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Maheshwari M, Singla A, Rawat A, Banerjee T, Pati S, Shah S, Maiti S, Vaidya VA. Chronic chemogenetic activation of hippocampal progenitors enhances adult neurogenesis and modulates anxiety-like behavior and fear extinction learning. IBRO Neurosci Rep 2024; 16:168-181. [PMID: 39007086 PMCID: PMC11240292 DOI: 10.1016/j.ibneur.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 01/18/2024] [Indexed: 07/16/2024] Open
Abstract
Adult hippocampal neurogenesis is a lifelong process that involves the integration of newborn neurons into the hippocampal network, and plays a role in cognitive function and the modulation of mood-related behavior. Here, we sought to address the impact of chemogenetic activation of adult hippocampal progenitors on distinct stages of progenitor development, including quiescent stem cell activation, progenitor turnover, differentiation and morphological maturation. We find that hM3Dq-DREADD-mediated activation of nestin-positive adult hippocampal progenitors recruits quiescent stem cells, enhances progenitor proliferation, increases doublecortin-positive newborn neuron number, accompanied by an acceleration of differentiation and morphological maturation, associated with increased dendritic complexity. Behavioral analysis indicated anxiolytic behavioral responses in transgenic mice subjected to chemogenetic activation of adult hippocampal progenitors at timepoints when newborn neurons are predicted to integrate into the mature hippocampal network. Furthermore, we noted an enhanced fear memory extinction on a contextual fear memory learning task in transgenic mice subjected to chemogenetic activation of adult hippocampal progenitors. Our findings indicate that hM3Dq-DREAD-mediated chemogenetic activation of adult hippocampal progenitors impacts distinct aspects of hippocampal neurogenesis, associated with the regulation of anxiety-like behavior and fear memory extinction.
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Affiliation(s)
| | | | - Anoop Rawat
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Toshali Banerjee
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Sthitapranjya Pati
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Sneha Shah
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Sudipta Maiti
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Vidita A. Vaidya
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
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Park EH, Jo YS, Kim EJ, Park EH, Lee KJ, Rhyu IJ, Kim HT, Choi JS. Heterogenous effect of early adulthood stress on cognitive aging and synaptic function in the dentate gyrus. Front Mol Neurosci 2024; 17:1344141. [PMID: 38638601 PMCID: PMC11024304 DOI: 10.3389/fnmol.2024.1344141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 02/29/2024] [Indexed: 04/20/2024] Open
Abstract
Cognitive aging widely varies among individuals due to different stress experiences throughout the lifespan and vulnerability of neurocognitive mechanisms. To understand the heterogeneity of cognitive aging, we investigated the effect of early adulthood stress (EAS) on three different hippocampus-dependent memory tasks: the novel object recognition test (assessing recognition memory: RM), the paired association test (assessing episodic-like memory: EM), and trace fear conditioning (assessing trace memory: TM). Two-month-old rats were exposed to chronic mild stress for 6 weeks and underwent behavioral testing either 2 weeks or 20 months later. The results show that stress and aging impaired different types of memory tasks to varying degrees. RM is affected by combined effect of stress and aging. EM became less precise in EAS animals. TM, especially the contextual memory, showed impairment in aging although EAS attenuated the aging effect, perhaps due to its engagement in emotional memory systems. To further explore the neural underpinnings of these multi-faceted effects, we measured long-term potentiation (LTP), neural density, and synaptic density in the dentate gyrus (DG). Both stress and aging reduced LTP. Additionally, the synaptic density per neuron showed a further reduction in the stress aged group. In summary, EAS modulates different forms of memory functions perhaps due to their substantial or partial dependence on the functional integrity of the hippocampus. The current results suggest that lasting alterations in hippocampal circuits following EAS could potentially generate remote effects on individual variability in cognitive aging, as demonstrated by performance in multiple types of memory.
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Affiliation(s)
- Eun Hye Park
- School of Psychology, Korea University, Seoul, Republic of Korea
- Department of Psychology, New York University, New York, NY, United States
| | - Yong Sang Jo
- School of Psychology, Korea University, Seoul, Republic of Korea
| | - Eun Joo Kim
- School of Psychology, Korea University, Seoul, Republic of Korea
- Department of Psychology, University of Washington, Seattle, WA, United States
| | - Eui Ho Park
- Department of Anatomy, Korea University College of Medicine, Seoul, Republic of Korea
| | - Kea Joo Lee
- Department of Structure and Function of Neural Network, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Im Joo Rhyu
- Department of Anatomy, Korea University College of Medicine, Seoul, Republic of Korea
| | - Hyun Taek Kim
- School of Psychology, Korea University, Seoul, Republic of Korea
| | - June-Seek Choi
- School of Psychology, Korea University, Seoul, Republic of Korea
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Mabry S, Wilson EN, Bradshaw JL, Gardner JJ, Fadeyibi O, Vera E, Osikoya O, Cushen SC, Karamichos D, Goulopoulou S, Cunningham RL. Sex and age differences in social and cognitive function in offspring exposed to late gestational hypoxia. Biol Sex Differ 2023; 14:81. [PMID: 37951901 PMCID: PMC10640736 DOI: 10.1186/s13293-023-00557-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 10/09/2023] [Indexed: 11/14/2023] Open
Abstract
BACKGROUND Gestational sleep apnea is a hypoxic sleep disorder that affects 8-26% of pregnancies and increases the risk for central nervous system dysfunction in offspring. Specifically, there are sex differences in the sensitivity of the fetal hippocampus to hypoxic insults, and hippocampal impairments are associated with social dysfunction, repetitive behaviors, anxiety, and cognitive impairment. Yet, it is unclear whether gestational sleep apnea impacts these hippocampal-associated functions and if sex and age modify these effects. To examine the relationship between gestational sleep apnea and hippocampal-associated behaviors, we used chronic intermittent hypoxia (CIH) to model late gestational sleep apnea in pregnant rats. We hypothesized that late gestational CIH would produce sex- and age-specific social, anxiety-like, repetitive, and cognitive impairments in offspring. METHODS Timed pregnant Long-Evans rats were exposed to CIH or room air normoxia from GD 15-19. Behavioral testing of offspring occurred during either puberty or young adulthood. To examine gestational hypoxia-induced behavioral phenotypes, we quantified hippocampal-associated behaviors (social function, repetitive behaviors, anxiety-like behaviors, and spatial memory and learning), hippocampal neuronal activity (glutamatergic NMDA receptors, dopamine transporter, monoamine oxidase-A, early growth response protein 1, and doublecortin), and circulating hormones in offspring. RESULTS Late gestational CIH induced sex- and age-specific differences in social, repetitive, and memory functions in offspring. In female pubertal offspring, CIH impaired social function, increased repetitive behaviors, and elevated circulating corticosterone levels but did not impact memory. In contrast, CIH transiently induced spatial memory dysfunction in pubertal male offspring but did not impact social or repetitive functions. Long-term effects of gestational CIH on social behaviors were only observed in female offspring, wherein CIH induced social disengagement and suppression of circulating corticosterone levels in young adulthood. No effects of gestational CIH were observed in anxiety-like behaviors, hippocampal neuronal activity, or circulating testosterone and estradiol levels, regardless of sex or age of offspring. CONCLUSIONS Our results indicate that hypoxia-associated pregnancy complications during late gestation can increase the risk for behavioral and physiological outcomes in offspring, such as social dysfunction, repetitive behaviors, and cognitive impairment, that are dependent on sex and age.
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Affiliation(s)
- Steve Mabry
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - E Nicole Wilson
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Jessica L Bradshaw
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Jennifer J Gardner
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Oluwadarasimi Fadeyibi
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Edward Vera
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Oluwatobiloba Osikoya
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Spencer C Cushen
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Dimitrios Karamichos
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
- Department of Pharmacology and Neuroscience, University of North Texas Health Science, Fort Worth, TX, 76107, USA
| | - Styliani Goulopoulou
- Departments of Basic Sciences, Gynecology and Obstetrics, Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA.
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Silvas-Baltazar M, López-Oropeza G, Durán P, Martínez-Canabal A. Olfactory neurogenesis and its role in fear memory modulation. Front Behav Neurosci 2023; 17:1278324. [PMID: 37840547 PMCID: PMC10569173 DOI: 10.3389/fnbeh.2023.1278324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 09/12/2023] [Indexed: 10/17/2023] Open
Abstract
Olfaction is a critical sense that allows animals to navigate and understand their environment. In mammals, the critical brain structure to receive and process olfactory information is the olfactory bulb, a structure characterized by a laminated pattern with different types of neurons, some of which project to distant telencephalic structures, like the piriform cortex, the amygdala, and the hippocampal formation. Therefore, the olfactory bulb is the first structure of a complex cognitive network that relates olfaction to different types of memory, including episodic memories. The olfactory bulb continuously adds inhibitory newborn neurons throughout life; these cells locate both in the granule and glomerular layers and integrate into the olfactory circuits, inhibiting projection neurons. However, the roles of these cells modulating olfactory memories are unclear, particularly their role in fear memories. We consider that olfactory neurogenesis might modulate olfactory fear memories by a plastic process occurring in the olfactory bulb.
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Affiliation(s)
- Monserrat Silvas-Baltazar
- Licenciatura en Neurociencias, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Grecia López-Oropeza
- Licenciatura en Neurociencias, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Posgrado en Ciencias Biológicas, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Pilar Durán
- Licenciatura en Neurociencias, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Posgrado en Ciencias Biológicas, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Alonso Martínez-Canabal
- Licenciatura en Neurociencias, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Posgrado en Ciencias Biológicas, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
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Mabry S, Wilson EN, Bradshaw JL, Gardner JJ, Fadeyibi O, Vera E, Osikoya O, Cushen SC, Karamichos D, Goulopoulou S, Cunningham RL. Sex and age differences in social and cognitive function in offspring exposed to late gestational hypoxia. RESEARCH SQUARE 2023:rs.3.rs-2507737. [PMID: 37333114 PMCID: PMC10275064 DOI: 10.21203/rs.3.rs-2507737/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Background Gestational sleep apnea affects 8-26% of pregnancies and can increase the risk for autism spectrum disorder (ASD) in offspring. ASD is a neurodevelopmental disorder associated with social dysfunction, repetitive behaviors, anxiety, and cognitive impairment. To examine the relationship between gestational sleep apnea and ASD-associated behaviors, we used a chronic intermittent hypoxia (CIH) protocol between gestational days (GD) 15-19 in pregnant rats to model late gestational sleep apnea. We hypothesized that late gestational CIH would produce sex- and age-specific social, mood, and cognitive impairments in offspring. Methods Timed pregnant Long-Evans rats were exposed to CIH or room air normoxia from GD 15-19. Behavioral testing of offspring occurred during either puberty or young adulthood. To examine ASD-associated phenotypes, we quantified ASD-associated behaviors (social function, repetitive behaviors, anxiety-like behaviors, and spatial memory and learning), hippocampal activity (glutamatergic NMDA receptors, dopamine transporter, monoamine oxidase-A, EGR-1, and doublecortin), and circulating hormones in offspring. Results Late gestational CIH induced sex- and age-specific differences in social, repetitive and memory functions in offspring. These effects were mostly transient and present during puberty. In female pubertal offspring, CIH impaired social function, increased repetitive behaviors, and increased circulating corticosterone levels, but did not impact memory. In contrast, CIH transiently induced spatial memory dysfunction in pubertal male offspring but did not impact social or repetitive functions. Long-term effects of gestational CIH were only observed in female offspring, wherein CIH induced social disengagement and suppression of circulating corticosterone levels in young adulthood. No effects of gestational CIH were observed on anxiety-like behaviors, hippocampal activity, circulating testosterone levels, or circulating estradiol levels, regardless of sex or age of offspring. Conclusions Our results indicate that hypoxia-associated pregnancy complications during late gestation can increase the risk for ASD-associated behavioral and physiological outcomes, such as pubertal social dysfunction, corticosterone dysregulation, and memory impairments.
