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Ma Y, Qiao Y, Gao X. Potential role of hippocampal neurogenesis in spinal cord injury induced post-trauma depression. Neural Regen Res 2024; 19:2144-2156. [PMID: 38488549 PMCID: PMC11034606 DOI: 10.4103/1673-5374.392855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 11/02/2023] [Accepted: 11/29/2023] [Indexed: 04/24/2024] Open
Abstract
It has been reported both in clinic and rodent models that beyond spinal cord injury directly induced symptoms, such as paralysis, neuropathic pain, bladder/bowel dysfunction, and loss of sexual function, there are a variety of secondary complications, including memory loss, cognitive decline, depression, and Alzheimer's disease. The large-scale longitudinal population-based studies indicate that post-trauma depression is highly prevalent in spinal cord injury patients. Yet, few basic studies have been conducted to address the potential molecular mechanisms. One of possible factors underlying the depression is the reduction of adult hippocampal neurogenesis which may come from less physical activity, social isolation, chronic pain, and elevated neuroinflammation after spinal cord injury. However, there is no clear consensus yet. In this review, we will first summarize the alteration of hippocampal neurogenesis post-spinal cord injury. Then, we will discuss possible mechanisms underlie this important spinal cord injury consequence. Finally, we will outline the potential therapeutic options aimed at enhancing hippocampal neurogenesis to ameliorate depression.
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Affiliation(s)
- Ying Ma
- Spinal Cord and Brain Injury Research Group, Stark Neuroscience Research Institute, Indianapolis, IN, USA
- Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Yue Qiao
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Xiang Gao
- Spinal Cord and Brain Injury Research Group, Stark Neuroscience Research Institute, Indianapolis, IN, USA
- Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
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2
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Nachtigall EG, de C Myskiw J, Izquierdo I, Furini CRG. Cellular mechanisms of contextual fear memory reconsolidation: Role of hippocampal SFKs, TrkB receptors and GluN2B-containing NMDA receptors. Psychopharmacology (Berl) 2024; 241:61-73. [PMID: 37700085 DOI: 10.1007/s00213-023-06463-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 08/31/2023] [Indexed: 09/14/2023]
Abstract
Memories are stored into long-term representations through a process that depends on protein synthesis. However, a consolidated memory is not static and inflexible and can be reactivated under certain circumstances, the retrieval is able to reactivate memories and destabilize them engaging a process of restabilization known as reconsolidation. Although the molecular mechanisms that mediate fear memory reconsolidation are not entirely known, so here we investigated the molecular mechanisms in the hippocampus involved in contextual fear conditioning memory (CFC) reconsolidation in male Wistar rats. We demonstrated that the blockade of Src family kinases (SFKs), GluN2B-containing NMDA receptors and TrkB receptors (TrkBR) in the CA1 region of the hippocampus immediately after the reactivation session impaired contextual fear memory reconsolidation. These impairments were blocked by the neurotrophin BDNF and the NMDAR agonist, D-Serine. Considering that the study of the link between synaptic proteins is crucial for understanding memory processes, targeting the reconsolidation process may provide new ways of disrupting maladaptive memories, such as those seen in post-traumatic stress disorder. Here we provide new insights into the cellular mechanisms involved in contextual fear memory reconsolidation, demonstrating that SFKs, GluN2B-containing NMDAR, and TrkBR are necessary for the reconsolidation process. Our findings suggest a link between BDNF and SFKs and GluN2B-containing NMDAR as well as a link between NMDAR and SFKs and TrkBR in fear memory reconsolidation. These preliminary pharmacological findings provide new evidence of the mechanisms involved in the reconsolidation of fear memory and have the potential to contribute to the development of treatments for psychiatric disorders involving maladaptive memories.
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Affiliation(s)
- Eduarda G Nachtigall
- Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 3rd floor, Porto Alegre, RS, 90610-000, Brazil
- Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd floor - HSL, Porto Alegre, RS, 90610-000, Brazil
| | - Jociane de C Myskiw
- Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd floor - HSL, Porto Alegre, RS, 90610-000, Brazil
| | - Ivan Izquierdo
- Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd floor - HSL, Porto Alegre, RS, 90610-000, Brazil
| | - Cristiane R G Furini
- Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 3rd floor, Porto Alegre, RS, 90610-000, Brazil.
- Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd floor - HSL, Porto Alegre, RS, 90610-000, Brazil.
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3
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Canatelli-Mallat M, Chiavellini P, Lehmann M, Goya RG, Morel GR. AGE-RELATED LOSS OF RECOGNITION MEMORY AND ITS CORRELATION WITH HIPPOCAMPAL AND PERIRHINAL CORTEX CHANGES IN FEMALE SPRAGUE-DAWLEY RATS. Behav Brain Res 2022; 435:114026. [DOI: 10.1016/j.bbr.2022.114026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/20/2022] [Accepted: 07/24/2022] [Indexed: 11/02/2022]
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4
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Ghosh-Swaby OR, Reichelt AC, Sheppard PAS, Davies J, Bussey TJ, Saksida LM. Metabolic hormones mediate cognition. Front Neuroendocrinol 2022; 66:101009. [PMID: 35679900 DOI: 10.1016/j.yfrne.2022.101009] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 05/18/2022] [Accepted: 06/02/2022] [Indexed: 11/16/2022]
Abstract
Recent biochemical and behavioural evidence indicates that metabolic hormones not only regulate energy intake and nutrient content, but also modulate plasticity and cognition in the central nervous system. Disruptions in metabolic hormone signalling may provide a link between metabolic syndromes like obesity and diabetes, and cognitive impairment. For example, altered metabolic homeostasis in obesity is a strong determinant of the severity of age-related cognitive decline and neurodegenerative disease. Here we review the evidence that eating behaviours and metabolic hormones-particularly ghrelin, leptin, and insulin-are key players in the delicate regulation of neural plasticity and cognition. Caloric restriction and antidiabetic therapies, both of which affect metabolic hormone levels can restore metabolic homeostasis and enhance cognitive function. Thus, metabolic hormone pathways provide a promising target for the treatment of cognitive decline.
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Affiliation(s)
- Olivia R Ghosh-Swaby
- Schulich School of Medicine and Dentistry, Neuroscience Program, Western University, London, ON, Canada
| | - Amy C Reichelt
- Faculty of Health and Medical Sciences, Adelaide Medical School, Adelaide, Australia
| | - Paul A S Sheppard
- Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | - Jeffrey Davies
- Swansea University Medical School, Swansea University, Swansea, UK
| | - Timothy J Bussey
- Schulich School of Medicine and Dentistry, Neuroscience Program, Western University, London, ON, Canada; Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | - Lisa M Saksida
- Schulich School of Medicine and Dentistry, Neuroscience Program, Western University, London, ON, Canada; Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, Western University, London, ON, Canada.
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5
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The spontaneous location recognition task for assessing spatial pattern separation and memory across a delay in rats and mice. Nat Protoc 2021; 16:5616-5633. [PMID: 34741153 DOI: 10.1038/s41596-021-00627-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 09/02/2021] [Indexed: 11/08/2022]
Abstract
Keeping similar memories distinct from one another is a critical cognitive process without which we would have difficulty functioning in everyday life. Memories are thought to be kept distinct through the computational mechanism of pattern separation, which reduces overlap between similar input patterns to amplify differences among stored representations. At the behavioral level, impaired pattern separation has been shown to contribute to memory deficits seen in neuropsychiatric and neurodegenerative diseases, including Alzheimer's disease, and in normal aging. This protocol describes the use of the spontaneous location recognition (SLR) task in mice and rats to behaviorally assess spatial pattern separation ability. This two-phase spontaneous memory task assesses the extent to which animals can discriminate and remember object locations presented during the encoding phase. Using three configurations of the task, the similarity of the to-be-remembered locations can be parametrically manipulated by altering the spatial positions of objects-dissimilar, similar or extra similar-to vary the load on pattern separation. Unlike other pattern separation tasks, SLR varies the load on pattern separation during encoding, when pattern separation is thought to occur. Furthermore, SLR can be used in standard rodent behavioral facilities with basic expertise in rodent handling. The entire protocol takes ~20 d from habituation to testing of the animals on all three task configurations. By incorporating breaks between testing, and varying the objects used as landmarks, animals can be tested repeatedly, increasing experimental power by allowing for within-subjects manipulations.
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6
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Annamneedi A, del Angel M, Gundelfinger ED, Stork O, Çalışkan G. The Presynaptic Scaffold Protein Bassoon in Forebrain Excitatory Neurons Mediates Hippocampal Circuit Maturation: Potential Involvement of TrkB Signalling. Int J Mol Sci 2021; 22:ijms22157944. [PMID: 34360710 PMCID: PMC8347324 DOI: 10.3390/ijms22157944] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 12/30/2022] Open
Abstract
A presynaptic active zone organizer protein Bassoon orchestrates numerous important functions at the presynaptic active zone. We previously showed that the absence of Bassoon exclusively in forebrain glutamatergic presynapses (BsnEmx1cKO) in mice leads to developmental disturbances in dentate gyrus (DG) affecting synaptic excitability, morphology, neurogenesis and related behaviour during adulthood. Here, we demonstrate that hyperexcitability of the medial perforant path-to-DG (MPP-DG) pathway in BsnEmx1cKO mice emerges during adolescence and is sustained during adulthood. We further provide evidence for a potential involvement of tropomyosin-related kinase B (TrkB), the high-affinity receptor for brain-derived neurotrophic factor (BDNF), mediated signalling. We detect elevated TrkB protein levels in the dorsal DG of adult mice (~3–5 months-old) but not in adolescent (~4–5 weeks-old) mice. Electrophysiological analysis reveals increased field-excitatory-postsynaptic-potentials (fEPSPs) in the DG of the adult, but not in adolescent BsnEmx1cKO mice. In line with an increased TrkB expression during adulthood in BsnEmx1cKO, blockade of TrkB normalizes the increased synaptic excitability in the DG during adulthood, while no such effect was observed in adolescence. Accordingly, neurogenesis, which has previously been found to be increased in adult BsnEmx1cKO mice, was unaffected at adolescent age. Our results suggest that Bassoon plays a crucial role in the TrkB-dependent postnatal maturation of the hippocampus.
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Affiliation(s)
- Anil Annamneedi
- Institute of Biology, Otto-Von-Guericke University, 39120 Magdeburg, Germany; (M.d.A.); (O.S.)
