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Copenhaver AE, LeGates TA. Sex-Specific Mechanisms Underlie Long-Term Potentiation at Hippocampus→Medium Spiny Neuron Synapses in the Medial Shell of the Nucleus Accumbens. J Neurosci 2024; 44:e0100242024. [PMID: 38806250 PMCID: PMC11223474 DOI: 10.1523/jneurosci.0100-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 05/16/2024] [Accepted: 05/21/2024] [Indexed: 05/30/2024] Open
Abstract
Sex differences have complicated our understanding of the neurobiological basis of many behaviors that are key for survival. As such, continued elucidation of the similarities and differences between sexes is necessary to gain insight into brain function and vulnerability. The connection between the hippocampus (Hipp) and nucleus accumbens (NAc) is a crucial site where modulation of neuronal activity mediates reward-related behavior. Our previous work demonstrated that long-term potentiation (LTP) of Hipp→NAc synapses is rewarding, and mice can establish learned associations between LTP of these synapses and the contextual environment in which LTP occurred. Here, we investigated sex differences in the mechanisms underlying Hipp→NAc LTP using whole-cell electrophysiology and pharmacology. We observed similarities in basal synaptic strength between males and females and found that LTP occurs postsynaptically with similar magnitudes in both sexes. However, key sex differences emerged as LTP in males required NMDA receptors (NMDAR), whereas LTP in females utilized an NMDAR-independent mechanism involving L-type voltage-gated Ca2+ channels (VGCCs) and estrogen receptor α (ERα). We also uncovered sex-similar features as LTP in both sexes depended on CaMKII activity and occurred independently of dopamine-1 receptor (D1R) activation. Our results have elucidated sex-specific molecular mechanisms for LTP in an integral pathway that mediates reward-related behaviors, emphasizing the importance of considering sex as a variable in mechanistic studies. Continued characterization of sex-specific mechanisms underlying plasticity will offer novel insight into the neurophysiological basis of behavior, with significant implications for understanding how diverse processes mediate behavior and contribute to vulnerability to developing psychiatric disorders.
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Affiliation(s)
- Ashley E Copenhaver
- Department of Biological Sciences, University of Maryland, Baltimore County (UMBC), Baltimore, Maryland 21250
| | - Tara A LeGates
- Department of Biological Sciences, University of Maryland, Baltimore County (UMBC), Baltimore, Maryland 21250
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, Maryland 21201
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Gupta RS, Light GA, Simmons AN, Harlé KM, Stout DM. Sex moderates the effect of anhedonia on parietal alpha asymmetry. J Psychiatr Res 2024; 177:97-101. [PMID: 39002532 DOI: 10.1016/j.jpsychires.2024.06.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 06/23/2024] [Accepted: 06/28/2024] [Indexed: 07/15/2024]
Abstract
Anhedonia, a transdiagnostic symptom present in many neuropsychiatric disorders, differs in males and females. Parietal EEG alpha asymmetry is associated with reduced arousal and low positive emotionality, and is, therefore, a promising neurophysiologic biomarker of anhedonia. To date, however, no prior studies have determined whether this measure captures sex differences in anhedonic expression. This preliminary study (N = 36) investigated whether anhedonia severity is associated with EEG resting-state parietal alpha asymmetry in adults and whether sex moderates this relationship. Results showed that there was a significant moderating effect of sex such that, only for females, higher levels of anhedonia were associated with increased parietal alpha asymmetry. These findings suggest that parietal alpha asymmetry is a promising biomarker of anhedonia severity in female adults and reinforces the need to account for sex differences in future research.
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Affiliation(s)
- Resh S Gupta
- Department of Psychological & Brain Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Gregory A Light
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA; Desert Pacific Mental Illness Research Education and Clinical Center, La Jolla, CA, USA
| | - Alan N Simmons
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA; Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, 92161, USA
| | - Katia M Harlé
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA; Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, 92161, USA
| | - Daniel M Stout
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA; Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, 92161, USA
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Campbell HM, Guo JD, Kuhn CM. Applying the Research Domain Criteria to Rodent Studies of Sex Differences in Chronic Stress Susceptibility. Biol Psychiatry 2024:S0006-3223(24)01351-9. [PMID: 38821193 DOI: 10.1016/j.biopsych.2024.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 04/27/2024] [Accepted: 05/17/2024] [Indexed: 06/02/2024]
Abstract
Women have a 2-fold increased rate of stress-associated psychiatric disorders such as depression and anxiety, but the mechanisms that underlie this increased susceptibility remain incompletely understood. Historically, female subjects were excluded from preclinical studies and clinical trials. Additionally, chronic stress paradigms used to study psychiatric pathology in animal models were developed for use in males. However, recent changes in National Institutes of Health policy encourage inclusion of female subjects, and considerable work has been performed in recent years to understand biological sex differences that may underlie differences in susceptibility to chronic stress-associated psychiatric conditions. Here, we review the utility as well as current challenges of using the framework of the National Institute of Mental Health's Research Domain Criteria as a transdiagnostic approach to study sex differences in rodent models of chronic stress including recent progress in the study of sex differences in the neurobehavioral domains of negative valence, positive valence, cognition, social processes, and arousal.
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Affiliation(s)
- Hannah M Campbell
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina
| | - Jessica D Guo
- Duke University School of Medicine, Durham, North Carolina
| | - Cynthia M Kuhn
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina; Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina.