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Affiliation(s)
- Steve Mabry
- UNTHSC: University of North Texas Health Science Center
| | | | | | | | | | - Edward Vera
- UNTHSC: University of North Texas Health Science Center
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Abazari D, Wild AR, Qiu T, Dickinson BC, Bamji SX. Activity-dependent post-translational regulation of palmitoylating and depalmitoylating enzymes in the hippocampus. J Cell Sci 2023; 136:jcs260629. [PMID: 37039765 PMCID: PMC10113885 DOI: 10.1242/jcs.260629] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 01/20/2023] [Indexed: 04/12/2023] Open
Abstract
Activity-induced changes in protein palmitoylation can regulate the plasticity of synaptic connections, critically impacting learning and memory. Palmitoylation is a reversible post-translational modification regulated by both palmitoyl-acyl transferases that mediate palmitoylation and palmitoyl thioesterases that depalmitoylate proteins. However, it is not clear how fluctuations in synaptic activity can mediate the dynamic palmitoylation of neuronal proteins. Using primary hippocampal cultures, we demonstrate that synaptic activity does not impact the transcription of palmitoylating and depalmitoylating enzymes, changes in thioesterase activity, or post-translational modification of the depalmitoylating enzymes of the ABHD17 family and APT2 (also known as LYPLA2). In contrast, synaptic activity does mediate post-translational modification of the palmitoylating enzymes ZDHHC2, ZDHHC5 and ZDHHC9 (but not ZDHHC8) to influence protein-protein interactions, enzyme stability and enzyme function. Post-translational modifications of the ZDHHC enzymes were also observed in the hippocampus following fear conditioning. Taken together, our findings demonstrate that signaling events activated by synaptic activity largely impact activity of the ZDHHC family of palmitoyl-acyl transferases with less influence on the activity of palmitoyl thioesterases.
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Affiliation(s)
- Danya Abazari
- Department of Cellular and Physiological Sciences, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Angela R. Wild
- Department of Cellular and Physiological Sciences, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Tian Qiu
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
| | | | - Shernaz X. Bamji
- Department of Cellular and Physiological Sciences, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
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Aberrant ventral dentate gyrus structure and function in trauma susceptible mice. Transl Psychiatry 2022; 12:502. [PMID: 36473832 PMCID: PMC9723770 DOI: 10.1038/s41398-022-02264-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 12/12/2022] Open
Abstract
Post-traumatic stress disorder (PTSD) is a psychiatric disorder vulnerable individuals can develop following a traumatic event, whereas others are resilient. Enhanced insight into the mechanistic underpinnings contributing to these inter-individual differences in trauma susceptibility is key to improved treatment and prevention. Aberrant function of the hippocampal dentate gyrus (DG) may contribute to its psychopathology, with the dorsal DG potentially encoding trauma memory generalization and the ventral DG anxiety. Using a mouse model, we hypothesized that susceptibility to develop PTSD-like symptoms following trauma will be underpinned by aberrant DG structure and function. Mice were exposed to a traumatic event (unpredictable, inescapable foot shocks) and tested for PTSD-like symptomatology following recovery. In four independent experiments, DG neuronal morphology, synaptic protein gene and protein expression, and neuronal activity during trauma encoding and recall were assessed. Behaviorally, trauma-susceptible animals displayed increased anxiety-like behavior already prior to trauma, increased novelty-induced freezing, but no clear differences in remote trauma memory recall. Comparison of the ventral DG of trauma susceptible vs resilient mice revealed lower spine density, reduced expression of the postsynaptic protein homer1b/c gene and protein, a larger population of neurons active during trauma encoding, and a greater presence of somatostatin neurons. In contrast, the dorsal DG of trauma-susceptible animals did not differ in terms of spine density or gene expression but displayed more active neurons during trauma encoding and a lower amount of somatostatin neurons. Collectively, we here report on specific structural and functional changes in the ventral DG in trauma susceptible male mice.
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Nasseri GG, Matin N, Wild AR, Tosefsky K, Flibotte S, Stacey RG, Hollman RB, Foster LJ, Bamji SX. Synaptic activity-dependent changes in the hippocampal palmitoylome. Sci Signal 2022; 15:eadd2519. [PMID: 36473050 DOI: 10.1126/scisignal.add2519] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dynamic protein S-palmitoylation is critical for neuronal function, development, and synaptic plasticity. Synaptic activity-dependent changes in palmitoylation have been reported for a small number of proteins. Here, we characterized the palmitoylome in the hippocampi of male mice before and after context-dependent fear conditioning. Of the 121 differentially palmitoylated proteins identified, just over half were synaptic proteins, whereas others were associated with metabolic functions, cytoskeletal organization, and signal transduction. The synapse-associated proteins generally exhibited increased palmitoylation after fear conditioning. In contrast, most of the proteins that exhibited decreased palmitoylation were associated with metabolic processes. Similar results were seen in cultured rat hippocampal neurons in response to chemically induced long-term potentiation. Furthermore, we found that the palmitoylation of one of the synaptic proteins, plasticity-related gene-1 (PRG-1), also known as lipid phosphate phosphatase-related protein type 4 (LPPR4), was important for synaptic activity-induced insertion of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) into the postsynaptic membrane. The findings identify proteins whose dynamic palmitoylation may regulate their role in synaptic plasticity, learning, and memory.
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Affiliation(s)
- Glory G Nasseri
- Department of Cellular and Physiological Sciences, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Nusrat Matin
- Department of Cellular and Physiological Sciences, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Angela R Wild
- Department of Cellular and Physiological Sciences, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Kira Tosefsky
- Department of Cellular and Physiological Sciences, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Stephane Flibotte
- Life Sciences Institute Bioinformatics Facility, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - R Greg Stacey
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Rocio B Hollman
- Department of Cellular and Physiological Sciences, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Leonard J Foster
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Shernaz X Bamji
- Department of Cellular and Physiological Sciences, Life Sciences Institute and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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Nishimura KJ, Poulos A, Drew MR, Rajbhandari AK. Know thy SEFL: Fear sensitization and its relevance to stressor-related disorders. Neurosci Biobehav Rev 2022; 142:104884. [PMID: 36174795 DOI: 10.1016/j.neubiorev.2022.104884] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/07/2022] [Accepted: 09/17/2022] [Indexed: 11/27/2022]
Abstract
Extreme stress can cause long-lasting changes in affective behavior manifesting in conditions such as post-traumatic stress disorder (PTSD). Understanding the biological mechanisms that govern trauma-induced behavioral dysregulation requires reliable and rigorous pre-clinical models that recapitulate multiple facets of this complex disease. For decades, Pavlovian fear conditioning has been a dominant paradigm for studying the effects of trauma through an associative learning framework. However, severe stress also causes long-lasting nonassociative fear sensitization, which is often overlooked in Pavlovian fear conditioning studies. This paper synthesizes recent research on the stress-enhanced fear learning (SEFL) paradigm, a valuable rodent model that can dissociate associative and nonassociative effects of stress. We discuss evidence that the SEFL paradigm produces nonassociative fear sensitization that is distinguishable from Pavlovian fear conditioning. We also discuss key biological variables, such as age and sex, neural circuit mechanisms, and crucial gaps in knowledge. We argue that nonassociative fear sensitization deserves more attention within current PTSD models and that SEFL provides a valuable complement to Pavlovian conditioning research on trauma-related pathology.
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Affiliation(s)
- Kenji J Nishimura
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, USA, 78712
| | - Andrew Poulos
- Department of Psychology and Center for Neuroscience Research, State University of New York at Albany, Albany, USA, 12222
| | - Michael R Drew
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, USA, 78712
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Pak S, Choi G, Roy J, Poon CH, Lee J, Cho D, Lee M, Lim LW, Bao S, Yang S, Yang S. Altered synaptic plasticity of the longitudinal dentate gyrus network in noise-induced anxiety. iScience 2022; 25:104364. [PMID: 35620435 PMCID: PMC9127171 DOI: 10.1016/j.isci.2022.104364] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 01/31/2022] [Accepted: 05/03/2022] [Indexed: 12/20/2022] Open
Abstract
Anxiety is characteristic comorbidity of noise-induced hearing loss (NIHL), which causes physiological changes within the dentate gyrus (DG), a subfield of the hippocampus that modulates anxiety. However, which DG circuit underlies hearing loss-induced anxiety remains unknown. We utilize an NIHL mouse model to investigate short- and long-term synaptic plasticity in DG networks. The recently discovered longitudinal DG-DG network is a collateral of DG neurons synaptically connected with neighboring DG neurons and displays robust synaptic efficacy and plasticity. Furthermore, animals with NIHL demonstrate increased anxiety-like behaviors similar to a response to chronic restraint stress. These behaviors are concurrent with enhanced synaptic responsiveness and suppressed short- and long-term synaptic plasticity in the longitudinal DG-DG network but not in the transverse DG-CA3 connection. These findings suggest that DG-related anxiety is typified by synaptic alteration in the longitudinal DG-DG network. Traumatic noise-induced hearing loss enhances anxiety-like behaviors The longitudinal DG-DG network displays robust synaptic efficacy and plasticity Abnormal anxiety is associated with synaptic alterations of the DG-DG network DG-related brain disorders might stem from dysfunctional DG-DG networks
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Anxiety and hippocampal neuronal activity: Relationship and potential mechanisms. COGNITIVE, AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2022; 22:431-449. [PMID: 34873665 DOI: 10.3758/s13415-021-00973-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/11/2021] [Indexed: 12/15/2022]
Abstract
The hippocampus has been implicated in modulating anxiety. It interacts with a variety of brain regions, both cortical and subcortical areas regulating emotion and stress responses, including prefrontal cortex, amygdala, hypothalamus, and the nucleus accumbens, to adjust anxiety levels in response to a variety of stressful conditions. Growing evidence indicates that anxiety is associated with increased neuronal excitability in the hippocampus, and alterations in local regulation of hippocampal excitability have been suggested to underlie behavioral disruptions characteristic of certain anxiety disorders. Furthermore, studies have shown that some anxiolytics can treat anxiety by altering the excitability and plasticity of hippocampal neurons. Hence, identifying cellular and molecular mechanisms and neural circuits that regulate hippocampal excitability in anxiety may be beneficial for developing targeted interventions for treatment of anxiety disorders particularly for the treatment-resistant cases. We first briefly review a role of the hippocampus in fear. We then review the evidence indicating a relationship between the hippocampal activity and fear/anxiety and discuss some possible mechanisms underlying stress-induced hippocampal excitability and anxiety-related behavior.
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Austin R, Chander P, Zimmerman AJ, Overby M, Digilio L, Yap CC, Linsenbardt DN, Müller HK, Weick JP. Global loss of Neuron-specific gene 1 causes alterations in motor coordination, increased anxiety, and diurnal hyperactivity in male mice. GENES, BRAIN, AND BEHAVIOR 2022; 21:e12816. [PMID: 35577358 PMCID: PMC9262855 DOI: 10.1111/gbb.12816] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 11/26/2022]
Abstract
The Neuron-specific gene family (NSG1-3) consists of small endolysosomal proteins that are critical for trafficking multiple receptors and signaling molecules in neurons. NSG1 has been shown to play a critical role in AMPAR recycling from endosomes to plasma membrane during synaptic plasticity. However, to date nothing is known about whether NSG1 is required for normal behavior at an organismal level. Here we performed a battery of behavioral tests to determine whether loss of NSG1 would affect motor, cognitive, and/or affective behaviors, as well as circadian-related activity. Consistent with unique cerebellar expression of NSG1 among family members, we found that NSG1 was obligatory for motor coordination but not for gross motor function or learning. NSG1 knockout (KO) also altered performance across other behavioral modalities including anxiety-related and diurnal activity paradigms. Surprisingly, NSG1 KO did not cause significant impairments across all tasks within a given modality, but had specific effects within each modality. For instance, we found increases in anxiety-related behaviors in tasks with multiple stressors (e.g., elevation and exposure), but not those with a single main stressor (e.g., exposure). Interestingly, NSG1 KO animals displayed a significant increase in locomotor activity during subjective daytime, suggesting a possible impact on diurnal activity rhythms or vigilance. Surprisingly, loss of NSG1 had no effect on hippocampal-dependent learning despite previous studies showing deficits in CA1 long-term potentiation. Together, these findings do not support a role of NSG1 in hippocampal-dependent learning, but support a role in mediating proper neuronal function across amygdalar and cerebellar circuits.