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany;
- Leibniz Institute for Neurobiology (LIN), RG Neuroplasticity, 39118 Magdeburg, Germany
- Correspondence: (A.A.); (G.Ç.)
| | - Miguel del Angel
- Institute of Biology, Otto-Von-Guericke University, 39120 Magdeburg, Germany; (M.d.A.); (O.S.)
| | - Eckart D. Gundelfinger
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany;
- Leibniz Institute for Neurobiology (LIN), RG Neuroplasticity, 39118 Magdeburg, Germany
- Institute of Pharmacology & Toxicology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany
| | - Oliver Stork
- Institute of Biology, Otto-Von-Guericke University, 39120 Magdeburg, Germany; (M.d.A.); (O.S.)
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany;
| | - Gürsel Çalışkan
- Institute of Biology, Otto-Von-Guericke University, 39120 Magdeburg, Germany; (M.d.A.); (O.S.)
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany;
- Correspondence: (A.A.); (G.Ç.)
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7
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Vyleta NP, Snyder JS. Prolonged development of long-term potentiation at lateral entorhinal cortex synapses onto adult-born neurons. PLoS One 2021; 16:e0253642. [PMID: 34143843 PMCID: PMC8213073 DOI: 10.1371/journal.pone.0253642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/09/2021] [Indexed: 11/18/2022] Open
Abstract
Critical period plasticity at adult-born neuron synapses is widely believed to contribute to the learning and memory functions of the hippocampus. Experience regulates circuit integration and for a transient interval, until cells are ~6 weeks old, new neurons display enhanced long-term potentiation (LTP) at afferent and efferent synapses. Since neurogenesis declines substantially with age, this raises questions about the extent of lasting plasticity offered by adult-born neurons. Notably, however, the hippocampus receives sensory information from two major cortical pathways. Broadly speaking, the medial entorhinal cortex conveys spatial information to the hippocampus via the medial perforant path (MPP), and the lateral entorhinal cortex, via the lateral perforant path (LPP), codes for the cues and items that make experiences unique. While enhanced critical period plasticity at MPP synapses is relatively well characterized, no studies have examined long-term plasticity at LPP synapses onto adult-born neurons, even though the lateral entorhinal cortex is uniquely vulnerable to aging and Alzheimer's pathology. We therefore investigated LTP at LPP inputs both within (4-6 weeks) and beyond (8+ weeks) the traditional critical period. At immature stages, adult-born neurons did not undergo significant LTP at LPP synapses, and often displayed long-term depression after theta burst stimulation. However, over the course of 3-4 months, adult-born neurons displayed increasingly greater amounts of LTP. Analyses of short-term plasticity point towards a presynaptic mechanism, where transmitter release probability declines as cells mature, providing a greater dynamic range for strengthening synapses. Collectively, our findings identify a novel form of new neuron plasticity that develops over an extended interval, and may therefore be relevant for maintaining cognitive function in aging.
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Affiliation(s)
- Nicholas P. Vyleta
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Jason S. Snyder
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
- * E-mail:
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8
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Hita FJ, Bekinschtein P, Ledda F, Paratcha G. Leucine-rich repeats and immunoglobulin-like domains 1 deficiency affects hippocampal dendrite complexity and impairs cognitive function. Dev Neurobiol 2021; 81:774-785. [PMID: 34114331 DOI: 10.1002/dneu.22840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 11/06/2022]
Abstract
Leucine-rich repeat (LRR) transmembrane proteins have been directly linked to neurodevelopmental and cognitive disorders. We have previously shown that the LRR transmembrane protein, leucine-rich repeats and immunoglobulin-like domains 1 (Lrig1), is a physiological regulator of dendrite complexity of hippocampal pyramidal neurons and social behavior. In this study, we performed a battery of behavioral tests to evaluate spatial memory and cognitive capabilities in Lrig1 mutant mice. The cognitive assessment demonstrated deficits in recognition and spatial memory, evaluated by novel object recognition and object location tests. Moreover, we found that Lrig1-deficient mice present specific impairments in the processing of similar but not dissimilar locations in a spatial pattern separation task, which was correlated with an enhanced dendritic growth and branching of Doublecortin-positive immature granule cells of the dentate gyrus. Altogether, these findings indicate that Lrig1 plays an essential role in controlling morphological and functional plasticity in the hippocampus.
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Affiliation(s)
- Francisco Javier Hita
- Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis"(IBCN)- CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Pedro Bekinschtein
- Instituto de Neurociencias Cognitiva y Traslacional (INCYT), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Neurología Cognitiva (INECO), Universidad Favaloro, Buenos Aires, Argentina
| | - Fernanda Ledda
- Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis"(IBCN)- CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina.,Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Buenos Aires, Argentina
| | - Gustavo Paratcha
- Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis"(IBCN)- CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina.,Facultad de Medicina, I° U.A. Histología, Embriología, Biología Celular y Genética, Universidad de Buenos Aires, Buenos Aires, Argentina
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9
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Littlejohn EL, DeSana AJ, Williams HC, Chapman RT, Joseph B, Juras JA, Saatman KE. IGF1-Stimulated Posttraumatic Hippocampal Remodeling Is Not Dependent on mTOR. Front Cell Dev Biol 2021; 9:663456. [PMID: 34095131 PMCID: PMC8174097 DOI: 10.3389/fcell.2021.663456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/26/2021] [Indexed: 01/29/2023] Open
Abstract
Adult hippocampal neurogenesis is stimulated acutely following traumatic brain injury (TBI). However, many hippocampal neurons born after injury develop abnormally and the number that survive long-term is debated. In experimental TBI, insulin-like growth factor-1 (IGF1) promotes hippocampal neuronal differentiation, improves immature neuron dendritic arbor morphology, increases long-term survival of neurons born after TBI, and improves cognitive function. One potential downstream mediator of the neurogenic effects of IGF1 is mammalian target of rapamycin (mTOR), which regulates proliferation as well as axonal and dendritic growth in the CNS. Excessive mTOR activation is posited to contribute to aberrant plasticity related to posttraumatic epilepsy, spurring preclinical studies of mTOR inhibitors as therapeutics for TBI. The degree to which pro-neurogenic effects of IGF1 depend upon upregulation of mTOR activity is currently unknown. Using immunostaining for phosphorylated ribosomal protein S6, a commonly used surrogate for mTOR activation, we show that controlled cortical impact TBI triggers mTOR activation in the dentate gyrus in a time-, region-, and injury severity-dependent manner. Posttraumatic mTOR activation in the granule cell layer (GCL) and dentate hilus was amplified in mice with conditional overexpression of IGF1. In contrast, delayed astrocytic activation of mTOR signaling within the dentate gyrus molecular layer, closely associated with proliferation, was not affected by IGF1 overexpression. To determine whether mTOR activation is necessary for IGF1-mediated stimulation of posttraumatic hippocampal neurogenesis, wildtype and IGF1 transgenic mice received the mTOR inhibitor rapamycin daily beginning at 3 days after TBI, following pulse labeling with bromodeoxyuridine. Compared to wildtype mice, IGF1 overexpressing mice exhibited increased posttraumatic neurogenesis, with a higher density of posttrauma-born GCL neurons at 10 days after injury. Inhibition of mTOR did not abrogate IGF1-stimulated enhancement of posttraumatic neurogenesis. Rather, rapamycin treatment in IGF1 transgenic mice, but not in WT mice, increased numbers of cells labeled with BrdU at 3 days after injury that survived to 10 days, and enhanced the proportion of posttrauma-born cells that differentiated into neurons. Because beneficial effects of IGF1 on hippocampal neurogenesis were maintained or even enhanced with delayed inhibition of mTOR, combination therapy approaches may hold promise for TBI.
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Affiliation(s)
| | | | | | | | | | | | - Kathryn E. Saatman
- Department of Physiology, Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States
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10
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Gilchrist CP, Cumberland AL, Kondos-Devcic D, Hill RA, Khore M, Quezada S, Reichelt AC, Tolcos M. Hippocampal neurogenesis and memory in adolescence following intrauterine growth restriction. Hippocampus 2020; 31:321-334. [PMID: 33320965 DOI: 10.1002/hipo.23291] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/18/2020] [Accepted: 11/15/2020] [Indexed: 12/11/2022]
Abstract
Intrauterine growth restriction (IUGR) is associated with hippocampal alterations that can increase the risk of short-term memory impairments later in life. Despite the role of hippocampal neurogenesis in learning and memory, research into the long-lasting impact of IUGR on these processes is limited. We aimed to determine the effects of IUGR on neuronal proliferation, differentiation and morphology, and on memory function at adolescent equivalent age. At embryonic day (E) 18 (term ∼E22), placental insufficiency was induced in pregnant Wistar rats via bilateral uterine vessel ligation to generate IUGR offspring (n = 10); control offspring (n = 11) were generated via sham surgery. From postnatal day (P) 36-44, spontaneous location recognition (SLR), novel object location and recognition (NOL, NOR), and open field tests were performed. Brains were collected at P45 to assess neurogenesis (immunohistochemistry), dendritic morphology (Golgi staining), and brain-derived neurotrophic factor expression (BDNF; Western blot analysis). In IUGR versus control rats there was no difference in object preference in the NOL or NOR, the similar and dissimilar condition of the SLR task, or in locomotion and anxiety-like behavior in the open field. There was a significant increase in the linear density of immature neurons (DCX+) in the subgranular zone (SGZ) of the dentate gyrus (DG), but no difference in the linear density of proliferating cells (Ki67+) in the SGZ, nor in areal density of mature neurons (NeuN+) or microglia (Iba-1+) in the DG in IUGR rats compared to controls. Dendritic morphology of dentate granule cells did not differ between groups. Protein expression of the BDNF precursor (pro-BDNF), but not mature BDNF, was increased in the hippocampus of IUGR compared with control rats. These findings highlight that while the long-lasting prenatal hypoxic environment may impact brain development, it may not impact hippocampal-dependent learning and memory in adolescence.
