 26238354 DOI: 10.1101/cshperspect.a018804] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Stem and progenitor cells of the developing and adult brain can be effectively identified and manipulated using reporter genes, introduced into transgenic reporter mouse lines or recombinant viruses. Such reporters rely on an ever-increasing variety of fluorescent proteins and a continuously expanding list of regulatory elements and of mouse lines engineered for cell- or time-specific recombination. An important extension of stem-cell-based genetic strategies is an opportunity to explore the properties of newly generated neurons and their contribution to synaptic plasticity. Here, we review available strategies for marking and quantifying various classes of stem and progenitor cells in the adult brain, genetically tracing their progeny, and studying the properties of stem cells and new neurons. We compare various experimental approaches to labeling and investigating stem cells and their progeny and discuss caveats and limitations inherent to each approach.
Collapse
Affiliation(s)
| | | | - Shaoyu Ge
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, New York 11794
| |
Collapse
|
50
|
Workman JL, Raineki C, Weinberg J, Galea LAM. Alcohol and pregnancy: Effects on maternal care, HPA axis function, and hippocampal neurogenesis in adult females. Psychoneuroendocrinology 2015; 57:37-50. [PMID: 25900594 PMCID: PMC4437880 DOI: 10.1016/j.psyneuen.2015.03.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 02/28/2015] [Accepted: 03/01/2015] [Indexed: 01/02/2023]
Abstract
Chronic alcohol consumption negatively affects health, and has additional consequences if consumption occurs during pregnancy as prenatal alcohol exposure adversely affects offspring development. While much is known on the effects of prenatal alcohol exposure in offspring less is known about effects of alcohol in dams. Here, we examine whether chronic alcohol consumption during gestation alters maternal behavior, hippocampal neurogenesis and HPA axis activity in late postpartum female rats compared with nulliparous rats. Rats were assigned to alcohol, pair-fed or ad libitum control treatment groups for 21 days (for pregnant rats, this occurred gestation days 1-21). Maternal behavior was assessed throughout the postpartum period. Twenty-one days after alcohol exposure, we assessed doublecortin (DCX) (an endogenous protein expressed in immature neurons) expression in the dorsal and ventral hippocampus and HPA axis activity. Alcohol consumption during pregnancy reduced nursing and increased self-directed and negative behaviors, but spared licking and grooming behavior. Alcohol consumption increased corticosterone and adrenal mass only in nulliparous females. Surprisingly, alcohol consumption did not alter DCX-expressing cell density. However, postpartum females had fewer DCX-expressing cells (and of these cells more immature proliferating cells but fewer postmitotic cells) than nulliparous females. Collectively, these data suggest that alcohol consumption during pregnancy disrupts maternal care without affecting HPA function or neurogenesis in dams. Conversely, alcohol altered HPA function in nulliparous females only, suggesting that reproductive experience buffers the long-term effects of alcohol on the HPA axis.
Collapse
Affiliation(s)
- Joanna L. Workman
- Department of Psychology University of British Columbia 2136 West Mall Vancouver, BC, Canada V6T 1Z4
| | - Charlis Raineki
- Department of Cellular & Physiological Sciences University of British Columbia 2350 Health Sciences Mall Vancouver, BC, Canada V6T 1Z3
| | - Joanne Weinberg
- Department of Psychology University of British Columbia 2136 West Mall Vancouver, BC, Canada V6T 1Z4
- Department of Cellular & Physiological Sciences University of British Columbia 2350 Health Sciences Mall Vancouver, BC, Canada V6T 1Z3
- Djavad Mowafaghian Centre for Brain Health 2215 Wesbrook Mall Vancouver, BC Canada V6T 1Z3
| | - Liisa A. M. Galea
- Department of Psychology University of British Columbia 2136 West Mall Vancouver, BC, Canada V6T 1Z4
- Djavad Mowafaghian Centre for Brain Health 2215 Wesbrook Mall Vancouver, BC Canada V6T 1Z3
| |
Collapse
|