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Affiliation(s)
- Roman Austin
- Department of NeurosciencesUniversity of New Mexico School of MedicineAlbuquerqueNew MexicoUSA
| | - Praveen Chander
- Department of NeurosciencesUniversity of New Mexico School of MedicineAlbuquerqueNew MexicoUSA
| | - Amber J. Zimmerman
- Department of NeurosciencesUniversity of New Mexico School of MedicineAlbuquerqueNew MexicoUSA
| | - Malene Overby
- Department of Clinical Medicine, Translational Neuropsychiatry UnitAarhus UniversityAarhus CDenmark
| | - Laura Digilio
- Department of Cell BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Chan Choo Yap
- Department of Cell BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - David N. Linsenbardt
- Department of NeurosciencesUniversity of New Mexico School of MedicineAlbuquerqueNew MexicoUSA
| | - Heidi Kaastrup Müller
- Department of Clinical Medicine, Translational Neuropsychiatry UnitAarhus UniversityAarhus CDenmark
| | - Jason P. Weick
- Department of NeurosciencesUniversity of New Mexico School of MedicineAlbuquerqueNew MexicoUSA
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13
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Sex Differences in the Spatial Behavior Functions of Adult-Born Neurons in Rats. eNeuro 2022; 9:ENEURO.0054-22.2022. [PMID: 35473765 PMCID: PMC9116935 DOI: 10.1523/eneuro.0054-22.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/13/2022] [Accepted: 04/15/2022] [Indexed: 01/04/2023] Open
Abstract
Adult neurogenesis modifies hippocampal circuits and behavior, but removing newborn neurons does not consistently alter spatial processing, a core function of the hippocampus. Additionally, little is known about sex differences in neurogenesis since few studies have compared males and females. Since adult-born neurons regulate the stress response, we hypothesized that spatial functions may be more prominent under aversive conditions and may differ between males and females given sex differences in stress responding. We therefore trained intact and neurogenesis-deficient rats in the spatial water maze at temperatures that vary in their degree of aversiveness. In the standard water maze, ablating neurogenesis did not alter spatial learning in either sex. However, in cold water, ablating neurogenesis had divergent sex-dependent effects: relative to intact rats, male neurogenesis-deficient rats were slower to escape the maze and female neurogenesis-deficient rats were faster. Neurogenesis promoted temperature-related changes in search strategy in females, but it promoted search strategy stability in males. Females displayed greater recruitment (Fos expression) of the dorsal hippocampus than males, particularly in cold water. However, blocking neurogenesis did not alter Fos expression in either sex. Finally, morphologic analyses revealed greater experience-dependent plasticity in males. Adult-born neurons in males and females had similar morphology at baseline but training increased spine density and reduced presynaptic terminal size, specifically in males. Collectively, these findings indicate that adult-born neurons contribute to spatial learning in stressful conditions and they provide new evidence for sex differences in their behavioral functions.
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14
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Gourmaud S, Stewart DA, Irwin DJ, Roberts N, Barbour AJ, Eberwine G, O’Brien WT, Vassar R, Talos DM, Jensen FE. The role of mTORC1 activation in seizure-induced exacerbation of Alzheimer's disease. Brain 2022; 145:324-339. [PMID: 34264340 PMCID: PMC9126019 DOI: 10.1093/brain/awab268] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/04/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
The risk of seizures is 10-fold higher in patients with Alzheimer's disease than the general population, yet the mechanisms underlying this susceptibility and the effects of these seizures are poorly understood. To elucidate the proposed bidirectional relationship between Alzheimer's disease and seizures, we studied human brain samples (n = 34) from patients with Alzheimer's disease and found that those with a history of seizures (n = 14) had increased amyloid-β and tau pathology, with upregulation of the mechanistic target of rapamycin (mTOR) pathway, compared with patients without a known history of seizures (n = 20). To establish whether seizures accelerate the progression of Alzheimer's disease, we induced chronic hyperexcitability in the five times familial Alzheimer's disease mouse model by kindling with the chemoconvulsant pentylenetetrazol and observed that the mouse model exhibited more severe seizures than the wild-type. Furthermore, kindled seizures exacerbated later cognitive impairment, Alzheimer's disease neuropathology and mTOR complex 1 activation. Finally, we demonstrated that the administration of the mTOR inhibitor rapamycin following kindled seizures rescued enhanced remote and long-term memory deficits associated with earlier kindling and prevented seizure-induced increases in Alzheimer's disease neuropathology. These data demonstrated an important link between chronic hyperexcitability and progressive Alzheimer's disease pathology and suggest a mechanism whereby rapamycin may serve as an adjunct therapy to attenuate progression of the disease.
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Affiliation(s)
- Sarah Gourmaud
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David A Stewart
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Duke University School of Medicine, Durham, NC 27708, USA
| | - David J Irwin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Penn Frontotemporal Degeneration Center, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicholas Roberts
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Aaron J Barbour
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Grace Eberwine
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William T O’Brien
- Neurobehavior Testing Core, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert Vassar
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Delia M Talos
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Frances E Jensen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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15
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Tripathi S, Jha SK. REM Sleep Deprivation Alters Learning-Induced Cell Proliferation and Generation of Newborn Young Neurons in the Dentate Gyrus of the Dorsal Hippocampus. ACS Chem Neurosci 2022; 13:194-206. [PMID: 34990120 DOI: 10.1021/acschemneuro.1c00465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The hippocampus-dependent "trace-appetitive conditioning task" increases cell proliferation and the generation of newborn young neurons. Evidence suggests that adult hippocampal neurogenesis and rapid eye movement (REM) sleep play an essential role in memory consolidation. On the other hand, REM sleep deprivation (REM-SD) induces detrimental effects on training-induced cell proliferation in the hippocampus's dentate gyrus (DG). Nonetheless, the role of REM sleep in the trace-appetitive memory and fate determination of the newly proliferated cells is not known. Here, we have studied the following: (I) the effects of 24 h of REM-SD (soon after training) on trace- and delay-appetitive memory and cell proliferation in the adult DG and (II) the effects of chronic (96 h) REM-SD (3 days after the training, the period in which newly generated cells progressed toward the neuronal lineage) on trace-appetitive memory and the generation of newborn young neurons. We used a modified multiple platform method for the selective REM-SD without altering non-REM (NREM) sleep. We found that 24 h of REM-SD, soon after trace-conditioning, impaired the trace-appetitive memory and the training-induced cell proliferation. Nevertheless, 96 h of REM-SD (3 days after the training) did not impair trace memory. Interestingly, 96 h of REM-SD altered the generation of newborn young neurons. These results suggest that REM sleep plays an essential role in training-induced cell proliferation and the fate determination of the newly generated cells toward the neuronal lineage.
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Affiliation(s)
- Shweta Tripathi
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sushil K. Jha
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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16
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Surget A, Belzung C. Adult hippocampal neurogenesis shapes adaptation and improves stress response: a mechanistic and integrative perspective. Mol Psychiatry 2022; 27:403-421. [PMID: 33990771 PMCID: PMC8960391 DOI: 10.1038/s41380-021-01136-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 04/09/2021] [Accepted: 04/19/2021] [Indexed: 02/03/2023]
Abstract
Adult hippocampal neurogenesis (AHN) represents a remarkable form of neuroplasticity that has increasingly been linked to the stress response in recent years. However, the hippocampus does not itself support the expression of the different dimensions of the stress response. Moreover, the main hippocampal functions are essentially preserved under AHN depletion and adult-born immature neurons (abGNs) have no extrahippocampal projections, which questions the mechanisms by which abGNs influence functions supported by brain areas far from the hippocampus. Within this framework, we propose that through its computational influences AHN is pivotal in shaping adaption to environmental demands, underlying its role in stress response. The hippocampus with its high input convergence and output divergence represents a computational hub, ideally positioned in the brain (1) to detect cues and contexts linked to past, current and predicted stressful experiences, and (2) to supervise the expression of the stress response at the cognitive, affective, behavioral, and physiological levels. AHN appears to bias hippocampal computations toward enhanced conjunctive encoding and pattern separation, promoting contextual discrimination and cognitive flexibility, reducing proactive interference and generalization of stressful experiences to safe contexts. These effects result in gating downstream brain areas with more accurate and contextualized information, enabling the different dimensions of the stress response to be more appropriately set with specific contexts. Here, we first provide an integrative perspective of the functional involvement of AHN in the hippocampus and a phenomenological overview of the stress response. We then examine the mechanistic underpinning of the role of AHN in the stress response and describe its potential implications in the different dimensions accompanying this response.
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Affiliation(s)
- A Surget
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.
| | - C Belzung
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.
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17
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Hippocampal neurogenesis promotes preference for future rewards. Mol Psychiatry 2021; 26:6317-6335. [PMID: 34021262 DOI: 10.1038/s41380-021-01165-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/29/2021] [Accepted: 05/06/2021] [Indexed: 02/04/2023]
Abstract
Adult hippocampal neurogenesis has been implicated in a number of disorders where reward processing is disrupted but whether new neurons regulate specific aspects of reward-related decision making remains unclear. Given the role of the hippocampus in future-oriented cognition, here we tested whether adult neurogenesis regulates preference for future, advantageous rewards in a delay discounting paradigm for rats. Indeed, blocking neurogenesis caused a profound aversion for delayed rewards, and biased choice behavior toward immediately available, but smaller, rewards. Consistent with a role for the ventral hippocampus in impulsive decision making and future-thinking, neurogenesis-deficient animals displayed reduced activity in the ventral hippocampus. In intact animals, delay-based decision making restructured dendrites and spines in adult-born neurons and specifically activated adult-born neurons in the ventral dentate gyrus, relative to dorsal activation in rats that chose between immediately-available rewards. Putative developmentally-born cells, located in the superficial granule cell layer, did not display task-specific activity. These findings identify a novel and specific role for neurogenesis in decisions about future rewards, thereby implicating newborn neurons in disorders where short-sighted gains are preferred at the expense of long-term health.
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18
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Within-Trial Persistence of Learned Behavior as a Dissociable Behavioral Component in Hippocampus-Dependent Memory Tasks: A Potential Postlearning Role of Immature Neurons in the Adult Dentate Gyrus. eNeuro 2021; 8:ENEURO.0195-21.2021. [PMID: 34281981 PMCID: PMC8387154 DOI: 10.1523/eneuro.0195-21.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/17/2021] [Accepted: 06/21/2021] [Indexed: 12/20/2022] Open
Abstract
The term “memory strength” generally refers to how well one remembers something. But more precisely it contains multiple modalities, such as how easily, how accurately, how confidently and how vividly we remember it. In human, these modalities of memory strength are dissociable. In this study, we asked whether we can isolate a behavioral component that is dissociable from others in hippocampus-dependent memory tasks in mice, which potentially reflect a modality of memory strength. Using a virus-mediated inducible method, we ablated immature neurons in the dentate gyrus in mice after we trained the mice with hippocampus-dependent memory tasks normally. In memory retrieval tests, these ablated mice initially showed intact performance. However, the ablated mice ceased learned behavior prematurely within a trial compared with control mice. In addition, the ablated mice showed shorter duration of individual episodes of learned behavior. Both affected behavioral measurements point to persistence of learned behavior. Thus, the effect of the postlearning manipulation showed dissociation between initial performance and persistence of learned behavior. These two behavioral components are likely to reflect different brain functions and be mediated by separate mechanisms, which might represent different modalities of memory strength. These simple dissociable measurements in widely used behavioral paradigms would be useful to understand detailed mechanisms underlying the expression of learned behavior and potentially different modalities of memory strength in mice. We also discuss a potential role that immature neurons in the dentate gyrus may play in persistence of learned behavior.
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19
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Haan N, Westacott LJ, Carter J, Owen MJ, Gray WP, Hall J, Wilkinson LS. Haploinsufficiency of the schizophrenia and autism risk gene Cyfip1 causes abnormal postnatal hippocampal neurogenesis through microglial and Arp2/3 mediated actin dependent mechanisms. Transl Psychiatry 2021; 11:313. [PMID: 34031371 PMCID: PMC8144403 DOI: 10.1038/s41398-021-01415-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 04/21/2021] [Accepted: 05/04/2021] [Indexed: 12/12/2022] Open
Abstract
Genetic risk factors can significantly increase chances of developing psychiatric disorders, but the underlying biological processes through which this risk is effected remain largely unknown. Here we show that haploinsufficiency of Cyfip1, a candidate risk gene present in the pathogenic 15q11.2(BP1-BP2) deletion may impact on psychopathology via abnormalities in cell survival and migration of newborn neurons during postnatal hippocampal neurogenesis. We demonstrate that haploinsufficiency of Cyfip1 leads to increased numbers of adult-born hippocampal neurons due to reduced apoptosis, without altering proliferation. We show this is due to a cell autonomous failure of microglia to induce apoptosis through the secretion of the appropriate factors, a previously undescribed mechanism. Furthermore, we show an abnormal migration of adult-born neurons due to altered Arp2/3 mediated actin dynamics. Together, our findings throw new light on how the genetic risk candidate Cyfip1 may influence the hippocampus, a brain region with strong evidence for involvement in psychopathology.