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Affiliation(s)
- Courtney P Gilchrist
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Angela L Cumberland
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Delphi Kondos-Devcic
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Rachel A Hill
- Department of Psychiatry, Monash University, Clayton, Victoria, Australia
| | - Madhavi Khore
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Sebastian Quezada
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Amy C Reichelt
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia.,Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Mary Tolcos
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
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11
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Miranda M, Morici JF, Gallo F, Piromalli Girado D, Weisstaub NV, Bekinschtein P. Molecular mechanisms within the dentate gyrus and the perirhinal cortex interact during discrimination of similar nonspatial memories. Hippocampus 2020; 31:140-155. [PMID: 33064924 DOI: 10.1002/hipo.23269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 07/29/2020] [Accepted: 09/13/2020] [Indexed: 12/27/2022]
Abstract
Differentiating between similar memories is a crucial cognitive function that enables correct episodic memory formation. The ability to separate the components of memories into distinct representations is thought to rely on a computational process known as pattern separation, by which differences are amplified to disambiguate similar events. Although pattern separation has been localized to the dentate gyrus (DG) of the hippocampus and shown to occur in a spatial domain, this cognitive function takes place also during processing of other types of information. In particular, there is some debate on whether the DG participates in pattern separation of nonspatial representations. Considering the classic role of the Prh in the acquisition and storage of object memories in general and tasks with similar features in particular, this cognitive function could rely more heavily on perirhinal regions when object-related information is processed. Here we show that two plasticity-related proteins, BDNF, and Arc, are required in the DG for nonspatial mnemonic differentiation. Moreover, we found that the crucial role of the DG is transient since activity of AMPAR is only required in the Prh but not the DG during differentiated object memory retrieval. Additionally, this memory is not modifiable by postacquisition rhBDNF infusions in the DG that are known to improve memory when given in the Prh. This highlights a differential role of Prh and DG during differentiated object memory consolidation. Additionally, we found that these molecular mechanisms actively interact in the DG and Prh for the formation of distinguishable memories, with infusions of rhBDNF in the Prh being able to rescue mnemonic deficits caused by reduced Arc expression in the DG. These results reveal a complex interaction between plasticity mechanisms in the Prh and DG for nonspatial pattern separation and posit the Prh as the key structure where unique object representations are stored.
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Affiliation(s)
- Magdalena Miranda
- Laboratorio de Memoria y Cognición Molecular, Instituto de Neurociencia Cognitiva y Traslacional, CONICET-Fundación INECO-Universidad Favaloro, Solís 453, Buenos Aires, 1071, Argentina
| | - Juan Facundo Morici
- Laboratorio de Memoria y Cognición Molecular, Instituto de Neurociencia Cognitiva y Traslacional, CONICET-Fundación INECO-Universidad Favaloro, Solís 453, Buenos Aires, 1071, Argentina
| | - Francisco Gallo
- Laboratorio de Memoria y Cognición Molecular, Instituto de Neurociencia Cognitiva y Traslacional, CONICET-Fundación INECO-Universidad Favaloro, Solís 453, Buenos Aires, 1071, Argentina
| | - Dinka Piromalli Girado
- Laboratorio de Memoria y Cognición Molecular, Instituto de Neurociencia Cognitiva y Traslacional, CONICET-Fundación INECO-Universidad Favaloro, Solís 453, Buenos Aires, 1071, Argentina
| | - Noelia V Weisstaub
- Laboratorio de Memoria y Cognición Molecular, Instituto de Neurociencia Cognitiva y Traslacional, CONICET-Fundación INECO-Universidad Favaloro, Solís 453, Buenos Aires, 1071, Argentina
| | - Pedro Bekinschtein
- Laboratorio de Memoria y Cognición Molecular, Instituto de Neurociencia Cognitiva y Traslacional, CONICET-Fundación INECO-Universidad Favaloro, Solís 453, Buenos Aires, 1071, Argentina
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12
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Crouzier L, Couly S, Roques C, Peter C, Belkhiter R, Arguel Jacquemin M, Bonetto A, Delprat B, Maurice T. Sigma-1 (σ 1) receptor activity is necessary for physiological brain plasticity in mice. Eur Neuropsychopharmacol 2020; 39:29-45. [PMID: 32893057 DOI: 10.1016/j.euroneuro.2020.08.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/24/2020] [Accepted: 08/25/2020] [Indexed: 12/14/2022]
Abstract
The sigma-1 receptor (S1R) is a membrane-associated protein expressed in neurons and glia at mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs). S1R interacts with different partners to regulate cellular responses, including ER stress, mitochondrial physiology and Ca2+ fluxes. S1R shapes cellular plasticity by directly modulating signaling pathways involved in inflammatory responses, cell survival and death. We here analyzed its impact on brain plasticity in vivo, in mice trained in a complex maze, the Hamlet test. The device, providing strong enriched environment (EE) conditions, mimics a small village. It has a central agora and streets expanding from it, leading to functionalized houses where animals can Drink, Eat, Hide, Run, or Interact. Animals were trained in groups, 4 h/day for two weeks, and their maze exploration and topographic memory could be analyzed. Several groups of mice were considered: non-trained vs. trained; repeatedly administered with saline vs. NE-100, a selective S1R antagonist; and wildtype vs. S1R KO mice. S1R inactivation altered maze exploration and prevented topographic learning. EE induced a strong plasticity measured through resilience to behavioral despair or to the amnesic effects of scopolamine, and increases in S1R expression and bdnf mRNA levels in the hippocampus; increases in neurogenesis (proliferation and maturation); and increases of histone acetylation in the hippocampus and cortex. S1R inactivation altered all these parameters significantly, showing that S1R activity plays a major role in physiological brain plasticity. As S1R is a major resident protein in MAMs, modulating ER responses and mitochondrial homeostasy, MAM physiology appeared impacted by enriched environment.
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Affiliation(s)
- Lucie Crouzier
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
| | - Simon Couly
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
| | - Chloé Roques
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
| | - Coralie Peter
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
| | | | | | - Anna Bonetto
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
| | | | - Tangui Maurice
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France.
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13
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Bonafina A, Trinchero MF, Ríos AS, Bekinschtein P, Schinder AF, Paratcha G, Ledda F. GDNF and GFRα1 Are Required for Proper Integration of Adult-Born Hippocampal Neurons. Cell Rep 2020; 29:4308-4319.e4. [PMID: 31875542 DOI: 10.1016/j.celrep.2019.11.100] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 09/23/2019] [Accepted: 11/21/2019] [Indexed: 11/26/2022] Open
Abstract
The glial cell line-derived neurotrophic factor (GDNF) is required for the survival and differentiation of diverse neuronal populations during nervous system development. Despite the high expression of GDNF and its receptor GFRα1 in the adult hippocampus, the functional role of this system remains unknown. Here, we show that GDNF, acting through its GFRα1 receptor, controls dendritic structure and spine density of adult-born granule cells, which reveals that GFRα1 is required for their integration into preexisting circuits. Moreover, conditional mutant mice for GFRα1 show deficits in behavioral pattern separation, a task in which adult neurogenesis is known to play a critical role. We also find that running increases GDNF in the dentate gyrus and promotes GFRα1-dependent CREB (cAMP response element-binding protein) activation and dendrite maturation. Together, these findings indicate that GDNF/GFRα1 signaling plays an essential role in the plasticity of adult circuits, controlling the integration of newly generated neurons.
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Affiliation(s)
- Antonela Bonafina
- División de Neurobiología Molecular y Celular, Instituto de Biología Celular y Neurociencias, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Mariela Fernanda Trinchero
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Antonella Soledad Ríos
- División de Neurobiología Molecular y Celular, Instituto de Biología Celular y Neurociencias, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina; Laboratorio de Neurobiología Molecular y Celular, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Pedro Bekinschtein
- Instituto de Neurociencia Cognitiva y Translacional, Universidad Favaloro, INECO, CONICET, Buenos Aires, Argentina
| | - Alejandro Fabián Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Gustavo Paratcha
- División de Neurobiología Molecular y Celular, Instituto de Biología Celular y Neurociencias, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina.
| | - Fernanda Ledda
- División de Neurobiología Molecular y Celular, Instituto de Biología Celular y Neurociencias, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina; Laboratorio de Neurobiología Molecular y Celular, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
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14
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Antidepressant-like and memory-enhancing effects of the N-type calcium channel blocker ziconotide in rats. Behav Brain Res 2020; 390:112647. [PMID: 32428635 DOI: 10.1016/j.bbr.2020.112647] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 04/01/2020] [Accepted: 04/06/2020] [Indexed: 02/03/2023]
Abstract
The lack of oral or injectable formulations of ziconotide (ω-conotoxin peptide), a novel analgesic agent, limits research on potential neurobehavioral protective properties of this substance, including antidepressant-like effects. Here we expose rats to a stress paradigm that induces depression and memory impairment to assess the effects of ziconotide treatment. Ziconotide was administered intracerebroventricular (i.c.v.) to rats undergoing stereotaxic surgery at a single dose (1 μg/rat) or in repeated long-term applications (dosage groups: 0.1, 0.3, and 1 μg/rat). The antidepressant activity and memory-enhancing effects of ziconotide were examined via the forced swimming test, the Morris water maze test, and the passive avoidance learning test. Behavioral results showed that long-term i.c.v. ziconotide administration significantly decreased the immobility time and delayed the latency period to immobility in a dose-dependent manner compared to controls. In the passive avoidance learning test, the latency period increased, and in the Morris water maze test, the platform location latency time decreased. A single dose of ziconotide (1 μg/rat) did not show a significant effect on memory function or depression parameters during the same tests. Animals were sacrificed immediately after behavioral testing, and both hippocampi were removed and prepared for BDNF evaluation. Hippocampal BDNF levels were significantly increased in rats receiving long-term i.c.v. ziconotide compared to controls. Our results suggest that long-term consumption of ziconotide may attenuate the severity of depression-like behavior and could be useful for preventing memory impairments in various learning models by elevating BDNF levels.
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15
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Snyder JS, Drew MR. Functional neurogenesis over the years. Behav Brain Res 2020; 382:112470. [PMID: 31917241 PMCID: PMC7769695 DOI: 10.1016/j.bbr.2020.112470] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 01/03/2020] [Indexed: 01/01/2023]
Abstract
There has been interest in the function of adult neurogenesis since its discovery, by Joseph Altman, nearly 60 years ago. While controversy curtailed follow up studies, in the 1990s a second wave of research validated many of Altman's original claims and revealed that factors such as stress and environmental stimulation altered the production of new neurons in the hippocampus. However, only with the advent of tools for manipulating neurogenesis did it become possible to perform causal tests of the function of newborn neurons. Here, we identify approximately 100 studies in which adult neurogenesis was manipulated to study its function. A majority of these studies demonstrate functions for adult neurogenesis in classic hippocampal behaviors such as context learning and spatial memory, as well as emotional behaviors related to stress, anxiety and depression. However, a closer look reveals a number of other, arguably understudied, functions in decision making, temporal association memory, and addiction. In this special issue, we present 16 new studies and review articles that continue to address and clarify the function of adult neurogenesis in behaviors as diverse as memory formation, consolidation and forgetting, pattern separation and discrimination behaviors, addiction, and attention. Reviews of stem cell dynamics and regenerative properties provide insights into the mechanisms by which neurogenesis may be controlled to offset age- and disease-related brain injury. Finally, translation-oriented reviews identify next steps for minimizing the gap between discoveries made in animals and applications for human health. The articles in this issue synthesize and extend what we have learned in the last half century of functional neurogenesis research and identify themes that will define its future.
