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Costello A, Linning-Duffy K, Vandenbrook C, Lonstein JS, Yan L. Effects of bright light therapy on neuroinflammatory and neuroplasticity markers in a diurnal rodent model of Seasonal Affective Disorder. Ann Med 2023; 55:2249015. [PMID: 37625385 PMCID: PMC10461522 DOI: 10.1080/07853890.2023.2249015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/09/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
BACKGROUND Bright light therapy (BLT) is widely used for treating Seasonal Affective Disorder (SAD). However, the neural mechanisms underlying the therapeutic effects of BLT remain largely unexplored. The present study used a diurnal rodent (Nile grass rats; Arvicanthis niloticus) to test the hypothesis that the therapeutic effects of BLT could be, in part, due to reduced neuroinflammation and/or enhanced neuroplasticity. Our previous research has demonstrated that compared to grass rats housed in a summer-like daytime bright light condition (1000 lux), those housed in a winter-like daytime dim light condition (50 lux) showed increased depression- and anxiety-like behaviours, as well as impaired sociosexual behaviours and spatial memory, similar to what is observed in patients suffering from SAD. MATERIALS AND METHODS In the present study, male and female grass rats were housed under the winter-like dim daytime light condition (lights on 600-1800 hr, 50 lux). The experimental groups received daily 1-h early morning BLT from 0600-0700 using full-spectrum light (10,000 lux), while the control groups received narrowband red light (λmax, 780 nm). Following 4 weeks of treatment, the expression of several neuroinflammatory or plasticity markers was examined in the medial prefrontal cortex (mPFC), basolateral amygdala (BLA), and the CA1 of the dorsal hippocampus. RESULTS For the neuroinflammatory markers, BLT reduced TNF-α in the BLA of females, and upregulated CD11b in the mPFC and IL6 in the BLA in males. For the neuroplasticity markers, BLT downregulated BDNF in the CA1 and TrkB in all three brain regions in females but upregulated BDNF in the BLA and CA1 in males. CONCLUSIONS These results indicate that the therapeutic effects of BLT on sleep, mood, and cognition may be attributed in part to mechanisms involving neuroinflammation and neuroplasticity in corticolimbic brain regions. Moreover, these effects appear to vary between sexes.
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Affiliation(s)
| | | | | | - Joseph S. Lonstein
- Department of Psychology, MI State University, MI, USA
- Neuroscience Program, Michigan State University, MI, USA
| | - Lily Yan
- Department of Psychology, MI State University, MI, USA
- Neuroscience Program, Michigan State University, MI, USA
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So LY, Miller JE. Social context-dependent singing alters molecular markers of synaptic plasticity signaling in finch basal ganglia Area X. Behav Brain Res 2020; 398:112955. [PMID: 33031871 DOI: 10.1016/j.bbr.2020.112955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/14/2020] [Accepted: 09/30/2020] [Indexed: 12/23/2022]
Abstract
Vocal communication is a crucial skill required throughout life. However, there is a critical gap in our understanding of the underlying molecular brain mechanisms, thereby motivating our use of the zebra finch songbird model. Adult male zebra finches show differences in neural activity patterns in song-dedicated brain nuclei when they sing in two distinct social contexts: a male singing by himself (undirected, UD) and a male singing to a female (female-directed, FD). In our prior work, we showed that in song-dedicated basal ganglia Area X, protein levels of a N-methyl-D-aspartate receptor subtype 2B (NMDAR2B) increased with more UD song and decreased with more FD song. We hypothesized that molecules downstream of this receptor would show differential protein expression levels in Area X between UD and FD song. Specifically, we investigated calcium/calmodulin dependent protein kinase II beta (CaMKIIB), homer scaffold protein 1 (HOMER1), serine/threonine protein kinase (Akt), and mechanistic target of rapamycin kinase (mTOR) following singing and non-singing states in Area X. We show relationships between social context and protein levels. HOMER1 protein levels decreased with time spent singing FD song, and mTOR protein levels decreased with the amount of and time spent singing FD song. For both HOMER1 and mTOR, there were no differences with the amount of UD song. With time spent singing UD, CaMKIIB protein levels trended in a U-shaped curve whereas Akt protein levels trended down. Both molecules showed no change with FD song. Our results support differential involvement of molecules in synaptic plasticity pathways between UD and FD song behaviors.
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Affiliation(s)
- Lisa Y So
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States; Department of Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States
| | - Julie E Miller
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States; Department of Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States; Department of Speech, Language, and Hearing Sciences, University of Arizona, Speech, Language, and Hearing Sciences Building, Tucson, AZ, 85721, United States.