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Wang X, Xia Y, Yan R, Sun H, Huang Y, Xia Q, Sheng J, You W, Hua L, Tang H, Yao Z, Lu Q. Sex differences in anhedonia in bipolar depression: a resting-state fMRI study. Eur Arch Psychiatry Clin Neurosci 2024:10.1007/s00406-024-01765-4. [PMID: 38558145 DOI: 10.1007/s00406-024-01765-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 01/13/2024] [Indexed: 04/04/2024]
Abstract
Previous studies about anhedonia symptoms in bipolar depression (BD) ignored the unique role of gender on brain function. This study aims to explore the regional brain neuroimaging features of BD with anhedonia and the sex differences in these patients. The resting-fMRI by applying fractional amplitude of low-frequency fluctuation (fALFF) method was estimated in 263 patients with BD (174 high anhedonia [HA], 89 low anhedonia [LA]) and 213 healthy controls. The effects of two different factors in patients with BD were analyzed using a 3 (group: HA, LA, HC) × 2 (sex: male, female) ANOVA. The fALFF values were higher in the HA group than in the LA group in the right medial cingulate gyrus and supplementary motor area. For the sex-by-group interaction, the fALFF values of the right hippocampus, left medial occipital gyrus, right insula, and bilateral medial cingulate gyrus were significantly higher in HA males than in LA males but not females. These results suggested that the pattern of high activation could be a marker of anhedonia symptoms in BD males, and the sex differences should be considered in future studies of BD with anhedonia symptoms.
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Affiliation(s)
- Xiaoqin Wang
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China
| | - Yi Xia
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China
| | - Rui Yan
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China
| | - Hao Sun
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China
- Nanjing Brain Hospital, Medical School of Nanjing University, 22 Hankou Road, Nanjing, 210093, China
| | - Yinghong Huang
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China
- Nanjing Brain Hospital, Medical School of Nanjing University, 22 Hankou Road, Nanjing, 210093, China
| | - Qiudong Xia
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China
| | - Junling Sheng
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China
| | - Wei You
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China
| | - Lingling Hua
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China
| | - Hao Tang
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China
| | - Zhijian Yao
- The Affiliated Brain Hospital of Nanjing Medical University, 264 Guangzhou Road, Nanjing, 210029, China.
- Nanjing Brain Hospital, Medical School of Nanjing University, 22 Hankou Road, Nanjing, 210093, China.
- School of Biological Sciences and Medical Engineering, Southeast University, 2 sipailou, Nanjing, 210096, China.
| | - Qing Lu
- School of Biological Sciences and Medical Engineering, Southeast University, 2 sipailou, Nanjing, 210096, China.
- Child Development and Learning Science, Key Laboratory of Ministry of Education, Nanjing, 210096, China.
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Copenhaver AE, LeGates TA. Sex-specific mechanisms underlie long-term potentiation at hippocampus-nucleus accumbens synapses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.15.575709. [PMID: 38293132 PMCID: PMC10827060 DOI: 10.1101/2024.01.15.575709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Sex differences have complicated our understanding of the neurobiological basis of many behaviors that are key for survival. As such, continued elucidation of the similarities and differences between sexes is necessary in order to gain insight into brain function and vulnerability. The connection between the hippocampus (Hipp) and nucleus accumbens (NAc) is a crucial site where modulation of neuronal activity mediates reward-related behavior. Our previous work demonstrated that long-term potentiation (LTP) of Hipp-NAc synapses is rewarding, and that mice can make learned associations between LTP of these synapses and the contextual environment in which LTP occurred. Here, we investigate sex differences in the mechanisms underlying Hipp-NAc LTP using whole-cell electrophysiology and pharmacology. We found that males and females display similar magnitudes of Hipp-NAc LTP which occurs postsynaptically. However, LTP in females requires L-type voltage-gated Ca 2+ channels (VGCC) for postsynaptic Ca 2+ influx, while males rely on NMDA receptors (NMDAR). Additionally, females require estrogen receptor α (ERα) activity for LTP while males do not. These differential mechanisms converge as LTP in both sexes depends on CAMKII activity and occurs independently of dopamine-1 receptor (D1R) activation. Our results have elucidated sex-specific molecular mechanisms for LTP in an integral excitatory pathway that mediates reward-related behaviors, emphasizing the importance of considering sex as a variable in mechanistic studies. Continued characterization of sex-specific mechanisms underlying plasticity will offer novel insight into the neurophysiological basis of behavior, with significant implications for understanding how diverse processes mediate behavior and contribute to vulnerability to developing psychiatric disorders. SIGNIFICANCE STATEMENT Strengthening of Hipp-NAc synapses drives reward-related behaviors. Male and female mice have similar magnitudes of long-term potentiation (LTP) and both sexes have a predicted postsynaptic locus of plasticity. Despite these similarities, we illustrate here that sex-specific molecular mechanisms are used to elicit LTP. Given the bidirectional relationship between Hipp-NAc synaptic strength in mediating reward-related behaviors, the use of distinct molecular mechanisms may explain sex differences observed in stress susceptibility or response to rewarding stimuli. Discovery and characterization of convergent sex differences provides mechanistic insight into the sex-specific function of Hipp-NAc circuitry and has widespread implications for circuits mediating learning and reward-related behavior.
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