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Affiliation(s)
- Jason S Snyder
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, V6T 2B5, Canada.
| | - Michael R Drew
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
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16
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Li W, Yu Y, Li D, Xu N, Fang J, Sun Y, Xu M, Wang X, Han X, Zhang X, Lv C, Han F. TLR2 deficiency attenuated chronic intermittent hypoxia-induced neurocognitive deficits. Int Immunopharmacol 2020; 81:106284. [PMID: 32058931 DOI: 10.1016/j.intimp.2020.106284] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/22/2020] [Accepted: 02/02/2020] [Indexed: 12/17/2022]
Abstract
Chronic intermittent hypoxia (CIH) is the main symptom of obstructive sleep apnea syndrome (OSAS) and causes neural damage and cognitive deficits via neuroinflammation. Toll-like receptors (TLRs), especially TLR2, play an important role in neuroinflammation. However, the mechanisms by which TLR2 participates in CIH-induced cognitive deficits remain unclear. In this study, wild-type (WT) and TLR2 knock out (KO) mice were exposed to CIH for 8 weeks, and their social novelty discrimination, spatial learning and memory were severely compromised. Additionally, seriously damaged neurons and abnormally activated glia were observed in the CA1 and dentate gyrus (DG) areas of the hippocampus. Mechanistically, knocking out the TLR2 gene significantly alleviated these pathological changes and improved the behavioral performance. Together, these findings demonstrate that the TLR2-MyD88 signaling pathway might play an important role in CIH-induced cognitive deficits.
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Affiliation(s)
- Wanting Li
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Yan Yu
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China.
| | - Dongze Li
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Na Xu
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Jidong Fang
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Yeying Sun
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Maolei Xu
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Xi Wang
- Yantai Affiliated Hospital of Binzhou Medical University, 717 Jinbu Street, YanTai 264199, China
| | - Xin Han
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Xiuli Zhang
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Changjun Lv
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China.
| | - Fang Han
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China.
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17
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Pawley LC, Hueston CM, O'Leary JD, Kozareva DA, Cryan JF, O'Leary OF, Nolan YM. Chronic intrahippocampal interleukin-1β overexpression in adolescence impairs hippocampal neurogenesis but not neurogenesis-associated cognition. Brain Behav Immun 2020; 83:172-179. [PMID: 31604142 DOI: 10.1016/j.bbi.2019.10.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/02/2019] [Accepted: 10/05/2019] [Indexed: 02/06/2023] Open
Abstract
Both neuroinflammation and adult hippocampal neurogenesis (AHN) are implicated in many neurodegenerative disorders as well as in neuropsychiatric disorders, which often become symptomatic during adolescence. A better knowledge of the impact that chronic neuroinflammation has on the hippocampus during the adolescent period could lead to the discovery of new therapeutics for some of these disorders. The hippocampus is particularly vulnerable to altered concentrations of the pro-inflammatory cytokine interleukin-1β (IL-1β), with elevated levels implicated in the aetiology of neurodegenerative disorders such as Alzheimer's and Parkinson's, and stress-related disorders such as depression. The effect of acutely and chronically elevated concentrations of hippocampal IL-1β have been shown to reduce AHN in adult rodents. However, the effect of exposure to chronic overexpression of hippocampal IL-1β during adolescence, a time of increased vulnerability, hasn't been fully interrogated. Thus, in this study we utilized a lentiviral approach to induce chronic overexpression of IL-1β in the dorsal hippocampus of adolescent male Sprague Dawley rats for 5 weeks, during which time its impact on cognition and hippocampal neurogenesis were examined. A reduction in hippocampal neurogenesis was observed along with a reduced level of neurite branching on hippocampal neurons. However, there was no effect of IL-1β overexpression on performance in pattern separation, novel object recognition or spontaneous alternation in the Y maze. Our study has highlighted that chronic IL-1β overexpression in the hippocampus during the adolescent period exerts a negative impact on neurogenesis independent of cognitive performance, and suggests a degree of resilience of the adolescent hippocampus to inflammatory insult.
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Affiliation(s)
- Lauren C Pawley
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Cara M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - James D O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Danka A Kozareva
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - Olivia F O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland.
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18
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Kozareva DA, Cryan JF, Nolan YM. Born this way: Hippocampal neurogenesis across the lifespan. Aging Cell 2019; 18:e13007. [PMID: 31298475 PMCID: PMC6718573 DOI: 10.1111/acel.13007] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/31/2019] [Accepted: 06/30/2019] [Indexed: 12/30/2022] Open
Abstract
The capability of the mammalian brain to generate new neurons through the lifespan has gained much attention for the promise of new therapeutic possibilities especially for the aging brain. One of the brain regions that maintains a neurogenesis-permissive environment is the dentate gyrus of the hippocampus. Here, new neurons are generated from a pool of multipotent neural progenitor cells to become fully functional neurons that are integrated into the brain circuitry. A growing body of evidence points to the fact that neurogenesis in the adult hippocampus is necessary for certain memory processes, and in mood regulation, while alterations in hippocampal neurogenesis have been associated with a myriad of neurological and psychiatric disorders. More recently, evidence has come to light that new neurons may differ in their vulnerability to environmental and disease-related influences depending on the time during the life course at which they are exposed. Thus, it has been the topic of intense research in recent years. In this review, we will discuss the complex process and associated functional relevance of hippocampal neurogenesis during the embryonic/postnatal period and in adulthood. We consider the implications of hippocampal neurogenesis during the developmentally critical periods of adolescence and older age. We will further consider the literature surrounding hippocampal neurogenesis and its functional role during these critical periods with a view to providing insight into the potential of harnessing neurogenesis for health and therapeutic benefit.
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Affiliation(s)
- Danka A. Kozareva
- Department of Anatomy & NeuroscienceUniversity College CorkCorkIreland
| | - John F. Cryan
- Department of Anatomy & NeuroscienceUniversity College CorkCorkIreland
- APC Microbiome IrelandUniversity College CorkCorkIreland
| | - Yvonne M. Nolan
- Department of Anatomy & NeuroscienceUniversity College CorkCorkIreland
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19
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S-nitrosoglutathione prevents cognitive impairment through epigenetic reprogramming in ovariectomised mice. Biochem Pharmacol 2019; 168:352-365. [DOI: 10.1016/j.bcp.2019.07.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 07/23/2019] [Indexed: 12/22/2022]
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20
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Yu RQ, Cooke M, Seib DR, Zhao J, Snyder JS. Adult neurogenesis promotes efficient, nonspecific search strategies in a spatial alternation water maze task. Behav Brain Res 2019; 376:112151. [PMID: 31445978 DOI: 10.1016/j.bbr.2019.112151] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/01/2019] [Accepted: 08/12/2019] [Indexed: 12/18/2022]
Abstract
Goal-directed navigation requires learning strategies that are efficient and minimize costs. In some cases it may be desirable to flexibly adjust behavioral responses depending on the cues that vary from one episode to the next. In others, successful navigation might be achieved with inflexible, habit-like responses that reduce cognitive load. Adult neurogenesis is believed to contribute to the spatial processing functions of the hippocampus, particularly when behavioral flexibility is required. However, little is known about the role of neurogenesis in spatial navigation when goals are unpredictable or change repeatedly according to certain rules. We hypothesized that neurogenesis is necessary in a spatial navigation task that involves different patterns of reinforcement. Intact and neurogenesis-deficient rats were trained to escape to one of two possible platform locations in a spatial water maze. The platform either repeated in the same location for all trials in a day, alternated between two locations across trials, or randomly moved between the two locations. Neurogenesis selectively enhanced escape performance in the alternating condition, but not by improving platform choice accuracy. Instead, neurogenesis-intact rats made fewer search errors and developed an efficient habit-like strategy where they consistently swam to a preferred location. If the platform was not present, they proceeded to the other possible location. In contrast, neurogenesis-deficient rats were indecisive and navigationally less-efficient. Thus, in conditions where goals follow a predictable spatiotemporal pattern, adult neurogenesis promotes the adoption of navigation strategies that are spatially nonspecific but, nonetheless, accurate and efficient.
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Affiliation(s)
- Ru Qi Yu
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Matthew Cooke
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Desiree R Seib
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Jiaying Zhao
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Jason S Snyder
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada.
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21
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Jones R, Craig G, Bhattacharya J. Brain-Derived Neurotrophic Factor Val66Met Polymorphism Is Associated With a Reduced ERP Component Indexing Emotional Recollection. Front Psychol 2019; 10:1922. [PMID: 31496979 PMCID: PMC6712090 DOI: 10.3389/fpsyg.2019.01922] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 08/05/2019] [Indexed: 12/17/2022] Open
Abstract
The Met allele of the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is associated with reduced functioning of the amygdala and hippocampus. It has been linked to major psychiatric conditions, including depression and post-traumatic stress disorder, and is associated with deficits in episodic memory. The precise mechanisms of the BDNF gene’s influence on emotional memory are not well characterized, especially its impact on recognition. Two electrophysiological experiments of emotional memory were run on two independent samples genotyped for BDNF Val66Met. Event-related potentials (ERPs) corresponding to the recognition of negative and neutral words (Experiment 1, N = 37) and negative and positive words (Experiment 2, N = 23) were recorded, and the late parietal component (LPC), typically associated with conscious recollection, was analyzed. In Experiment 1, a reduced LPC was observed in Met carriers (N = 12) compared to Val homozygotes (N = 25) in the negative condition, but the group difference was not present in the neutral condition. In Experiment 2, the reduced LPC was seen in Met carriers (N = 12) compared to Val homozygotes (N = 11) across both conditions. This study provides the first evidence of an association between the BDNF Val66Met genotype and the late parietal electrophysiological component, suggesting that the conscious experience of emotional recollection may differ according to BDNF Val66Met genotype. Further, these results suggest that this effect is likely due to emotional arousal rather than valence polarity. Results were discussed with reference to the possible mechanisms by which emotional recollection deficits may contribute to psychopathology.