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Nkomozepi P, Mazengenya P, Ihunwo AO. Quantitative analysis of age and life-history stage related changes in DCX expression in the male Japanese quail (Cortunix japonica) telencephalon. Int J Dev Neurosci 2019; 74:38-48. [PMID: 30890437 DOI: 10.1016/j.ijdevneu.2019.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/23/2019] [Accepted: 03/11/2019] [Indexed: 12/22/2022] Open
Abstract
Most avian neurogenesis studies focused on the song control system and little attention has been given to non-song birds such as the Japanese quail. However, the only few neurogenesis studies in quails mainly focused on the sex steroid sensitive areas of the brain such as the medial preoptic and lateral septal nuclei. Despite the important role the quail telencephalon plays in filial imprinting and passive avoidance learning, neurogenesis in this structure has been completely overlooked. The aim of this study was therefore to quantitatively determine how DCX expression in the Japanese quail telencephalon changes with post hatching age (3-12 weeks) and life history stage. In this study, DCX was used as a proxy for neuronal incorporation. Bipolar and multipolar DCX immunoreactive cells were observed in the entire telencephalon except for the entopallium and arcopallium. In addition, DCX expression in all the eight telencephalic areas quantified was strongly negatively correlated with post-hatching age. Furthermore, numbers of bipolar and multipolar DCX immunoreactive cells were higher in the juvenile compared to subadult and adult quails. In conclusion, neuronal incorporation in the quail telencephalon is widespread but it declines with post hatching age. In addition, the most dramatic decline in neuronal incorporation in the telencephalic areas quantified takes place just after the birds have attained sexual maturity.
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Affiliation(s)
- Pilani Nkomozepi
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa; Department of Human Anatomy & Physiology, University of Johannesburg, Cnr Siemert and Beit Streets, Doornfontein, Johannesburg, 2094, South Africa
| | - Pedzisai Mazengenya
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa.
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BDNF, Brain, and Regeneration: Insights from Zebrafish. Int J Mol Sci 2018; 19:ijms19103155. [PMID: 30322169 PMCID: PMC6214035 DOI: 10.3390/ijms19103155] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 12/17/2022] Open
Abstract
Zebrafish (Danio rerio) is a teleost fish widely accepted as a model organism for neuroscientific studies. The adults show common basic vertebrate brain structures, together with similar key neuroanatomical and neurochemical pathways of relevance to human diseases. However, the brain of adult zebrafish possesses, differently from mammals, intense neurogenic activity, which can be correlated with high regenerative properties. Brain derived neurotrophic factor (BDNF), a member of the neurotrophin family, has multiple roles in the brain, due also to the existence of several biologically active isoforms, that interact with different types of receptors. BDNF is well conserved in the vertebrate evolution, with the primary amino acid sequences of zebrafish and human BDNF being 91% identical. Here, we review the available literature regarding BDNF in the vertebrate brain and the potential involvement of BDNF in telencephalic regeneration after injury, with particular emphasis to the zebrafish. Finally, we highlight the potential of the zebrafish brain as a valuable model to add new insights on future BDNF studies.
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Sex-specific differences in corticosterone secretion, behavioral phenotypes and expression of TrkB.T1 and TrkB.FL receptor isoforms: Impact of systemic TrkB inhibition and combinatory stress exposure in adolescence. Prog Neuropsychopharmacol Biol Psychiatry 2018; 86:10-23. [PMID: 29753050 DOI: 10.1016/j.pnpbp.2018.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 04/04/2018] [Accepted: 05/08/2018] [Indexed: 12/12/2022]
Abstract
Stress exposure has been implicated in the development of mood disorders, although little is known about the lasting effects of repeated stress during the adolescent period on sex-specific differences in endocrine and plasticity-signaling responses in adulthood. Using a 10-day combinatory stress paradigm (postnatal day (PND) 26 to 35), we examined sex-specific impact of adolescent stress and inhibition of tyrosine-related kinase B (TrkB) receptor (ANA-12; 0.5 mg/kg, i.p.) on 1) adolescent blood corticosterone levels, 2) adult locomotion and anxiety-like behavior, and 3) region-specific differences in endogenous TrkB full-length (TrkB.FL) and truncated (TrkB.T1) receptor isoforms. Blood collected on days 1, 5 and 10 revealed elevated basal and stress-induced CORT secretion in females compared to males, while ANA-12 attenuated CORT elevations post stress in both sexes. As adults, all females exhibited higher locomotor and exploratory activity than males in the open field test and elevated plus maze, and differences were comparable in the forced swim within stress-naïve and stress groups. Biochemically, vehicle-treated males showed elevated TrkB.T1 and TrkB.FL compared to vehicle-treated females in the PFC, hippocampus and NAc, and levels were consistently attenuated by ANA-12 treatment in non-stress males. With regards to stress exposure, expression of both isoforms was strongly down-regulated in the NAc of males only and was associated with increased TrkB.T1 in the PFC. ANA-12 enhanced expression in females, independent of stress exposure, compared to vehicle-treated counterparts, expression being increased for TrkB.T1 versus TrkB.FL and magnitude of the changes being region-specific. In contrast, ANA-12 effects in stressed males were restricted to inhibition of both isoforms in the hippocampus. Together, our findings support that TrkB activation, contingent on stress exposure, differentially affects TrkB isoform regulation during adulthood. Sex-specific biochemical responses at delayed intervals following adolescent stress exposure further support the need to include the sex variable in animal models.