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Affiliation(s)
- Niels Haan
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK.
| | - Laura J Westacott
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
| | - Jenny Carter
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
| | - Michael J Owen
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
| | - William P Gray
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
- Brain Repair and Intercranial Neurotherapeutics Unit, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
- Hodge Centre for Neuropsychiatric Immunology, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
| | - Jeremy Hall
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
- Hodge Centre for Neuropsychiatric Immunology, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
| | - Lawrence S Wilkinson
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
- Hodge Centre for Neuropsychiatric Immunology, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK
- School of Psychology, Cardiff University, Tower Building, Cardiff, UK
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20
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Diaz-Jimenez D, Kolb JP, Cidlowski JA. Glucocorticoids as Regulators of Macrophage-Mediated Tissue Homeostasis. Front Immunol 2021; 12:669891. [PMID: 34079551 PMCID: PMC8165320 DOI: 10.3389/fimmu.2021.669891] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/05/2021] [Indexed: 02/06/2023] Open
Abstract
Our immune system has evolved as a complex network of cells and tissues tasked with maintaining host homeostasis. This is evident during the inflammatory responses elicited during a microbial infection or traumatic tissue damage. These responses seek to eliminate foreign material or restore tissue integrity. Even during periods without explicit disturbances, the immune system plays prominent roles in tissue homeostasis. Perhaps one of the most studied cells in this regard is the macrophage. Tissue-resident macrophages are a heterogenous group of sensory cells that respond to a variety of environmental cues and are essential for organ function. Endogenously produced glucocorticoid hormones connect external environmental stress signals with the function of many cell types, producing profound changes in immune cells, including macrophages. Here, we review the current literature which demonstrates specific effects of glucocorticoids in several organ systems. We propose that tissue-resident macrophages, through glucocorticoid signaling, may play an underappreciated role as regulators of organ homeostasis.
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Affiliation(s)
- David Diaz-Jimenez
- Molecular Endocrinology Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States
| | - Joseph P Kolb
- Molecular Endocrinology Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States
| | - John A Cidlowski
- Molecular Endocrinology Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States
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21
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Nonaka M, Taylor WW, Bukalo O, Tucker LB, Fu AH, Kim Y, McCabe JT, Holmes A. Behavioral and Myelin-Related Abnormalities after Blast-Induced Mild Traumatic Brain Injury in Mice. J Neurotrauma 2021; 38:1551-1571. [PMID: 33605175 DOI: 10.1089/neu.2020.7254] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In civilian and military settings, mild traumatic brain injury (mTBI) is a common consequence of impacts to the head, sudden blows to the body, and exposure to high-energy atmospheric shockwaves from blast. In some cases, mTBI from blast exposure results in long-term emotional and cognitive deficits and an elevated risk for certain neuropsychiatric diseases. Here, we tested the effects of mTBI on various forms of auditory-cued fear learning and other measures of cognition in male C57BL/6J mice after single or repeated blast exposure (blast TBI; bTBI). bTBI produced an abnormality in the temporal organization of cue-induced freezing behavior in a conditioned trace fear test. Spatial working memory, evaluated by the Y-maze task performance, was also deleteriously affected by bTBI. Reverse-transcription quantitative real-time polymerase chain reaction (RT-qPCR) analysis for glial markers indicated an alteration in the expression of myelin-related genes in the hippocampus and corpus callosum 1-8 weeks after bTBI. Immunohistochemical and ultrastructural analyses detected bTBI-related myelin and axonal damage in the hippocampus and corpus callosum. Together, these data suggest a possible link between blast-induced mTBI, myelin/axonal injury, and cognitive dysfunction.
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Affiliation(s)
- Mio Nonaka
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health (NIH), Rockville, Maryland, USA
| | - William W Taylor
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health (NIH), Rockville, Maryland, USA
| | - Olena Bukalo
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health (NIH), Rockville, Maryland, USA
| | - Laura B Tucker
- Department of Anatomy, Physiology and Genetics, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,Preclinical Studies Core, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Amanda H Fu
- Department of Anatomy, Physiology and Genetics, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,Preclinical Studies Core, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Yeonho Kim
- Department of Anatomy, Physiology and Genetics, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,Preclinical Studies Core, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Joseph T McCabe
- Department of Anatomy, Physiology and Genetics, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,Preclinical Studies Core, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health (NIH), Rockville, Maryland, USA
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22
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Matsuda VDV, Tejada MB, Motta-Teixeira LC, Ikebara JM, Cardoso DS, Machado-Nils AV, Lee VY, Diccini I, Arruda BP, Martins PP, Dias NMM, Tessarotto RP, Raeisossadati R, Bruno M, Takase LF, Kihara AH, Nogueira MI, Xavier GF, Takada SH. Impact of neonatal anoxia and hypothermic treatment on development and memory of rats. Exp Neurol 2021; 340:113691. [PMID: 33713657 DOI: 10.1016/j.expneurol.2021.113691] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 02/18/2021] [Accepted: 03/07/2021] [Indexed: 01/02/2023]
Abstract
Therapeutic hypothermia (TH) is well established as a standard treatment for term and near-term infants. However, therapeutic effects of hypothermia following neonatal anoxia in very premature babies remains inconclusive. The present rodent model of preterm neonatal anoxia has been shown to alter developmental milestones and hippocampal neurogenesis, and to disrupt spatial learning and memory in adulthood. These effects seem to be reduced by post-insult hypothermia. Epigenetic-related mechanisms have been postulated as valuable tools for developing new therapies. Dentate gyrus neurogenesis is regulated by epigenetic factors. This study evaluated whether TH effects in a rodent model of preterm oxygen deprivation are based on epigenetic alterations. The effects of TH on both developmental features (somatic growth, maturation of physical characteristics and early neurological reflexes) and performance of behavioral tasks at adulthood (spatial reference and working memory, and fear conditioning) were investigated in association with the possible involvement of the epigenetic operator Enhancer of zeste homolog 2 (Ezh2), possibly related to long-lasting effects on hippocampal neurogenesis. Results showed that TH reduced both anoxia-induced hippocampal neurodegeneration and anoxia-induced impairments on risk assessment behavior, acquisition of spatial memory, and extinction of auditory and contextual fear conditioning. In contrast, TH did not prevent developmental alterations caused by neonatal anoxia and did not restore hippocampal neurogenesis or cause changes in EZH2 levels. In conclusion, despite the beneficial effects of TH in hippocampal neurodegeneration and in reversing disruption of performance of behavioral tasks following oxygen deprivation in prematurity, these effects seem not related to developmental alterations and hippocampal neurogenesis and, apparently, is not caused by Ezh2-mediated epigenetic alteration.
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Affiliation(s)
- Victor Daniel Vasquez Matsuda
- Neuroscience and Behaviour Laboratory, Department of Physiology, Institute of Biosciences, Universidade de São Paulo, São Paulo, SP, Brazil; Neuroscience Laboratory, Department of Anatomy, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Martin Bustelo Tejada
- Department of Pediatrics, Maastricht University Medical Center (MUMC), Maastricht, the Netherlands; Experimental Neuropathology Laboratory, Institute of Cellular Biology and Neuroscience "Prof. E. De Robertis" (IBCN), Faculty of Medicine, University of Buenos Aires, CONICET, Buenos Aires, Argentina; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Maastricht University, Maastricht, the Netherlands; Biomedical Sciences Institute, Faculty of Medical Sciences, Catholic University of Cuyo, San Juan, Argentina; Neurogenetics Laboratory, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil
| | - Lívia Clemente Motta-Teixeira
- Neuroscience and Behaviour Laboratory, Department of Physiology, Institute of Biosciences, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Juliane Midori Ikebara
- Neurogenetics Laboratory, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil
| | | | - Aline Vilar Machado-Nils
- Neuroscience and Behaviour Laboratory, Department of Physiology, Institute of Biosciences, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Vitor Yonamine Lee
- Neuroscience Laboratory, Department of Anatomy, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Isabelle Diccini
- Neuroscience Laboratory, Department of Anatomy, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Bruna Petrucelli Arruda
- Neuroscience Laboratory, Department of Anatomy, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo, SP, Brazil; Neurogenetics Laboratory, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil
| | | | | | | | - Reza Raeisossadati
- Neurogenetics Laboratory, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil
| | - Martin Bruno
- Biomedical Sciences Institute, Faculty of Medical Sciences, Catholic University of Cuyo, San Juan, Argentina; National Council of Scientific and Technical Research (CONICET), Argentina
| | - Luiz Fernando Takase
- Department of Morphology and Pathology, Biological Sciences and Health Center, Universidade Federal de São Carlos, São Carlos, Brazil
| | | | - Maria Inês Nogueira
- Neuroscience Laboratory, Department of Anatomy, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Gilberto Fernando Xavier
- Neuroscience and Behaviour Laboratory, Department of Physiology, Institute of Biosciences, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Silvia Honda Takada
- Neurogenetics Laboratory, Universidade Federal do ABC, São Bernardo do Campo, SP, Brazil.
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Lensu S, Waselius T, Mäkinen E, Kettunen H, Virtanen A, Tiirola M, Penttonen M, Pekkala S, Nokia MS. Irradiation of the head reduces adult hippocampal neurogenesis and impairs spatial memory, but leaves overall health intact in rats. Eur J Neurosci 2021; 53:1885-1904. [PMID: 33382141 DOI: 10.1111/ejn.15102] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/21/2020] [Accepted: 12/28/2020] [Indexed: 12/19/2022]
Abstract
Treatment of brain cancer, glioma, can cause cognitive impairment as a side-effect, possibly because it disrupts the integrity of the hippocampus, a structure vital for normal memory. Radiotherapy is commonly used to treat glioma, but the effects of irradiation on the brain are still poorly understood, and other biological effects have not been extensively studied. Here, we exposed healthy adult male rats to moderate-dose irradiation of the head. We found no effect of irradiation on systemic inflammation, weight gain or gut microbiota diversity, although it increased the abundance of Bacteroidaceae family, namely Bacteroides genus in the gut microbiota. Irradiation had no effect on long-term potentiation in the CA3-CA1 synapse or endogenous hippocampal electrophysiology, but it did reduce adult hippocampal neurogenesis and impaired short-term spatial recognition memory. However, no overall cognitive impairment was observed. To summarize, our results suggest that in adult male rats head irradiation does not compromise health or cognition overall even though the number of new, adult-born hippocampal neurons is decreased. Thus, the sole effects of head irradiation on the body, brain and cognition might be less harmful than previously thought, and the cognitive decline experienced by cancer patients might originate from physiological and mental effects of the disease itself. Therefore, to increase the translational value of animal studies, the effects of irradiation should be studied together with cancer, in older animals, using varying irradiation protocols and doses.