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Affiliation(s)
- Rhiannon Jones
- Department of Psychology, University of Winchester, Winchester, United Kingdom.,Department of Psychology, University of Westminster, London, United Kingdom
| | - Gavin Craig
- Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Joydeep Bhattacharya
- Department of Psychology, Goldsmiths, University of London, London, United Kingdom
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22
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Argyrousi EK, de Nijs L, Lagatta DC, Schlütter A, Weidner MT, Zöller J, van Goethem NP, Joca SR, van den Hove DL, Prickaerts J. Effects of DNA methyltransferase inhibition on pattern separation performance in mice. Neurobiol Learn Mem 2019; 159:6-15. [DOI: 10.1016/j.nlm.2019.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 01/27/2019] [Accepted: 02/02/2019] [Indexed: 10/27/2022]
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23
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Albo Z, Gräff J. The mysteries of remote memory. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0029. [PMID: 29352028 PMCID: PMC5790827 DOI: 10.1098/rstb.2017.0029] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2017] [Indexed: 12/16/2022] Open
Abstract
Long-lasting memories form the basis of our identity as individuals and lie central in shaping future behaviours that guide survival. Surprisingly, however, our current knowledge of how such memories are stored in the brain and retrieved, as well as the dynamics of the circuits involved, remains scarce despite seminal technical and experimental breakthroughs in recent years. Traditionally, it has been proposed that, over time, information initially learnt in the hippocampus is stored in distributed cortical networks. This process-the standard theory of memory consolidation-would stabilize the newly encoded information into a lasting memory, become independent of the hippocampus, and remain essentially unmodifiable throughout the lifetime of the individual. In recent years, several pieces of evidence have started to challenge this view and indicate that long-lasting memories might already ab ovo be encoded, and subsequently stored in distributed cortical networks, akin to the multiple trace theory of memory consolidation. In this review, we summarize these recent findings and attempt to identify the biologically plausible mechanisms based on which a contextual memory becomes remote by integrating different levels of analysis: from neural circuits to cell ensembles across synaptic remodelling and epigenetic modifications. From these studies, remote memory formation and maintenance appear to occur through a multi-trace, dynamic and integrative cellular process ranging from the synapse to the nucleus, and represent an exciting field of research primed to change quickly as new experimental evidence emerges.This article is part of a discussion meeting issue 'Of mice and mental health: facilitating dialogue between basic and clinical neuroscientists'.
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Affiliation(s)
- Zimbul Albo
- Laboratory of Neuroepigenetics, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Féderale Lausanne, CH-1015 Lausanne, Switzerland
| | - Johannes Gräff
- Laboratory of Neuroepigenetics, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Féderale Lausanne, CH-1015 Lausanne, Switzerland
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24
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The role of adult hippocampal neurogenesis in brain health and disease. Mol Psychiatry 2019; 24:67-87. [PMID: 29679070 PMCID: PMC6195869 DOI: 10.1038/s41380-018-0036-2] [Citation(s) in RCA: 362] [Impact Index Per Article: 72.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 01/15/2018] [Accepted: 01/31/2018] [Indexed: 12/18/2022]
Abstract
Adult neurogenesis in the dentate gyrus of the hippocampus is highly regulated by a number of environmental and cell-intrinsic factors to adapt to environmental changes. Accumulating evidence suggests that adult-born neurons may play distinct physiological roles in hippocampus-dependent functions, such as memory encoding and mood regulation. In addition, several brain diseases, such as neurological diseases and mood disorders, have deleterious effects on adult hippocampal neurogenesis, and some symptoms of those diseases can be partially explained by the dysregulation of adult hippocampal neurogenesis. Here we review a possible link between the physiological functions of adult-born neurons and their roles in pathological conditions.
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25
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Brydges NM, Moon A, Rule L, Watkin H, Thomas KL, Hall J. Sex specific effects of pre-pubertal stress on hippocampal neurogenesis and behaviour. Transl Psychiatry 2018; 8:271. [PMID: 30531788 PMCID: PMC6288078 DOI: 10.1038/s41398-018-0322-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/08/2018] [Accepted: 11/13/2018] [Indexed: 12/13/2022] Open
Abstract
Experience of traumatic events in childhood is linked to an elevated risk of developing psychiatric disorders in adulthood. The neurobiological mechanisms underlying this phenomenon are not fully understood. The limbic system, particularly the hippocampus, is significantly impacted by childhood trauma. In particular, it has been hypothesised that childhood stress may impact adult hippocampal neurogenesis (AHN) and related behaviours, conferring increased risk for later mental illness. Stress in utero can lead to impaired hippocampal synaptic plasticity, and stress in the first 2-3 weeks of life reduces AHN in animal models. Less is known about the effects of stress in the post-weaning, pre-pubertal phase, a developmental time-point more akin to human childhood. Therefore, we investigated persistent effects of pre-pubertal stress (PPS) on functional and molecular aspects of the hippocampus. AHN was altered following PPS in male rats only. Specifically males showed reduced production of new neurons following PPS, but increased survival in the ventral dentate gyrus. In adult males, but not females, pattern separation and trace fear conditioning, behaviours that rely heavily on AHN, were also impaired after PPS. PPS also increased the expression of parvalbumin-positive GABAergic interneurons in the ventral dentate gyrus and increased glutamic acid decarboxylase 67 expression in the ventral hilus, in males only. Our results demonstrate the lasting effects of PPS on the hippocampus in a sex- and time-dependent manner, provide a potential mechanistic link between PPS and later behavioural impairments, and highlight sex differences in vulnerability to neuropsychiatric conditions after early-life stress.
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Affiliation(s)
- Nichola Marie Brydges
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK.
| | - Anna Moon
- 0000 0001 0807 5670grid.5600.3Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ UK
| | - Lowenna Rule
- 0000 0001 0807 5670grid.5600.3Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ UK
| | - Holly Watkin
- 0000 0001 0807 5670grid.5600.3Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ UK
| | - Kerrie L. Thomas
- 0000 0001 0807 5670grid.5600.3Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ UK ,0000 0001 0807 5670grid.5600.3School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX UK
| | - Jeremy Hall
- 0000 0001 0807 5670grid.5600.3Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ UK ,0000 0001 0807 5670grid.5600.3MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ UK
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Crowley EK, Nolan YM, Sullivan AM. Exercise as a therapeutic intervention for motor and non-motor symptoms in Parkinson's disease: Evidence from rodent models. Prog Neurobiol 2018; 172:2-22. [PMID: 30481560 DOI: 10.1016/j.pneurobio.2018.11.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 10/25/2018] [Accepted: 11/23/2018] [Indexed: 12/11/2022]
Abstract
Parkinson's disease (PD) is characterised by degeneration of dopaminergic neurons of the nigrostriatal pathway, which leads to the cardinal motor symptoms of the disease - tremor, rigidity and postural instability. A number of non-motor symptoms are also associated with PD, including cognitive impairment, mood disturbances and dysfunction of gastrointestinal and autonomic systems. Current therapies provide symptomatic relief but do not halt the disease process, so there is an urgent need for preventative strategies. Lifestyle interventions such as aerobic exercise have shown potential to lower the risk of developing PD and to alleviate both motor and non-motor symptoms. However, there is a lack of large-scale randomised clinical trials that have employed exercise in PD patients. This review will focus on the evidence from studies on rodent models of PD, for employing exercise as an intervention for both motor and non-motor symptoms.
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Affiliation(s)
- E K Crowley
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Y M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland
| | - A M Sullivan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland.
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27
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Kozareva DA, Foley T, Moloney GM, Cryan JF, Nolan YM. TLX knockdown in the dorsal dentate gyrus of juvenile rats differentially affects adolescent and adult behaviour. Behav Brain Res 2018; 360:36-50. [PMID: 30481511 DOI: 10.1016/j.bbr.2018.11.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/23/2018] [Accepted: 11/23/2018] [Indexed: 12/27/2022]
Abstract
The orphan nuclear receptor TLX is predominantly expressed in the central nervous system and is an important factor regulating the maintenance and self-renewal of neural stem cells from embryonic development through adulthood. In adolescence and adulthood, TLX expression is restricted to the neurogenic niches of the brain: the dentate gyrus of the hippocampus and the subventricular zone. The adolescent period is critical for maturation of the hippocampus with heightened levels of neurogenesis observed in rodents. Therefore, we investigated whether lentiviral silencing of TLX expression (TLX knockdown) in the dorsal dentate gyrus of juvenile rats incurred differential impairments in behaviour during late adolescence and adulthood. Our results showed that knockdown of TLX in the dorsal dentate gyrus led to a decrease in cell proliferation in the dorsal but not ventral dentate gyrus. At a behavioural level we observed differential effects in adolescence and adulthood across a number of parameters. A hyperactive phenotype was present in adolescent but not adult TLX knockdown rats, and an increase in immobility during adolescence and in swimming frequency during adulthood was observed in the forced swim test. There was an increased defecation frequency in the open field during adulthood but not adolescence. There were no changes in cognitive performance on hippocampus-dependent tasks or in anxiety-related behaviours. In conclusion, silencing of TLX in the dorsal dentate gyrus led to impairments in hippocampal-independent behaviours which either did not persist or were reversed during adulthood. The current data highlight the temporal importance and function of the nuclear receptor TLX during development.
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Affiliation(s)
- Danka A Kozareva
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Tara Foley
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Gerard M Moloney
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland.
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28
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Hueston CM, O'Leary JD, Hoban AE, Kozareva DA, Pawley LC, O'Leary OF, Cryan JF, Nolan YM. Chronic interleukin-1β in the dorsal hippocampus impairs behavioural pattern separation. Brain Behav Immun 2018; 74:252-264. [PMID: 30217534 DOI: 10.1016/j.bbi.2018.09.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/31/2018] [Accepted: 09/10/2018] [Indexed: 02/04/2023] Open
Abstract
Understanding the long-term consequences of chronic inflammation in the hippocampus may help to develop therapeutic targets for the treatment of cognitive disorders related to stress, ageing and neurodegeneration. The hippocampus is particularly vulnerable to increases in the pro-inflammatory cytokine interleukin-1β (IL-1β), a mediator of neuroinflammation, with elevated levels implicated in the aetiology of neurodegenerative diseases such as Alzheimer's and Parkinson's, and in stress-related disorders such as depression. Acute increases in hippocampal IL-1β have been shown to impair cognition and reduce adult hippocampal neurogenesis, the birth of new neurons. However, the impact of prolonged increases in IL-1β, as evident in clinical conditions, on cognition has not been fully explored. Therefore, the present study utilized a lentiviral approach to induce long-term overexpression of IL-1β in the dorsal hippocampus of adult male Sprague Dawley rats and examine its impact on cognition. Following three weeks of viral integration, pattern separation, a process involving hippocampal neurogenesis, was impaired in IL-1β-treated rats in both object-location and touchscreen operant paradigms. This was coupled with a decrease in the number and neurite complexity of immature neurons in the hippocampus. Conversely, tasks involving the hippocampus, but not sensitive to disruption of hippocampal neurogenesis, including spontaneous alternation, novel object and location recognition were unaffected. Touchscreen operant visual discrimination, a cognitive task involving the prefrontal cortex, was largely unaffected by IL-1β overexpression. In conclusion, these findings suggest that chronically elevated IL-1β in the hippocampus selectively impairs pattern separation. Inflammatory-mediated disruption of adult hippocampal neurogenesis may contribute to the cognitive decline associated with neurodegenerative and stress-related disorders.