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Affiliation(s)
- Sanna Lensu
- Faculty of Sport and Health Sciences, University of Jyvaskyla, Jyvaskyla, Finland.,Department of Psychology, University of Jyvaskyla, Jyvaskyla, Finland
| | - Tomi Waselius
- Department of Psychology, University of Jyvaskyla, Jyvaskyla, Finland
| | - Elina Mäkinen
- Faculty of Sport and Health Sciences, University of Jyvaskyla, Jyvaskyla, Finland
| | - Heikki Kettunen
- Department of Physics, University of Jyvaskyla, Jyvaskyla, Finland
| | - Ari Virtanen
- Department of Physics, University of Jyvaskyla, Jyvaskyla, Finland
| | - Marja Tiirola
- Department of Biological and Environmental Sciences, University of Jyvaskyla, Jyvaskyla, Finland
| | - Markku Penttonen
- Department of Psychology, University of Jyvaskyla, Jyvaskyla, Finland
| | - Satu Pekkala
- Faculty of Sport and Health Sciences, University of Jyvaskyla, Jyvaskyla, Finland
| | - Miriam S Nokia
- Department of Psychology, University of Jyvaskyla, Jyvaskyla, Finland
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24
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Reddaway J, Brydges NM. Enduring neuroimmunological consequences of developmental experiences: From vulnerability to resilience. Mol Cell Neurosci 2020; 109:103567. [PMID: 33068720 PMCID: PMC7556274 DOI: 10.1016/j.mcn.2020.103567] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 09/14/2020] [Accepted: 10/12/2020] [Indexed: 12/14/2022] Open
Abstract
The immune system is crucial for normal neuronal development and function (neuroimmune system). Both immune and neuronal systems undergo significant postnatal development and are sensitive to developmental programming by environmental experiences. Negative experiences from infection to psychological stress at a range of different time points (in utero to adolescence) can permanently alter the function of the neuroimmune system: given its prominent role in normal brain development and function this dysregulation may increase vulnerability to psychiatric illness. In contrast, positive experiences such as exercise and environmental enrichment are protective and can promote resilience, even restoring the detrimental effects of negative experiences on the neuroimmune system. This suggests the neuroimmune system is a viable therapeutic target for treatment and prevention of psychiatric illnesses, especially those related to stress. In this review we will summarise the main cells, molecules and functions of the immune system in general and with specific reference to central nervous system development and function. We will then discuss the effects of negative and positive environmental experiences, especially during development, in programming the long-term functioning of the neuroimmune system. Finally, we will review the sparse but growing literature on sex differences in neuroimmune development and response to environmental experiences. The immune system is essential for development and function of the central nervous system (neuroimmune system) Environmental experiences can permanently alter neuroimmune function and associated brain development Altered neuroimmune function following negative developmental experiences may play a role in psychiatric illnesses Positive experiences can promote resilience and rescue the effects of negative experiences on the neuroimmune system The neuroimmune system is therefore a viable therapeutic target for preventing and treating psychiatric illnesses
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Affiliation(s)
- Jack Reddaway
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK
| | - Nichola M Brydges
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK.
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25
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Doublecortin-Like Is Implicated in Adult Hippocampal Neurogenesis and in Motivational Aspects to Escape from an Aversive Environment in Male Mice. eNeuro 2020; 7:ENEURO.0324-19.2020. [PMID: 32994174 PMCID: PMC7568604 DOI: 10.1523/eneuro.0324-19.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 08/12/2020] [Accepted: 08/14/2020] [Indexed: 12/02/2022] Open
Abstract
Doublecortin (DCX)-like (DCL) is a microtubule (MT)-associated protein (MAP) that is highly homologous to DCX and is crucially involved in embryonic neurogenesis. Here, we have investigated the in vivo role of DCL in adult hippocampal neurogenesis by generating transgenic mice producing inducible shRNA molecules that specifically target DCL but no other splice variants produced by the DCLK gene. DCL knock-down (DCL-KD) resulted in a significant increase in the number of proliferating BrdU+ cells in the subgranular zone (SGZ) 1 d after BrdU administration. However, the number of surviving newborn adult NeuN+/BrdU+ neurons are significantly decreased when inspected four weeks after BrdU administration suggesting a blockade of neuronal differentiation after DCL-KD. In line with this, we observed an increase in the number of proliferating cells, but a significant decrease in postmitotic DCX+ cells that are characterized by long dendrites spanning all dentate gyrus layers. Behavioral analysis showed that DCL-KD strongly extended the escape latency of mice on the circular hole board (CHB) but did not affect other aspects of this behavioral task. Together, our results indicate a function for DCL in adult neurogenesis and in the motivation to escape from an aversive environment. In contrast to DCX, its pivotal role in the maturation of postmitotic neuronal progenitor cells (NPCs) marks DCL as a genuine adult neurogenesis indicator in the hippocampus.
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26
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Sateesh S, Abraham WC. Neurophysiological and molecular approaches to understanding the mechanisms of learning and memory. J R Soc N Z 2020. [DOI: 10.1080/03036758.2020.1796719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Shruthi Sateesh
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Wickliffe C. Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
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27
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Traumatic brain injury and hippocampal neurogenesis: Functional implications. Exp Neurol 2020; 331:113372. [PMID: 32504636 DOI: 10.1016/j.expneurol.2020.113372] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 05/23/2020] [Accepted: 05/30/2020] [Indexed: 12/15/2022]
Abstract
In the adult brain, self-renewing radial-glia like (RGL) progenitor cells have been shown to reside in the subventricular zone and the subgranular zone of the hippocampus. A large body of evidence shows that experiences such as learning, enriched environment and stress can alter proliferation and differentiation of RGL progenitor cells. The progenitor cells present in the subgranular zone of the hippocampus divide to give rise to newborn neurons that migrate to the dentate gyrus where they differentiate into adult granule neurons. These newborn neurons have been found to have a unique role in certain types of hippocampus-dependent learning and memory, including goal-directed behaviors that require pattern separation. Experimental traumatic brain injury (TBI) in rodents has been shown to alter hippocampal neurogenesis, including triggering the acute loss of newborn neurons, as well as progenitor cell hyper-proliferation. In this review, we discuss the role of hippocampal neurogenesis in learning and memory. Furthermore, we review evidence for the molecular mechanisms that contribute to newborn neuron loss, as well as increased progenitor cell proliferation after TBI. Finally, we discuss strategies aimed at enhancing neurogenesis after TBI and their possible therapeutic benefits.
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28
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Prevention of age-associated neuronal hyperexcitability with improved learning and attention upon knockout or antagonism of LPAR2. Cell Mol Life Sci 2020; 78:1029-1050. [PMID: 32468095 PMCID: PMC7897625 DOI: 10.1007/s00018-020-03553-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 04/16/2020] [Accepted: 05/13/2020] [Indexed: 12/20/2022]
Abstract
Recent studies suggest that synaptic lysophosphatidic acids (LPAs) augment glutamate-dependent cortical excitability and sensory information processing in mice and humans via presynaptic LPAR2 activation. Here, we studied the consequences of LPAR2 deletion or antagonism on various aspects of cognition using a set of behavioral and electrophysiological analyses. Hippocampal neuronal network activity was decreased in middle-aged LPAR2−/− mice, whereas hippocampal long-term potentiation (LTP) was increased suggesting cognitive advantages of LPAR2−/− mice. In line with the lower excitability, RNAseq studies revealed reduced transcription of neuronal activity markers in the dentate gyrus of the hippocampus in naïve LPAR2−/− mice, including ARC, FOS, FOSB, NR4A, NPAS4 and EGR2. LPAR2−/− mice behaved similarly to wild-type controls in maze tests of spatial or social learning and memory but showed faster and accurate responses in a 5-choice serial reaction touchscreen task requiring high attention and fast spatial discrimination. In IntelliCage learning experiments, LPAR2−/− were less active during daytime but normally active at night, and showed higher accuracy and attention to LED cues during active times. Overall, they maintained equal or superior licking success with fewer trials. Pharmacological block of the LPAR2 receptor recapitulated the LPAR2−/− phenotype, which was characterized by economic corner usage, stronger daytime resting behavior and higher proportions of correct trials. We conclude that LPAR2 stabilizes neuronal network excitability upon aging and allows for more efficient use of resting periods, better memory consolidation and better performance in tasks requiring high selective attention. Therapeutic LPAR2 antagonism may alleviate aging-associated cognitive dysfunctions.
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29
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Petkova SP, Pride M, Klocke C, Fenton TA, White J, Lein PJ, Ellegood J, Lerch JP, Silverman JL, Waldau B. Cyclin D2-knock-out mice with attenuated dentate gyrus neurogenesis have robust deficits in long-term memory formation. Sci Rep 2020; 10:8204. [PMID: 32424171 PMCID: PMC7235216 DOI: 10.1038/s41598-020-65090-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/23/2020] [Indexed: 02/07/2023] Open
Abstract
Neurobehavioral studies have produced contradictory findings concerning the function of neurogenesis in the adult dentate gyrus. Previous studies have proved inconsistent across several behavioral endpoints thought to be dependent on dentate neurogenesis, including memory acquisition, short-term and long-term retention of memory, pattern separation, and reversal learning. We hypothesized that the main function of dentate neurogenesis is long-term memory formation because we assumed that a newly formed and integrated neuron would have a long-term impact on the local neural network. We used a cyclin D2-knock-out (cyclin D2−/−) mouse model of endogenously deficient dentate neurogenesis to test this hypothesis. We found that cyclin D2−/− mice had robust and sustained loss of long-term memory in two separate behavioral tasks, Morris water maze (MWM) and touchscreen intermediate pattern separation. Moreover, after adjusting for differences in brain volumes determined by magnetic resonance (MR) imaging, reduced dentate neurogenesis moderately correlated with deficits in memory retention after 24 hours. Importantly, cyclin D2−/− mice did not show deficits in learning acquisition in a touchscreen paradigm of intermediate pattern separation or MWM platform location, indicating intact short-term memory. Further evaluation of cyclin D2−/− mice is necessary to confirm that deficits are specifically linked to dentate gyrus neurogenesis since cyclin D2−/− mice also have a reduced size of the olfactory bulb, hippocampus, cerebellum and cortex besides reduced dentate gyrus neurogenesis.
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Affiliation(s)
- Stela P Petkova
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA, 95817, US
| | - Michael Pride
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA, 95817, US
| | - Carolyn Klocke
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA, 95616, US
| | - Timothy A Fenton
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA, 95817, US
| | - Jeannine White
- Institute for Regenerative Cures, Sacramento, CA, 95817, US
| | - Pamela J Lein
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA, 95616, US.,MIND Institute, UC Davis, Sacramento, CA, 95817, US
| | - Jacob Ellegood
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, M5T 3H7, Canada
| | - Jason P Lerch
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, M5T 3H7, Canada.,Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neuroscience,The University of Oxford, Oxford, OX3 9DU, UK
| | - Jill L Silverman
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA, 95817, US.,MIND Institute, UC Davis, Sacramento, CA, 95817, US
| | - Ben Waldau
- Department of Neurological Surgery, UC Davis Medical Center, Sacramento, CA, 95817, US.
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30
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Tripathi S, Verma A, Jha SK. Training on an Appetitive Trace-Conditioning Task Increases Adult Hippocampal Neurogenesis and the Expression of Arc, Erk and CREB Proteins in the Dorsal Hippocampus. Front Cell Neurosci 2020; 14:89. [PMID: 32362814 PMCID: PMC7181388 DOI: 10.3389/fncel.2020.00089] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 03/26/2020] [Indexed: 12/11/2022] Open
Abstract
Adult hippocampal neurogenesis (AHN) plays an essential role in hippocampal-dependent memory consolidation. Increased neurogenesis enhances learning, whereas its ablation causes memory impairment. In contrast, few reports suggest that neurogenesis reduces after learning. Although the interest in exploring the role of adult neurogenesis in learning has been growing, the evidence is still limited. The role of the trace- and delay-appetitive-conditioning on AHN and its underlying mechanism are not known. The consolidation of trace-conditioned memory requires the hippocampus, but delay-conditioning does not. Moreover, the dorsal hippocampus (DH) and ventral hippocampus (VH) may have a differential role in these two conditioning paradigms. Here, we have investigated the changes in: (A) hippocampal cell proliferation and their progression towards neuronal lineage; and (B) expression of Arc, Erk1, Erk2, and CREB proteins in the DH and VH after trace- and delay-conditioning in the rat. The number of newly generated cells significantly increased in the trace-conditioned but did not change in the delay-conditioned animals compared to the control group. Similarly, the expression of Arc protein significantly increased in the DH but not in the VH after trace-conditioning. Nonetheless, it remains unaltered in the delay-conditioned group. The expression of pErk1, pErk2, and pCREB also increased in the DH after trace-conditioning. Whereas, the expression of only pErk1 pErk2 and pCREB proteins increased in the VH after delay-conditioning. Our results suggest that appetitive trace-conditioning enhances AHN. The increased DH neuronal activation and pErk1, pErk2, and pCREB in the DH may be playing an essential role in learning-induced cell-proliferation after appetitive trace-conditioning.
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Affiliation(s)
- Shweta Tripathi
- School of Life Science, Jawaharlal Nehru University, New Delhi, India
| | - Anita Verma
- School of Life Science, Jawaharlal Nehru University, New Delhi, India
| | - Sushil K Jha
- School of Life Science, Jawaharlal Nehru University, New Delhi, India
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31
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Bobkova NV, Poltavtseva RA, Leonov SV, Sukhikh GT. Neuroregeneration: Regulation in Neurodegenerative Diseases and Aging. BIOCHEMISTRY (MOSCOW) 2020; 85:S108-S130. [PMID: 32087056 DOI: 10.1134/s0006297920140060] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
It had been commonly believed for a long time, that once established, degeneration of the central nervous system (CNS) is irreparable, and that adult person merely cannot restore dead or injured neurons. The existence of stem cells (SCs) in the mature brain, an organ with minimal regenerative ability, had been ignored for many years. Currently accepted that specific structures of the adult brain contain neural SCs (NSCs) that can self-renew and generate terminally differentiated brain cells, including neurons and glia. However, their contribution to the regulation of brain activity and brain regeneration in natural aging and pathology is still a subject of ongoing studies. Since the 1970s, when Fuad Lechin suggested the existence of repair mechanisms in the brain, new exhilarating data from scientists around the world have expanded our knowledge on the mechanisms implicated in the generation of various cell phenotypes supporting the brain, regulation of brain activity by these newly generated cells, and participation of SCs in brain homeostasis and regeneration. The prospects of the SC research are truthfully infinite and hitherto challenging to forecast. Once researchers resolve the issues regarding SC expansion and maintenance, the implementation of the SC-based platform could help to treat tissues and organs impaired or damaged in many devastating human diseases. Over the past 10 years, the number of studies on SCs has increased exponentially, and we have already become witnesses of crucial discoveries in SC biology. Comprehension of the mechanisms of neurogenesis regulation is essential for the development of new therapeutic approaches for currently incurable neurodegenerative diseases and neuroblastomas. In this review, we present the latest achievements in this fast-moving field and discuss essential aspects of NSC biology, including SC regulation by hormones, neurotransmitters, and transcription factors, along with the achievements of genetic and chemical reprogramming for the safe use of SCs in vitro and in vivo.
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Affiliation(s)
- N V Bobkova
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
| | - R A Poltavtseva
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia. .,National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V. I. Kulakov, Ministry of Healthcare of Russian Federation, Moscow, 117997, Russia
| | - S V Leonov
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia. .,Moscow Institute of Physics and Technology (National Research University), The Phystech School of Biological and Medical Physics, Dolgoprudny, Moscow Region, 141700, Russia
| | - G T Sukhikh
- National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V. I. Kulakov, Ministry of Healthcare of Russian Federation, Moscow, 117997, Russia.
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32
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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: 30] [Impact Index Per Article: 7.5] [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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Lucassen PJ, Fitzsimons CP, Salta E, Maletic-Savatic M. Adult neurogenesis, human after all (again): Classic, optimized, and future approaches. Behav Brain Res 2020; 381:112458. [DOI: 10.1016/j.bbr.2019.112458] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 11/29/2019] [Accepted: 12/28/2019] [Indexed: 02/08/2023]
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Dugré JR, Bitar N, Dumais A, Potvin S. Limbic Hyperactivity in Response to Emotionally Neutral Stimuli in Schizophrenia: A Neuroimaging Meta-Analysis of the Hypervigilant Mind. Am J Psychiatry 2019; 176:1021-1029. [PMID: 31509006 DOI: 10.1176/appi.ajp.2019.19030247] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE It has long been assumed that paranoid ideation may stem from an aberrant limbic response to threatening stimuli. However, results from functional neuroimaging studies using negative emotional stimuli have failed to confirm this assumption. One of the potential reasons for the lack of effect is that study participants with psychosis may display aberrant brain responses to neutral material rather than to threatening stimuli. The authors conducted a functional neuroimaging meta-analysis to test this hypothesis. METHODS A literature search was performed with PubMed, Google Scholar, and Embase to identify functional neuroimaging studies examining brain responses to neutral material in patients with psychosis. A total of 23 studies involving schizophrenia patients were retrieved. Using t-maps of peak coordinates to calculate effect sizes, a random-effects model meta-analysis was performed with the anisotropic effect-size version of Seed-based d Mapping software. RESULTS In schizophrenia patients relative to healthy control subjects, increased activations were observed in the left and right amygdala and parahippocampus and the left putamen, hippocampus, and insula in response to neutral stimuli. CONCLUSIONS Given that several limbic regions were found to be more activated in schizophrenia patients than in control subjects, the results of this meta-analysis strongly suggest that these patients confer aberrant emotional significance to nonthreatening stimuli. In theory, this abnormal brain reactivity may fuel delusional thoughts. Studies are needed in individuals at risk of psychosis to determine whether aberrant limbic reactivity to neutral stimuli is an early neurofunctional marker of psychosis vulnerability.
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Affiliation(s)
- Jules R Dugré
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Montreal (all authors); Department of Psychiatry and Addictology, Faculty of Medicine, University of Montreal, Montreal (all authors); and Institut Philippe-Pinel de Montréal, Montreal (Dumais)
| | - Nathalie Bitar
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Montreal (all authors); Department of Psychiatry and Addictology, Faculty of Medicine, University of Montreal, Montreal (all authors); and Institut Philippe-Pinel de Montréal, Montreal (Dumais)
| | - Alexandre Dumais
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Montreal (all authors); Department of Psychiatry and Addictology, Faculty of Medicine, University of Montreal, Montreal (all authors); and Institut Philippe-Pinel de Montréal, Montreal (Dumais)
| | - Stéphane Potvin
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Montreal (all authors); Department of Psychiatry and Addictology, Faculty of Medicine, University of Montreal, Montreal (all authors); and Institut Philippe-Pinel de Montréal, Montreal (Dumais)
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35
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Hassien AM, Shue F, Bernier BE, Drew MR. A mouse model of stress-enhanced fear learning demonstrates extinction-sensitive and extinction-resistant effects of footshock stress. Behav Brain Res 2019; 379:112391. [PMID: 31785363 DOI: 10.1016/j.bbr.2019.112391] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/31/2019] [Accepted: 11/25/2019] [Indexed: 12/24/2022]
Abstract
Stressful experiences can cause long-lasting sensitization of fear and anxiety that extends beyond the circumstances of the initial trauma. The neural mechanisms of these stress effects have been studied extensively in rats using the stress-enhanced fear learning (SEFL) paradigm, in which exposure to footshock stress potentiates subsequent fear conditioning. Here we establish a mouse version of the SEFL paradigm. Male and female 129s6 mice received four 1-mA footshocks or equivalent context exposure without shock. Shock exposure induced Pavlovian fear conditioning to the shock context and produced three more general effects: (1) suppression of open field exploration, (2) potentiated unconditioned fear of a novel tone stimulus, and (3) enhanced fear conditioning in a novel context. To determine whether these effects of footshock stress reflect generalized Pavlovian fear conditioning versus nonassociative fear sensitization, some mice received extinction training in the footshock stress context, which reduced contextual fear to the levels of unstressed control mice. Extinction restored normal open field exploration, suggesting that this effect of stress reflects generalized Pavlovian fear. In contrast, extinction failed to attenuate stress-enhanced fear, indicating that stress-enhanced fear is nonassociative and mechanistically distinct from Pavlovian fear conditioning. The effects of footshock stress were similar in male and female mice, although female mice displayed larger acute responses to fear-inducing stimuli than did males. The results demonstrate that footshock stress influences emotional behavior through distinct associative and nonassociative mechanisms, which likely involve unique neural underpinnings.
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Affiliation(s)
- Alexa M Hassien
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Francis Shue
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Brian E Bernier
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Michael R Drew
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA.
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36
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The Microtubule Severing Protein Katanin Regulates Proliferation of Neuronal Progenitors in Embryonic and Adult Neurogenesis. Sci Rep 2019; 9:15940. [PMID: 31685876 PMCID: PMC6828949 DOI: 10.1038/s41598-019-52367-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 10/12/2019] [Indexed: 12/14/2022] Open
Abstract
Microtubule severing regulates cytoskeletal rearrangement underlying various cellular functions. Katanin, a heterodimer, consisting of catalytic (p60) and regulatory (p80) subunits severs dynamic microtubules to modulate several stages of cell division. The role of p60 katanin in the mammalian brain with respect to embryonic and adult neurogenesis is poorly understood. Here, we generated a Katna1 knockout mouse and found that consistent with a critical role of katanin in mitosis, constitutive homozygous Katna1 depletion is lethal. Katanin p60 haploinsufficiency induced an accumulation of neuronal progenitors in the subventricular zone during corticogenesis, and impaired their proliferation in the adult hippocampus dentate gyrus (DG) subgranular zone. This did not compromise DG plasticity or spatial and contextual learning and memory tasks employed in our study, consistent with the interpretation that adult neurogenesis may be associated with selective forms of hippocampal-dependent cognitive processes. Our data identify a critical role for the microtubule-severing protein katanin p60 in regulating neuronal progenitor proliferation in vivo during embryonic development and adult neurogenesis.
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Millon EM, Shors TJ. Taking neurogenesis out of the lab and into the world with MAP Train My Brain™. Behav Brain Res 2019; 376:112154. [PMID: 31421141 DOI: 10.1016/j.bbr.2019.112154] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 07/24/2019] [Accepted: 08/13/2019] [Indexed: 01/22/2023]
Abstract
Neurogenesis in the adult hippocampus was rediscovered in the 1990's after being reported in the 1960's. Since then, thousands upon thousands of laboratories have reported on the characteristics and presumed functional significance of new neurons in the adult brain. In 1999, we reported that mental training with effortful learning could extend the survival of these new cells and in the same year, others reported that physical training with exercise could increase their proliferation. Based on these studies and others, we developed MAP Train My Brain™, which is a brain fitness program for humans. The program combines mental and physical (MAP) training through 30-min of effortful meditation followed by 30-min of aerobic exercise. This program, when practiced twice a week for eight weeks reduced depressive symptoms and ruminative thoughts in men and women with major depressive disorder (MDD) while increasing synchronized brain activity during cognitive control. It also reduced anxiety and depression and increased oxygen consumption in young mothers who had been homeless. Moreover, engaging in the program reduced trauma-related cognitions and ruminative thoughts while increasing self-worth in adult women with a history of sexual trauma. And finally, the combination of mental and physical training together was more effective than either activity alone. Albeit effortful, this program does not require inordinate amounts of time or money to practice and can be easily adopted into everyday life. MAP Training exemplifies how we as neuroscientists can take discoveries made in the laboratory out into the world for the benefit of others.
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Affiliation(s)
- Emma M Millon
- Department of Psychology and Center for Collaborative Neuroscience, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Tracey J Shors
- Department of Psychology and Center for Collaborative Neuroscience, Rutgers University, Piscataway, New Jersey 08854, USA.
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Weeden CSS, Mercurio JC, Cameron HA. A role for hippocampal adult neurogenesis in shifting attention toward novel stimuli. Behav Brain Res 2019; 376:112152. [PMID: 31419520 DOI: 10.1016/j.bbr.2019.112152] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 07/13/2019] [Accepted: 08/12/2019] [Indexed: 12/24/2022]
Abstract
New granule neurons are born in the dentate gyrus region of the hippocampus throughout life. Behavioral effects of slowing or stopping this ongoing neurogenesis are generally observed only in complex cognitive tasks involving high levels of cue or memory interference or in tests of emotion presented after stress exposure. Here, we tested the role of new neurons in naïve rats in a simple, one-trial orienting task previously shown to be affected by hippocampal lesions. Using a pharmacogenetic method to inhibit adult neurogenesis, we found that loss of new neurons decreased orienting toward a novel auditory cue. Rats lacking new neurons showed this change in orienting only when they were drinking from a water bottle and not when they were exploring an empty arena, suggesting that the deficit is not in the ability to orient to a novel sound but in shifting of attention toward a second stimulus. Orienting was reduced to the same extent after 4 or 8 weeks of neurogenesis reduction but was not detectably altered after 2 or 3 weeks of treatment, suggesting that new neurons must mature for approximately a month before functioning in this behavior. These findings demonstrate that adult-born neurons affect behavior in a simple attention reorienting task in naïve animals with no prior stress or task-related learning.