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Affiliation(s)
- Cara M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - James D O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Alan E Hoban
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Danka A Kozareva
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Lauren C Pawley
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Olivia F O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland
| | - Yvonne M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland.
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29
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Miranda M, Kent BA, Morici JF, Gallo F, Saksida LM, Bussey TJ, Weisstaub N, Bekinschtein P. NMDA receptors and BDNF are necessary for discrimination of overlapping spatial and non-spatial memories in perirhinal cortex and hippocampus. Neurobiol Learn Mem 2018; 155:337-343. [PMID: 30172952 DOI: 10.1016/j.nlm.2018.08.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 07/03/2018] [Accepted: 08/29/2018] [Indexed: 01/06/2023]
Abstract
Successful memory involves not only remembering information over time but also keeping memories distinct and less confusable. Discrimination of overlapping representations has been investigated in the dentate gyrus (DG) of the hippocampus and largely in the perirhinal cortex (Prh). In particular, the DG was shown to be important for discrimination of overlapping spatial memories and Prh was shown to be important for discrimination of overlapping object memories. In the present study, we used both a DG-dependent and a Prh-dependent task and manipulated the load of similarity between either spatial or object stimuli during information encoding. We showed that N-methyl-D-aspartate-type glutamate receptors (NMDAr) and BDNF participate of the same cellular network during consolidation of both overlapping object and spatial memories in the Prh and DG, respectively. This argues in favor of conserved cellular mechanisms across regions despite anatomical differences.
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Affiliation(s)
- Magdalena Miranda
- Laboratory of Memory Research and Molecular Cognition, Consejo Nacional de Investigaciones Científicas y Técnicas - Fundación INECO - Universidad Favaloro, Buenos Aires, Argentina
| | - Brianne A Kent
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Juan Facundo Morici
- Laboratory of Memory Research and Molecular Cognition, Consejo Nacional de Investigaciones Científicas y Técnicas - Fundación INECO - Universidad Favaloro, Buenos Aires, Argentina
| | - Francisco Gallo
- Laboratory of Memory Research and Molecular Cognition, Consejo Nacional de Investigaciones Científicas y Técnicas - Fundación INECO - Universidad Favaloro, Buenos Aires, Argentina
| | - Lisa M Saksida
- Department of Psychology and MRC/Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK; Molecular Medicine Research Laboratories, Robarts Research Institute, Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; The Brain and Mind Institute, Western University, London, ON, Canada
| | - Timothy J Bussey
- Department of Psychology and MRC/Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK; Molecular Medicine Research Laboratories, Robarts Research Institute, Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; The Brain and Mind Institute, Western University, London, ON, Canada
| | - Noelia Weisstaub
- Laboratory of Memory Research and Molecular Cognition, Consejo Nacional de Investigaciones Científicas y Técnicas - Fundación INECO - Universidad Favaloro, Buenos Aires, Argentina
| | - Pedro Bekinschtein
- Laboratory of Memory Research and Molecular Cognition, Consejo Nacional de Investigaciones Científicas y Técnicas - Fundación INECO - Universidad Favaloro, Buenos Aires, Argentina.
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30
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Impact of high sucrose diets on the discrimination of spatial and object memories with overlapping features. Physiol Behav 2018; 192:127-133. [DOI: 10.1016/j.physbeh.2018.02.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 02/13/2018] [Accepted: 02/14/2018] [Indexed: 01/06/2023]
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Tong J, Li J, Zhang QS, Yang JK, Zhang L, Liu HY, Liu YZ, Yuan JW, Su XM, Zhang XX, Jiao BH. Delayed cognitive deficits can be alleviated by calcium antagonist nimodipine by downregulation of apoptosis following whole brain radiotherapy. Oncol Lett 2018; 16:2525-2532. [PMID: 30013647 PMCID: PMC6036595 DOI: 10.3892/ol.2018.8968] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 01/29/2018] [Indexed: 01/30/2023] Open
Abstract
Radiation therapy is important for the comprehensive treatment of intracranial tumors. However, the molecular mechanisms underlying the pathogenesis of delayed cognitive dysfunction are not well-defined and effective treatments or prevention measures remain insufficient. In the present study, 60 adult male Wistar rats were randomly divided into three groups, which included a control, whole brain radiotherapy (WBRT) (single dose of 30 Gy of WBRT) and nimodipine (single dose of 30 Gy of WBRT followed by nimodipine injection intraperitoneally) groups. The rats were sacrificed 7 days or 3 months following irradiation. At 3 months, the Morris water maze test was used to assess spatial learning and memory function in rats. The results demonstrated that the WBRT group demonstrated a significantly impaired cognitive performance, decreased numbers of hippocampal Cornu Ammonis (CA)1 neurons and upregulated expression of caspase-3 in the dentate gyrus compared with those in the control and nimodipine groups. Reverse transcription-quantitative polymerase chain reaction analysis demonstrated that the WBRT group exhibited increased ratio of B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 compared with that in control and nimodipine groups on day 7 following irradiation. However, the WBRT group exhibited decreased levels of brain-derived neurotrophic factor (BDNF) compared with that in control and nimodipine groups at 3 months following brain irradiation. The levels of growth-associated protein 43 and amyloid precursor protein between the nimodipine group and WBRT group were not statistically significant. The present study demonstrated that neuron apoptosis may lead to delayed cognitive deficits in the hippocampus, in response to radiotherapy. The cognitive impairment may be alleviated in response to a calcium antagonist nimodipine. The molecular mechanisms involved in nimodipine-mediated protection against cognitive decline may involve the regulation of Bax/Bcl-2 and BDNF in the hippocampus.
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Affiliation(s)
- Jing Tong
- Department of Neurosurgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Juan Li
- Department of Radiotherapy, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Qiu-Shi Zhang
- Department of Neurosurgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Jian-Kai Yang
- Department of Neurosurgery, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
| | - Lei Zhang
- Department of Neurosurgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Hai-Ying Liu
- Department of Neurosurgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Ying-Zi Liu
- Department of Neurosurgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Jiang-Wei Yuan
- Department of Neurosurgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Xu-Ming Su
- Department of Neurosurgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Xue-Xin Zhang
- Department of Neurosurgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Bao-Hua Jiao
- Department of Neurosurgery, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
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32
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Seib DR, Chahley E, Princz-Lebel O, Snyder JS. Intact memory for local and distal cues in male and female rats that lack adult neurogenesis. PLoS One 2018; 13:e0197869. [PMID: 29787617 PMCID: PMC5963786 DOI: 10.1371/journal.pone.0197869] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/09/2018] [Indexed: 12/14/2022] Open
Abstract
The dentate gyrus is essential for remembering the fine details of experiences that comprise episodic memory. Dentate gyrus granule cells receive highly-processed sensory information and are hypothesized to perform a pattern separation function, whereby similar sensory inputs are transformed into orthogonal neural representations. Behaviorally, this is believed to enable distinct memory for highly interfering stimuli. Since the dentate gyrus is comprised of a large number of adult-born neurons, which have unique synaptic wiring and neurophysiological firing patterns, it has been proposed that neurogenesis may contribute to this process in unique ways. Some behavioral evidence exists to support this role, whereby neurogenesis-deficient rodents are impaired at discriminating the fine visuospatial details of experiences. However, the extent to which newborn neurons contribute to dentate gyrus-dependent learning tasks is unclear. Furthermore, since most studies of dentate gyrus function are conducted in male rats, little is known about how females perform in similar situations, and whether there might be sex differences in the function of adult neurogenesis. To address these issues, we examined spatial discrimination memory in transgenic male and female rats that lacked adult neurogenesis. The first task probed memory for the position of local objects in an open field, assessed by behavioral responses to novel object locations. The second task examined memory for distal environmental cues. All rats were able to successfully discriminate local and distal cue changes. Males and females also performed comparably, although females displayed higher levels of rearing and locomotion. Collectively, our results indicate that rats are capable of learning about local and distal cues in the absence of adult neurogenesis.
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Affiliation(s)
- Desiree R. Seib
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Erin Chahley
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Oren Princz-Lebel
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Jason Scott Snyder
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
- * E-mail:
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Di Segni M, Andolina D, Ventura R. Long-term effects of early environment on the brain: Lesson from rodent models. Semin Cell Dev Biol 2018; 77:81-92. [DOI: 10.1016/j.semcdb.2017.09.039] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/20/2017] [Accepted: 09/29/2017] [Indexed: 12/21/2022]
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Beyond good and evil: A putative continuum-sorting hypothesis for the functional role of proBDNF/BDNF-propeptide/mBDNF in antidepressant treatment. Neurosci Biobehav Rev 2018; 90:70-83. [PMID: 29626490 DOI: 10.1016/j.neubiorev.2018.04.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/13/2018] [Accepted: 04/03/2018] [Indexed: 02/07/2023]
Abstract
Depression and posttraumatic stress disorder are assumed to be maladaptive responses to stress and antidepressants are thought to counteract such responses by increasing BDNF (brain-derived neurotrophic factor) levels. BDNF acts through TrkB (tropomyosin-related receptor kinase B) and plays a central role in neuroplasticity. In contrast, both precursor proBDNF and BDNF propeptide (another metabolic product from proBDNF cleavage) have a high affinity to p75 receptor (p75R) and usually convey apoptosis and neuronal shrinkage. Although BDNF and proBDNF/propeptide apparently act in opposite ways, neuronal turnover and remodeling might be a final common way that both act to promote more effective neuronal networking, avoiding neuronal redundancy and the misleading effects of environmental contingencies. This review aims to provide a brief overview about the BDNF functional role in antidepressant action and about p75R and TrkB signaling to introduce the "continuum-sorting hypothesis." The resulting hypothesis suggests that both BDNF/proBDNF and BDNF/propeptide act as protagonists to fine-tune antidepressant-dependent neuroplasticity in crucial brain structures to modulate behavioral responses to stress.