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Affiliation(s)
- Christy S S Weeden
- Section on Neuroplasticity, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Jeffrey C Mercurio
- Section on Neuroplasticity, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Heather A Cameron
- Section on Neuroplasticity, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, United States.
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Sex-specific neurogenic deficits and neurocognitive disorders in middle-aged HIV-1 Tg26 transgenic mice. Brain Behav Immun 2019; 80:488-499. [PMID: 30999016 PMCID: PMC6660421 DOI: 10.1016/j.bbi.2019.04.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 04/11/2019] [Accepted: 04/15/2019] [Indexed: 11/23/2022] Open
Abstract
Varying degrees of cognitive deficits affect over half of all HIV-1 infected patients. Because of antiretroviral treatment (ART) regimens, the HIV-1 patient population is increasing in age. Very few epidemiological studies have focused on sex-specific differences in HIV-1-associated neurocognitive disorders (HAND). The purpose of this study is to examine any possible differences between male and female mice in the progression of cognitive dementia during persistent low-level HIV-1 protein exposure, mimicking the typical clinical setting in the post-ART era. Eight to ten-month old HIV-1 Tg26(+/-) transgenic mice were utilized to assess for specific learning and memory modalities. Initial physiological screening and fear conditioning assessments revealed that Tg26 mice exhibited no significant differences in general behavioral function, contextual fear conditioning, or cued fear conditioning responses when compared to their wild-type (WT) littermates, regardless of sex. However, Barnes maze testing revealed significantly impaired short and long-term spatial memory in males, while females had impaired spatial learning abilities and short-term spatial memory. The potential cellular mechanism underlying these sex-specific neurocognitive deficits was explored with hippocampal neurogenic analysis. Compared to WT mice, both male and female Tg26(+/-) mice had fewer quiescent neural stem cells and neuroblasts in their hippocampi. Male Tg26(+/-) mice had a more robust reduction of the quiescent neural stem cell pool than female Tg26(+/-) mice. While female WT mice had a higher number of neural progenitor cells than male WT mice, only female Tg26(+/-) mice exhibited a robust reduction in the number of neural progenitor cells. Altogether, these results suggest that middle-aged male and female Tg26(+/-) mice manifest differing impairments in cognitive functioning and hippocampal neurogenesis. This study emphasizes the importance of understanding sex related differences in HAND pathology, which would aid in designing more optimized therapeutic regimens for the treatment of HAND.
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Murthy S, Kane GA, Katchur NJ, Lara Mejia PS, Obiofuma G, Buschman TJ, McEwen BS, Gould E. Perineuronal Nets, Inhibitory Interneurons, and Anxiety-Related Ventral Hippocampal Neuronal Oscillations Are Altered by Early Life Adversity. Biol Psychiatry 2019; 85:1011-1020. [PMID: 31027646 PMCID: PMC6590696 DOI: 10.1016/j.biopsych.2019.02.021] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 01/26/2019] [Accepted: 02/19/2019] [Indexed: 02/08/2023]
Abstract
BACKGROUND In humans, accumulated adverse experiences during childhood increase the risk of anxiety disorders and attention-deficit/hyperactivity disorder. In rodents, the ventral hippocampus (vHIP) is associated with anxiety regulation, and lesions in this region alter both anxiety-like behavior and activity levels. Neuronal oscillations in the vHIP of the theta frequency range (4-12 Hz) have been implicated in anxious states and derive in part from the activity of inhibitory interneurons in the hippocampus, some of which are enwrapped with perineuronal nets (PNNs), extracellular matrix structures known to regulate plasticity. We sought to investigate the associations among early life stress-induced anxiety and hyperactivity with vHIP neuronal oscillations, inhibitory interneurons, and PNNs in mice. METHODS We used repeated maternal separation with early weaning (MSEW) to model accumulated early life adversity in mouse offspring and studied the underlying cellular and electrophysiological changes in the vHIP that are associated with excessive anxiety and hyperactivity. RESULTS We found increased anxiety-like behavior and activity levels in MSEW adult males, along with increased theta power and enhanced theta-gamma coupling in the vHIP. MSEW mice showed reduced intensity of parvalbumin as well as increased PNN intensity around parvalbumin-positive interneurons in the vHIP. We further observed that MSEW increased orthodenticle homeobox protein 2, a transcription factor promoting PNN development, in the choroid plexus, where it is produced, as well as in parvalbumin-positive interneurons, where it is sequestered. CONCLUSIONS These findings raise the possibility of causal links among parvalbumin-positive interneurons, PNNs, orthodenticle homeobox protein 2, and MSEW-induced anxiety and hyperactivity.
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Affiliation(s)
- Sahana Murthy
- Princeton Neuroscience Institute and Department of Psychology, Princeton NJ 08544
| | - Gary A. Kane
- Princeton Neuroscience Institute and Department of Psychology, Princeton NJ 08544
| | - Nicole J. Katchur
- Princeton Neuroscience Institute and Department of Psychology, Princeton NJ 08544
| | - Paula S. Lara Mejia
- Princeton Neuroscience Institute and Department of Psychology, Princeton NJ 08544
| | - Gracious Obiofuma
- Princeton Neuroscience Institute and Department of Psychology, Princeton NJ 08544
| | - Timothy J. Buschman
- Princeton Neuroscience Institute and Department of Psychology, Princeton NJ 08544
| | - Bruce S. McEwen
- Laboratory of Neuroendocrinology, The Rockefeller University, NY, NY 10021
| | - Elizabeth Gould
- Princeton Neuroscience Institute and Department of Psychology, Princeton University, Princeton, New Jersey.
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Manning CE, Eagle AL, Kwiatkowski CC, Achargui R, Woodworth H, Potter E, Ohnishi Y, Leinninger GM, Robison AJ. Hippocampal Subgranular Zone FosB Expression Is Critical for Neurogenesis and Learning. Neuroscience 2019; 406:225-233. [PMID: 30902680 DOI: 10.1016/j.neuroscience.2019.03.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/08/2019] [Accepted: 03/11/2019] [Indexed: 12/13/2022]
Abstract
Neural proliferation in the dentate gyrus (DG) is closely linked with learning and memory, but the transcriptional programming that drives adult proliferation remains incompletely understood. Our lab previously elucidated the critical role of the transcription factor ΔFosB in the dorsal hippocampus (dHPC) in learning and memory, and the FosB gene has been suggested to play a role in neuronal proliferation. However, the subregion-specific and potentially cell-autonomous role of dHPC ΔFosB in neurogenesis-dependent learning has not been studied. Here, we crossed neurotensin receptor-2 (NtsR2) Cre mice, which express Cre within the subgranular zone (SGZ) of dHPC DG, with floxed FosB mice to show that knockout of ΔFosB in hippocampal SGZ neurons reduces antidepressant-induced neurogenesis and impedes hippocampus-dependent learning in the novel object recognition task. Taken together, these data indicate that FosB gene expression in SGZ is necessary for both hippocampal neurogenesis and memory formation.
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Affiliation(s)
- Claire E Manning
- Department of Physiology, Michigan State University, East Lansing, MI, USA 48824
| | - Andrew L Eagle
- Department of Physiology, Michigan State University, East Lansing, MI, USA 48824
| | | | - Ridouane Achargui
- Department of Physiology, Michigan State University, East Lansing, MI, USA 48824
| | - Hillary Woodworth
- Department of Physiology, Michigan State University, East Lansing, MI, USA 48824
| | - Emily Potter
- Department of Physiology, Michigan State University, East Lansing, MI, USA 48824
| | - Yoshinori Ohnishi
- Dept. of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka, Japan; Department of Medical Biophysics and Radiation Biology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Gina M Leinninger
- Department of Physiology, Michigan State University, East Lansing, MI, USA 48824
| | - A J Robison
- Department of Physiology, Michigan State University, East Lansing, MI, USA 48824.
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Schoenfeld TJ, Rhee D, Martin L, Smith JA, Sonti AN, Padmanaban V, Cameron HA. New neurons restore structural and behavioral abnormalities in a rat model of PTSD. Hippocampus 2019; 29:848-861. [PMID: 30865372 DOI: 10.1002/hipo.23087] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 01/24/2019] [Accepted: 02/20/2019] [Indexed: 12/19/2022]
Abstract
Post-traumatic stress disorder (PTSD) has been associated with anxiety, memory impairments, enhanced fear, and hippocampal volume loss, although the relationship between these changes remain unknown. Single-prolonged stress (SPS) is a model for PTSD combining three forms of stress (restraint, swim, and anesthesia) in a single session that results in prolonged behavioral effects. Using pharmacogenetic ablation of adult neurogenesis in rats, we investigated the role of new neurons in the hippocampus in the long-lasting structural and behavioral effects of SPS. Two weeks after SPS, stressed rats displayed increased anxiety-like behavior and decreased preference for objects in novel locations regardless of the presence or absence of new neurons. Chronic stress produced by daily restraint for 2 or 6 hr produced similar behavioral effects that were also independent of ongoing neurogenesis. At a longer recovery time point, 1 month after SPS, rats with intact neurogenesis had normalized, showing control levels of anxiety-like behavior. However, GFAP-TK rats, which lacked new neurons, continued to show elevated anxiety-like behavior and enhanced serum corticosterone response to anxiogenic experience. Volume loss in ventral CA1 region of the hippocampus paralleled increases in anxiety-like behavior, occurring in all rats exposed to SPS at the early time point and only rats lacking adult neurogenesis at the later time point. In chronic stress experiments, volume loss occurred broadly throughout the dentate gyrus and CA1 after 6-hr daily stress but was not apparent in any hippocampal subregion after 2-hr daily stress. No effect of SPS was seen on cell proliferation in the dentate gyrus, but the survival of young neurons born a week after stress was decreased. Together, these data suggest that new neurons are important for recovery of normal behavior and hippocampal structure following a strong acute stress and point to the ventral CA1 region as a potential key mediator of stress-induced anxiety-like behavior.
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Affiliation(s)
- Timothy J Schoenfeld
- Section on Neuroplasticity, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Diane Rhee
- Section on Neuroplasticity, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Laura Martin
- Section on Neuroplasticity, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Jesse A Smith
- Section on Neuroplasticity, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Anup N Sonti
- Section on Neuroplasticity, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Varun Padmanaban
- Section on Neuroplasticity, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Heather A Cameron
- Section on Neuroplasticity, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
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Bird CW, Baculis BC, Mayfield JJ, Chavez GJ, Ontiveros T, Paine DJ, Marks AJ, Gonzales AL, Ron D, Valenzuela CF. The brain-derived neurotrophic factor VAL68MET polymorphism modulates how developmental ethanol exposure impacts the hippocampus. GENES, BRAIN, AND BEHAVIOR 2019; 18:e12484. [PMID: 29691979 PMCID: PMC6291361 DOI: 10.1111/gbb.12484] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 04/03/2018] [Accepted: 04/18/2018] [Indexed: 12/19/2022]
Abstract
Prenatal exposure to alcohol causes a wide range of deficits known as fetal alcohol spectrum disorders (FASDs). Many factors determine vulnerability to developmental alcohol exposure including timing and pattern of exposure, nutrition and genetics. Here, we characterized how a prevalent single nucleotide polymorphism in the human brain-derived neurotrophic factor (BDNF) gene (val66met) modulates FASDs severity. This polymorphism disrupts BDNF's intracellular trafficking and activity-dependent secretion, and has been linked to increased incidence of neuropsychiatric disorders such as depression and anxiety. We hypothesized that developmental ethanol (EtOH) exposure more severely affects mice carrying this polymorphism. We used transgenic mice homozygous for either valine (BDNFval/val ) or methionine (BDNFmet/met ) in residue 68, equivalent to residue 66 in humans. To model EtOH exposure during the second and third trimesters of human pregnancy, we exposed mice to EtOH in vapor chambers during gestational days 12 to 19 and postnatal days 2 to 9. We found that EtOH exposure reduces cell layer volume in the dentate gyrus and the CA1 hippocampal regions of BDNFmet/met but not BDNFval/val mice during the juvenile period (postnatal day 15). During adulthood, EtOH exposure reduced anxiety-like behavior and disrupted trace fear conditioning in BDNFmet/met mice, with most effects observed in males. EtOH exposure reduced adult neurogenesis only in the ventral hippocampus of BDNFval/val male mice. These studies show that the BDNF val66met polymorphism modulates, in a complex manner, the effects of developmental EtOH exposure, and identify a novel genetic risk factor that may regulate FASDs severity in humans.
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Affiliation(s)
- Clark W. Bird
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, U.S.A
| | - Brian C. Baculis
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, U.S.A
| | - Jacob J. Mayfield
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, U.S.A
| | - Glenna J. Chavez
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, U.S.A
| | - Tiahna Ontiveros
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, U.S.A
| | - Dana J. Paine
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, U.S.A
| | - Aaron J. Marks
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, U.S.A
| | - Alicia L. Gonzales
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, U.S.A
| | - Dorit Ron
- Department of Neurology, University of California, San Francisco, San Francisco, California, U.S.A
| | - C. Fernando Valenzuela
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, U.S.A
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Leeson HC, Chan-Ling T, Lovelace MD, Brownlie JC, Gu BJ, Weible MW. P2X7 receptor signaling during adult hippocampal neurogenesis. Neural Regen Res 2019; 14:1684-1694. [PMID: 31169175 PMCID: PMC6585562 DOI: 10.4103/1673-5374.257510] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Neurogenesis is a persistent and essential feature of the adult mammalian hippocampus. Granular neurons generated from resident pools of stem or progenitor cells provide a mechanism for the formation and consolidation of new memories. Regulation of hippocampal neurogenesis is complex and multifaceted, and numerous signaling pathways converge to modulate cell proliferation, apoptosis, and clearance of cellular debris, as well as synaptic integration of newborn immature neurons. The expression of functional P2X7 receptors in the central nervous system has attracted much interest and the regulatory role of this purinergic receptor during adult neurogenesis has only recently begun to be explored. P2X7 receptors are exceptionally versatile: in their canonical role they act as adenosine triphosphate-gated calcium channels and facilitate calcium-signaling cascades exerting control over the cell via calcium-encoded sensory proteins and transcription factor activation. P2X7 also mediates transmembrane pore formation to regulate cytokine release and facilitate extracellular communication, and when persistently stimulated by high extracellular adenosine triphosphate levels large P2X7 pores form, which induce apoptotic cell death through cytosolic ion dysregulation. Lastly, as a scavenger receptor P2X7 directly facilitates phagocytosis of the cellular debris that arises during neurogenesis, as well as during some disease states. Understanding how P2X7 receptors regulate the physiology of stem and progenitor cells in the adult hippocampus is an important step towards developing useful therapeutic models for regenerative medicine. This review considers the relevant aspects of adult hippocampal neurogenesis and explores how P2X7 receptor activity may influence the molecular physiology of the hippocampus, and neural stem and progenitor cells.
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Affiliation(s)
- Hannah C Leeson
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland; Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
| | - Tailoi Chan-Ling
- Discipline of Anatomy and Histology, School of Medical Science; Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Michael D Lovelace
- Discipline of Anatomy and Histology, School of Medical Science, The University of Sydney; Applied Neurosciences Program, Peter Duncan Neurosciences Research Unit, St. Vincent's Centre for Applied Medical Research; Faculty of Medicine, St. Vincent's Clinical School, University of New South Wales Sydney, Sydney, New South Wales, Australia
| | - Jeremy C Brownlie
- School of Environment and Science, Griffith University, Brisbane, Queensland, Australia
| | - Ben J Gu
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Michael W Weible
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland; Bosch Institute, The University of Sydney, Sydney, New South Wales; School of Environment and Science, Griffith University, Brisbane, Queensland, Australia
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Goode TD, Maren S. Common neurocircuitry mediating drug and fear relapse in preclinical models. Psychopharmacology (Berl) 2019; 236:415-437. [PMID: 30255379 PMCID: PMC6373193 DOI: 10.1007/s00213-018-5024-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 09/03/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND Comorbidity of anxiety disorders, stressor- and trauma-related disorders, and substance use disorders is extremely common. Moreover, therapies that reduce pathological fear and anxiety on the one hand, and drug-seeking on the other, often prove short-lived and are susceptible to relapse. Considerable advances have been made in the study of the neurobiology of both aversive and appetitive extinction, and this work reveals shared neural circuits that contribute to both the suppression and relapse of conditioned responses associated with trauma or drug use. OBJECTIVES The goal of this review is to identify common neural circuits and mechanisms underlying relapse across domains of addiction biology and aversive learning in preclinical animal models. We focus primarily on neural circuits engaged during the expression of relapse. KEY FINDINGS After extinction, brain circuits involving the medial prefrontal cortex and hippocampus come to regulate the expression of conditioned responses by the amygdala, bed nucleus of the stria terminalis, and nucleus accumbens. During relapse, hippocampal projections to the prefrontal cortex inhibit the retrieval of extinction memories resulting in a loss of inhibitory control over fear- and drug-associated conditional responding. CONCLUSIONS The overlapping brain systems for both fear and drug memories may explain the co-occurrence of fear and drug-seeking behaviors.
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Affiliation(s)
- Travis D Goode
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, 301 Old Main Dr., College Station, TX, 77843-3474, USA
| | - Stephen Maren
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, 301 Old Main Dr., College Station, TX, 77843-3474, USA.
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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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Huckleberry KA, Shue F, Copeland T, Chitwood RA, Yin W, Drew MR. Dorsal and ventral hippocampal adult-born neurons contribute to context fear memory. Neuropsychopharmacology 2018; 43:2487-2496. [PMID: 29941977 PMCID: PMC6180107 DOI: 10.1038/s41386-018-0109-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/06/2018] [Accepted: 05/29/2018] [Indexed: 12/16/2022]
Abstract
The hippocampus contains one of the few neurogenic niches within the adult brain-the subgranular zone of the dentate gyrus. The functional significance of adult-born neurons in this region has been characterized using context fear conditioning, a Pavlovian paradigm in which animals learn to associate a location with danger. Ablation or silencing of adult-born neurons impairs both acquisition and recall of contextual fear conditioning, suggesting that these neurons contribute importantly to hippocampal memory. Lesion studies indicate that CFC depends on neural activity in both the dorsal and ventral hippocampus, subregions with unique extrahippocampal connectivity and behavioral functions. Because most studies of adult neurogenesis have relied on methods that permanently ablate neurogenesis throughout the entire hippocampus, little is known about how the function of adult-born neurons varies along the dorsal-ventral axis. Using a Nestin-CreERT2 mouse line to target the optogenetic silencer Archaerhodopsin to adult-born neurons, we compared the contribution of dorsal and ventral adult-born neurons to acquisition, recall, and generalization of CFC. Acquisition of CFC was impaired when either dorsal or ventral adult-born neurons were silenced during training. Silencing dorsal or ventral adult-born neurons during test sessions decreased context-evoked freezing but did not impair freezing in a hippocampus-independent tone-shock freezing paradigm. Silencing adult-born neurons modestly reduced generalization of fear. Our data indicate that adult-born neurons in the dorsal and ventral hippocampus contribute to both memory acquisition and recall. The comparatively large behavioral effects of silencing a small number of adult-born neurons suggest that these neurons make a unique and powerful contribution to hippocampal function.
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Affiliation(s)
- Kylie A Huckleberry
- Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
| | - Francis Shue
- Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
| | - Taylor Copeland
- Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
| | - Raymond A Chitwood
- Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
| | - Weiling Yin
- Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX, USA
| | - Michael R Drew
- Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX, USA.
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48
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Hippocampal neural progenitor cells play a distinct role in fear memory retrieval in male and female CIE rats. Neuropharmacology 2018; 143:239-249. [PMID: 30273595 DOI: 10.1016/j.neuropharm.2018.09.045] [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] [Received: 04/22/2018] [Revised: 09/12/2018] [Accepted: 09/27/2018] [Indexed: 12/24/2022]
Abstract
Adult male and female GFAP-TK transgenic rats experienced six weeks of chronic intermittent ethanol vapor inhalation (CIE). During the last week of CIE, a subset of male and female TK rats were fed with Valcyte to ablate neural progenitor cells (NPCs). Seventy-two hours after CIE cessation, all CIE and age-matched ethanol naïve controls experienced auditory trace fear conditioning (TFC). Twenty-four hours later all animals were tested for cue-mediated retrieval in the fear context. Adult male CIE rats showed a significant burst in NPCs paralleled by reduction in fear retrieval compared to naïve controls and Valcyte treated CIE rats. Adult female CIE rats did not show a burst in NPCs and showed similar fear retrieval compared to naïve controls and Valcyte treated CIE rats, indicating that CIE-mediated impairment in fear memory and its regulation by NPCs was sex dependent. Valcyte significantly reduced Ki-67 and NeuroD labeled cells in the dentate gyrus (DG) in both sexes, demonstrating a role for NPCs in reduced fear retrieval in males. Valcyte prevented adaptations in GluN2A receptor expression and synaptoporin density in the DG in males, indicating that NPCs contributed to alterations in plasticity-related proteins and mossy fiber projections that were associated with reduced fear retrieval. These data suggest that DG NPCs born during withdrawal and early abstinence from CIE are aberrant, and could play a role in weakening long-term memory consolidation dependent on the hippocampus.
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49
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Karlsson RM, Wang AS, Sonti AN, Cameron HA. Adult neurogenesis affects motivation to obtain weak, but not strong, reward in operant tasks. Hippocampus 2018; 28:512-522. [PMID: 29663595 DOI: 10.1002/hipo.22950] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 03/27/2018] [Accepted: 04/05/2018] [Indexed: 12/17/2022]
Abstract
Decreased motivation to seek rewards is a key feature of mood disorders that correlates with severity and treatment outcome. This anhedonia, or apathy, likely reflects impairment in reward circuitry, but the specific neuronal populations controlling motivation are unclear. Granule neurons generated in the adult hippocampus have been implicated in mood disorders, but are not generally considered as part of reward circuits. We investigated a possible role of these new neurons in motivation to work for food and sucrose rewards in operant conditioning tasks using GFAP-TK pharmacogenetic ablation of adult neurogenesis in both rats and mice. Rats and mice lacking adult neurogenesis showed normal lever press responding during fixed ratio training, reward devaluation, and Pavlovian Instrumental Transfer, suggesting no impairment in learning. However, on an exponentially progressive ratio schedule, or when regular chow was freely available in the testing chamber, TK rats and mice showed less effort to gain sucrose tablets. When working for balanced food tablets, which rats and mice of both genotypes strongly preferred over sucrose, the genotype effects on behavior were lost. This decrease in effort under conditions of low reward suggests that loss of adult neurogenesis decreases motivation to seek reward in a manner that may model behavioral apathy.
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Affiliation(s)
- Rose-Marie Karlsson
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892
| | - Alice S Wang
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892
| | - Anup N Sonti
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892
| | - Heather A Cameron
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892
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50
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Cavalli J, Ruttorf M, Pahi MR, Zidda F, Flor H, Nees F. Oxytocin differentially modulates pavlovian cue and context fear acquisition. Soc Cogn Affect Neurosci 2018; 12:976-983. [PMID: 28402515 PMCID: PMC5472122 DOI: 10.1093/scan/nsx028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 03/01/2017] [Indexed: 12/11/2022] Open
Abstract
Fear acquisition and extinction have been demonstrated as core mechanisms for the development and maintenance of mental disorders, with different contributions of processing cues vs contexts. The hypothalamic peptide oxytocin (OXT) may have a prominent role in this context, as it has been shown to affect fear learning. However, investigations have focused on cue conditioning, and fear extinction. Its differential role for cue and context fear acquisition is still not known. In a randomized, double-blind, placebo (PLC)-controlled design, we administered an intranasal dose of OXT or PLC before the acquisition of cue and context fear conditioning in healthy individuals (n = 52), and assessed brain responses, skin conductance responses and self-reports (valence/arousal/contingency). OXT compared with PLC significantly induced decreased responses in the nucleus accumbens during early cue and context acquisition, and decreased responses of the anterior cingulate cortex and insula during early as well as increased hippocampal response during late context, but not cue acquisition. The OXT group additionally showed significantly higher arousal in late cue and context acquisition. OXT modulates various aspects of cue and context conditioning, which is relevant from a mechanism-based perspective and might have implications for the treatment of fear and anxiety.
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Affiliation(s)
- Juliana Cavalli
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Michaela Ruttorf
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Mario Rosero Pahi
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Francesca Zidda
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Herta Flor
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Frauke Nees
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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