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Dietary influences on cognition. Physiol Behav 2018; 192:118-126. [PMID: 29501837 DOI: 10.1016/j.physbeh.2018.02.052] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/27/2018] [Accepted: 02/28/2018] [Indexed: 01/01/2023]
Abstract
Obesity is a world-wide crisis with profound healthcare and socio-economic implications and it is now clear that the central nervous system (CNS) is a target for the complications of metabolic disorders like obesity. In addition to decreases in physical activity and sedentary lifestyles, diet is proposed to be an important contributor to the etiology and progression of obesity. Unfortunately, there are gaps in our knowledge base related to how dietary choices impact the structural and functional integrity of the CNS. For example, while chronic consumption of hypercaloric diets (increased sugars and fat) contribute to increases in body weight and adiposity characteristic of metabolic disorders, the mechanistic basis for neurocognitive deficits in obesity remains to be determined. In addition, studies indicate that acute consumption of hypercaloric diets impairs performance in a wide variety of cognitive domains, even in normal non-obese control subjects. These results from the clinical and basic science literature indicate that diet can have rapid, as well as long lasting effects on cognitive function. This review summarizes our symposium at the 2017 Society for the Study of Ingestive Behavior (SSIB) meeting that discussed these effects of diet on cognition. Collectively, this review highlights the need for integrated and comprehensive approaches to more fully determine how diet impacts behavior and cognition under physiological conditions and in metabolic disorders like type 2 diabetes mellitus (T2DM) and obesity.
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van der Ven AT, Pape JC, Hermann D, Schloesser R, Genius J, Fischer N, Mößner R, Scherbaum N, Wiltfang J, Rujescu D, Benninghoff J. Methylene Blue (Tetramethylthionine Chloride) Influences the Mobility of Adult Neural Stem Cells: A Potentially Novel Therapeutic Mechanism of a Therapeutic Approach in the Treatment of Alzheimer's Disease. J Alzheimers Dis 2018; 57:531-540. [PMID: 28269766 DOI: 10.3233/jad-160755] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An interest in neurogenesis in the adult human brain as a relevant and targetable process has emerged as a potential treatment option for Alzheimer's disease and other neurodegenerative conditions. The aim of this study was to investigate the effects of tetramethylthionine chloride (methylene blue, MB) on properties of adult murine neural stem cells. Based on recent clinical studies, MB has increasingly been discussed as a potential treatment for Alzheimer's disease. While no differences in the proliferative capacity were identified, a general potential of MB in modulating the migratory capacity of adult neural stem cells was indicated in a cell mobility assay. To our knowledge, this is the first time that MB could be associated with neural mobility. The results of this study add insight to the spectrum of features of MB within the central nervous system and may be helpful for understanding the molecular mechanisms underlying a potential therapeutic effect of MB.
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Affiliation(s)
- Amelie T van der Ven
- Department of Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, LVR Hospital, Essen, Germany.,Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, MA, USA
| | | | - Dirk Hermann
- Department of Neurology, Chair of Vascular Neurology and Dementia, University Hospital of Essen, Germany
| | | | - Just Genius
- Department of Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, LVR Hospital, Essen, Germany
| | - Nadine Fischer
- Department of Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, LVR Hospital, Essen, Germany
| | - Rainald Mößner
- Department of Psychiatry, University of Tübingen, Germany
| | - Norbert Scherbaum
- Department of Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, LVR Hospital, Essen, Germany
| | - Jens Wiltfang
- Department of Psychiatry, University of Göttingen, Germany
| | - Dan Rujescu
- Department of Psychiatry and Psychotherapy, University of Halle (Saale), Germany
| | - Jens Benninghoff
- Department of Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, LVR Hospital, Essen, Germany
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Molecular Mechanisms in Perirhinal Cortex Selectively Necessary for Discrimination of Overlapping Memories, but Independent of Memory Persistence. eNeuro 2017; 4:eN-NWR-0293-17. [PMID: 29085903 PMCID: PMC5659266 DOI: 10.1523/eneuro.0293-17.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 09/06/2017] [Accepted: 09/11/2017] [Indexed: 12/02/2022] Open
Abstract
Successful memory involves not only remembering over time but also keeping memories distinct. The ability to separate similar experiences into distinct memories is a main feature of episodic memory. Discrimination of overlapping representations has been investigated in the dentate gyrus of the hippocampus (DG), but little is known about this process in other regions such as the perirhinal cortex (Prh). We found in male rats that perirhinal brain-derived neurotrophic factor (BDNF) is required for separable storage of overlapping, but not distinct, object representations, which is identical to its role in the DG for spatial representations. Also, activity-regulated cytoskeletal-associated protein (Arc) is required for disambiguation of object memories, as measured by infusion of antisense oligonucleotides. This is the first time Arc has been implicated in the discrimination of objects with overlapping features. Although molecular mechanisms for object memory have been shown previously in Prh, these have been dependent on delay, suggesting a role specifically in memory duration. BDNF and Arc involvement were independent of delay-the same demand for memory persistence was present in all conditions-but only when discrimination of similar objects was required were these mechanisms recruited and necessary. Finally, we show that BDNF and Arc participate in the same pathway during consolidation of overlapping object memories. We provide novel evidence regarding the proteins involved in disambiguation of object memories outside the DG and suggest that, despite the anatomical differences, similar mechanisms underlie this process in the DG and Prh that are engaged depending on the similarity of the stimuli.
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Birkel L. Decreased use of spatial pattern separation in contemporary lifestyles may contribute to hippocampal atrophy and diminish mental health. Med Hypotheses 2017; 107:55-63. [DOI: 10.1016/j.mehy.2017.07.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 07/14/2017] [Indexed: 10/19/2022]
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França TFA, Bitencourt AM, Maximilla NR, Barros DM, Monserrat JM. Hippocampal neurogenesis and pattern separation: A meta-analysis of behavioral data. Hippocampus 2017; 27:937-950. [PMID: 28597491 DOI: 10.1002/hipo.22746] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 05/09/2017] [Accepted: 05/26/2017] [Indexed: 12/16/2022]
Abstract
The generation of new neurons in the hippocampus of adult mammals has become a widely accepted phenomenon, but the functional significance of the adult neurogenesis in the hippocampus is not fully understood. One of the main hypotheses currently investigated suggests that neurogenesis contributes to pattern separation in the dentate gyrus. Many behavioral studies were conducted aiming to test this hypothesis using rodents as animal model. In those studies, researches ablated neurogenesis in the animals and subsequently evaluate them in tests of behavioral pattern separation, that is, behaviors that are thought to rely on the computational process of pattern separation. The results of these studies are varied, with most supporting a role for neurogenesis in pattern separation, but some others not. To address this controversy we performed a systematic review and meta-analysis of studies evaluating the effect of neurogenesis ablation on behavioral pattern separation. Analysis results indicated that most of the literature in the topic is surprisingly consistent and, although there are two studies with divergent results, the bulk of the literature supports an effect of hippocampal neurogenesis on behavioral pattern separation. We discuss those findings in light of other behavioral effects of hippocampal neurogenesis ablation, limitations of behavioral data and other lines of evidence about the effect of hippocampal neurogenesis in the dentate gyrus.
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Affiliation(s)
- Thiago F A França
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, Brazil
| | - Alexandre M Bitencourt
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, Brazil
| | - Naiana R Maximilla
- Curso de graduação em Ciências Biológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, Brazil
| | - Daniela M Barros
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, Brazil.,Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, Brazil
| | - José M Monserrat
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, Brazil.,Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, Brazil
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40
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Anacker C, Hen R. Adult hippocampal neurogenesis and cognitive flexibility - linking memory and mood. Nat Rev Neurosci 2017; 18:335-346. [PMID: 28469276 DOI: 10.1038/nrn.2017.45] [Citation(s) in RCA: 621] [Impact Index Per Article: 88.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Adult hippocampal neurogenesis has been implicated in cognitive processes, such as pattern separation, and in the behavioural effects of stress and antidepressants. Young adult-born neurons have been shown to inhibit the overall activity of the dentate gyrus by recruiting local interneurons, which may result in sparse contextual representations and improved pattern separation. We propose that neurogenesis-mediated inhibition also reduces memory interference and enables reversal learning both in neutral situations and in emotionally charged ones. Such improved cognitive flexibility may in turn help to decrease anxiety-like and depressive-like behaviour.
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Affiliation(s)
- Christoph Anacker
- Department of Psychiatry, Columbia University and Research Foundation for Mental Hygiene, New York State Psychiatric Institute, 1051 Riverside Drive, New York 10032, New York, USA
| | - René Hen
- Department of Psychiatry, Columbia University and Research Foundation for Mental Hygiene, New York State Psychiatric Institute, 1051 Riverside Drive, New York 10032, New York, USA.,Department of Neuroscience, Columbia University, Kolb Annex, 40 Haven Ave, New York 10032, New York, USA.,Department of Pharmacology, Columbia University, 630 West 168th Street, New York 10032, New York, USA
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41
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Glover LR, Schoenfeld TJ, Karlsson RM, Bannerman DM, Cameron HA. Ongoing neurogenesis in the adult dentate gyrus mediates behavioral responses to ambiguous threat cues. PLoS Biol 2017; 15:e2001154. [PMID: 28388632 PMCID: PMC5384657 DOI: 10.1371/journal.pbio.2001154] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 03/06/2017] [Indexed: 01/14/2023] Open
Abstract
Fear learning is highly adaptive if utilized in appropriate situations but can lead to generalized anxiety if applied too widely. A role of predictive cues in inhibiting fear generalization has been suggested by stress and fear learning studies, but the effects of partially predictive cues (ambiguous cues) and the neuronal populations responsible for linking the predictive ability of cues and generalization of fear responses are unknown. Here, we show that inhibition of adult neurogenesis in the mouse dentate gyrus decreases hippocampal network activation and reduces defensive behavior to ambiguous threat cues but has neither of these effects if the same negative experience is reliably predicted. Additionally, we find that this ambiguity related to negative events determines their effect on fear generalization, that is, how the events affect future behavior under novel conditions. Both new neurons and glucocorticoid hormones are required for the enhancement of fear generalization following an unpredictably cued threat. Thus, adult neurogenesis plays a central role in the adaptive changes resulting from experience involving unpredictable or ambiguous threat cues, optimizing behavior in novel and uncertain situations. The ability to predict whether an experience will end favorably is critical for well-being. Cues associated with specific outcomes can aid in prediction, enabling adaptive behaviors, but cue-outcome relationships are often difficult to learn or inherently ambiguous. Human studies have suggested that the hippocampus, a brain region involved in learning and memory, is also important for predicting outcomes and mediating behavior in situations of uncertainty and conflict. We tested the role of a subtype of hippocampal neurons born in adulthood in responding to ambiguously cued shock. We found that mice without these young neurons show less defensive behavior than normal mice when they hear an ambiguous cue, paired with shock in 50% of trials, but react normally when the cue perfectly predicts the shock. In a novel situation, normal mice behave defensively after ambiguously cued shocks but show very little anxiety-like (defensive) behavior if shocks were predictable. Mice without new neurons fail to make this adaptive change, showing moderate levels of anxiety-like behavior regardless of the predictability of earlier threats. Our findings suggest that an important role for the continued neurogenesis in the hippocampus is to enable adaptive changes to future behavior depending upon predictability of prior threats.
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Affiliation(s)
- Lucas R. Glover
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Timothy J. Schoenfeld
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Rose-Marie Karlsson
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America
| | - David M. Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Heather A. Cameron
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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42
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Hueston CM, Cryan JF, Nolan YM. Stress and adolescent hippocampal neurogenesis: diet and exercise as cognitive modulators. Transl Psychiatry 2017; 7:e1081. [PMID: 28375209 PMCID: PMC5416690 DOI: 10.1038/tp.2017.48] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 01/04/2017] [Accepted: 02/01/2017] [Indexed: 02/08/2023] Open
Abstract
Adolescence is a critical period for brain maturation. Deciphering how disturbances to the central nervous system at this time affect structure, function and behavioural outputs is important to better understand any long-lasting effects. Hippocampal neurogenesis occurs during development and continues throughout life. In adulthood, integration of these new cells into the hippocampus is important for emotional behaviour, cognitive function and neural plasticity. During the adolescent period, maturation of the hippocampus and heightened levels of hippocampal neurogenesis are observed, making alterations to neurogenesis at this time particularly consequential. As stress negatively affects hippocampal neurogenesis, and adolescence is a particularly stressful time of life, it is important to investigate the impact of stressor exposure at this time on hippocampal neurogenesis and cognitive function. Adolescence may represent not only a time for which stress can have long-lasting effects, but is also a critical period during which interventions, such as exercise and diet, could ameliorate stress-induced changes to hippocampal function. In addition, intervention at this time may also promote life-long behavioural changes that would aid in fostering increased hippocampal neurogenesis and cognitive function. This review addresses both the acute and long-term stress-induced alterations to hippocampal neurogenesis and cognition during the adolescent period, as well as changes to the stress response and pubertal hormones at this time which may result in differential effects than are observed in adulthood. We hypothesise that adolescence may represent an optimal time for healthy lifestyle changes to have a positive and long-lasting impact on hippocampal neurogenesis, and to protect against stress-induced deficits. We conclude that future research into the mechanisms underlying the susceptibility of the adolescent hippocampus to stress, exercise and diet and the consequent effect on cognition may provide insight into why adolescence may be a vital period for correct conditioning of future hippocampal function.
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Affiliation(s)
- C M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - J F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Y M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
- APC Microbiome Institute, University College Cork, Cork, Ireland
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Kent BA, Mistlberger RE. Sleep and hippocampal neurogenesis: Implications for Alzheimer's disease. Front Neuroendocrinol 2017; 45:35-52. [PMID: 28249715 DOI: 10.1016/j.yfrne.2017.02.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 01/23/2017] [Accepted: 02/24/2017] [Indexed: 01/29/2023]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia and currently there are no effective disease-modifying treatments available. Hallmark symptoms of AD include impaired hippocampus-dependent episodic memory and disrupted sleep and circadian rhythms. The pathways connecting these symptoms are of particular interest because it is well established that sleep and circadian disruption can impair hippocampus-dependent learning and memory. In rodents, these procedures also markedly suppress adult hippocampal neurogenesis, a form of brain plasticity that is believed to play an important role in pattern separation, and thus episodic memory. A causal role for sleep disruptions in AD pathophysiology is suggested by evidence for sleep-dependent glymphatic clearance of metabolic waste products from the brain. This review explores a complementary hypothesis that sleep and circadian disruptions in AD contribute to cognitive decline by activating neuroendocrine and neuroinflammatory signaling pathways that suppress hippocampal neurogenesis. Evidence for this hypothesis underscores the promise of sleep, circadian rhythms, and neurogenesis as therapeutic targets for remediation of memory impairment in AD.
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Affiliation(s)
- Brianne A Kent
- Division of Neurology and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
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Haploinsufficiency of EHMT1 improves pattern separation and increases hippocampal cell proliferation. Sci Rep 2017; 7:40284. [PMID: 28071689 PMCID: PMC5223204 DOI: 10.1038/srep40284] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 12/02/2016] [Indexed: 12/22/2022] Open
Abstract
Heterozygous mutations or deletions of the human Euchromatin Histone Methyltransferase 1 (EHMT1) gene are the main causes of Kleefstra syndrome, a neurodevelopmental disorder that is characterized by impaired memory, autistic features and mostly severe intellectual disability. Previously, Ehmt1+/− heterozygous knockout mice were found to exhibit cranial abnormalities and decreased sociability, phenotypes similar to those observed in Kleefstra syndrome patients. In addition, Ehmt1+/− knockout mice were impaired at fear extinction and novel- and spatial object recognition. In this study, Ehmt1+/− and wild-type mice were tested on several cognitive tests in a touchscreen-equipped operant chamber to further investigate the nature of learning and memory changes. Performance of Ehmt1+/− mice in the Visual Discrimination & Reversal learning, object-location Paired-Associates learning- and Extinction learning tasks was found to be unimpaired. Remarkably, Ehmt1+/− mice showed enhanced performance on the Location Discrimination test of pattern separation. In line with improved Location Discrimination ability, an increase in BrdU-labelled cells in the subgranular zone of the dentate gyrus was observed. In conclusion, reduced levels of EHMT1 protein in Ehmt1+/− mice does not result in general learning deficits in a touchscreen-based battery, but leads to increased adult cell proliferation in the hippocampus and enhanced pattern separation ability.
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Chauhan G, Ray K, Sahu S, Roy K, Jain V, Wadhwa M, Panjwani U, Kishore K, Singh S. Adenosine A1 receptor antagonist mitigates deleterious effects of sleep deprivation on adult neurogenesis and spatial reference memory in rats. Neuroscience 2016; 337:107-116. [DOI: 10.1016/j.neuroscience.2016.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 08/30/2016] [Accepted: 09/05/2016] [Indexed: 01/19/2023]
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Kandola A, Hendrikse J, Lucassen PJ, Yücel M. Aerobic Exercise as a Tool to Improve Hippocampal Plasticity and Function in Humans: Practical Implications for Mental Health Treatment. Front Hum Neurosci 2016; 10:373. [PMID: 27524962 PMCID: PMC4965462 DOI: 10.3389/fnhum.2016.00373] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 07/11/2016] [Indexed: 12/24/2022] Open
Abstract
Aerobic exercise (AE) has been widely praised for its potential benefits to cognition and overall brain and mental health. In particular, AE has a potent impact on promoting the function of the hippocampus and stimulating neuroplasticity. As the evidence-base rapidly builds, and given most of the supporting work can be readily translated from animal models to humans, the potential for AE to be applied as a therapeutic or adjunctive intervention for a range of human conditions appears ever more promising. Notably, many psychiatric and neurological disorders have been associated with hippocampal dysfunction, which may underlie the expression of certain symptoms common to these disorders, including (aspects of) cognitive dysfunction. Augmenting existing treatment approaches using AE based interventions may promote hippocampal function and alleviate cognitive deficits in various psychiatric disorders that currently remain untreated. Incorporating non-pharmacological interventions into clinical treatment may also have a number of other benefits to patient well being, such as limiting the risk of adverse side effects. This review incorporates both animal and human literature to comprehensively detail how AE is associated with cognitive enhancements and stimulates a cascade of neuroplastic mechanisms that support improvements in hippocampal functioning. Using the examples of schizophrenia and major depressive disorder, the utility and implementation of an AE intervention to the clinical domain will be proposed, aimed to reduce cognitive deficits in these, and related disorders.
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Affiliation(s)
- Aaron Kandola
- Brain and Mental Health Lab, School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, MelbourneVIC, Australia; Amsterdam Brain and Cognition, University of AmsterdamAmsterdam, Netherlands
| | - Joshua Hendrikse
- Brain and Mental Health Lab, School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne VIC, Australia
| | - Paul J Lucassen
- Centre for Neuroscience, Swammerdam Institute of Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Murat Yücel
- Brain and Mental Health Lab, School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne VIC, Australia
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Welbat JU, Chaisawang P, Chaijaroonkhanarak W, Prachaney P, Pannangrong W, Sripanidkulchai B, Wigmore P. Kaempferia parviflora extract ameliorates the cognitive impairments and the reduction in cell proliferation induced by valproic acid treatment in rats. Ann Anat 2016; 206:7-13. [DOI: 10.1016/j.aanat.2016.04.029] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 04/11/2016] [Accepted: 04/15/2016] [Indexed: 12/30/2022]
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49
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Adult neurogenesis and pattern separation in rodents: A critical evaluation of data, tasks and interpretation. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s11515-016-1406-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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50
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Reichelt AC, Morris MJ, Westbrook RF. Daily access to sucrose impairs aspects of spatial memory tasks reliant on pattern separation and neural proliferation in rats. ACTA ACUST UNITED AC 2016; 23:386-90. [PMID: 27317199 PMCID: PMC4918785 DOI: 10.1101/lm.042416.116] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 04/27/2016] [Indexed: 11/24/2022]
Abstract
High sugar diets reduce hippocampal neurogenesis, which is required for minimizing interference between memories, a process that involves “pattern separation.” We provided rats with 2 h daily access to a sucrose solution for 28 d and assessed their performance on a spatial memory task. Sucrose consuming rats discriminated between objects in novel and familiar locations when there was a large spatial separation between the objects, but not when the separation was smaller. Neuroproliferation markers in the dentate gyrus of the sucrose-consuming rats were reduced relative to controls. Thus, sucrose consumption impaired aspects of spatial memory and reduced hippocampal neuroproliferation.
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Affiliation(s)
- Amy C Reichelt
- School of Psychology, UNSW Australia, UNSW Sydney, New South Wales 2052, Australia
| | - Margaret J Morris
- School of Medical Sciences, UNSW Australia, UNSW Sydney, New South Wales 2052, Australia
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