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Brague JC, Zinn CR, Granot DY, Feathers CT, Swann JM. TrkB is necessary for male copulatory behavior in the Syrian Hamster (Mesocricetus auratus). Horm Behav 2018; 97:162-169. [PMID: 29092774 DOI: 10.1016/j.yhbeh.2017.10.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 10/23/2017] [Accepted: 10/27/2017] [Indexed: 11/29/2022]
Abstract
The magnocellular medial preoptic nucleus (MPN mag), a subdivision of the medial preoptic area (MPOA), plays a critical role in the regulation of copulation in the male Syrian hamster; in part by mediating the effects of gonadal steroids. For example, ablation of the MPN mag eliminates mating and testosterone placed in the MPN mag restores mating in castrated males. Furthermore, testosterone treatment enhances synaptic density and dendritic spines in the MPN mag. Thus, copulatory behaviors are correlated with increases in synaptic morphology in the MPN mag. As brain derived neurotrophic factor (BDNF) and its receptor, tyrosine receptor kinase-B (TrkB), effect neuronal growth and synaptic plasticity, this study explored the role of TrkB and BDNF in mediating testosterone's effects on the MPN mag and behavior. Testosterone treatment increased BDNF expression and conversely lowered TrkB expression in the MPOA. siRNA-mediated TrkB knockdown in the MPN mag eliminated copulation two-days post injection and the behavior was restored one week later. These data indicate that testosterone influences the expression of BDNF and TrkB in the MPOA and that expression of copulation is dependent on the presence of TrkB. Taken together our findings support a role for TrkB and BDNF in mediating the effects of testosterone on copulatory behavior in the Syrian hamster.
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Affiliation(s)
- Joe C Brague
- Lehigh University, Department of Biological Sciences, Iacocca Hall, 111 Research Dr., Bethlehem, PA 18015, United States..
| | - Clifford R Zinn
- Lehigh University, Department of Biological Sciences, Iacocca Hall, 111 Research Dr., Bethlehem, PA 18015, United States
| | - Dean Y Granot
- Lehigh University, Department of Biological Sciences, Iacocca Hall, 111 Research Dr., Bethlehem, PA 18015, United States
| | - Cameron T Feathers
- Lehigh University, Department of Biological Sciences, Iacocca Hall, 111 Research Dr., Bethlehem, PA 18015, United States
| | - Jennifer M Swann
- Lehigh University, Department of Biological Sciences, Iacocca Hall, 111 Research Dr., Bethlehem, PA 18015, United States..
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Wei YC, Wang SR, Xu XH. Sex differences in brain-derived neurotrophic factor signaling: Functions and implications. J Neurosci Res 2017; 95:336-344. [PMID: 27870405 DOI: 10.1002/jnr.23897] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 07/18/2016] [Accepted: 08/01/2016] [Indexed: 02/03/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) regulates diverse processes such as neuronal survival, differentiation, and plasticity. Accumulating evidence suggests that molecular events that direct sexual differentiation of the brain interact with BDNF signaling pathways. This Mini-Review first examines potential hormonal and epigenetic mechanisms through which sex influences BDNF signaling. We then examine how sex-specific regulation of BDNF signaling supports the development and function of sexually dimorphic neural circuits that underlie male-specific genital reflexes in rats and song production in birds. Finally, we discuss the implications of sex differences in BDNF signaling for gender-biased presentation of neurological and psychiatric diseases such as Alzheimer's disease. Although this Mini-Review focuses on BDNF, we try to convey the general message that sex influences brain functions in complex ways and underscore the requirement for and challenge of expanding research on sex differences in neuroscience. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Yi-Chao Wei
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,University of the Chinese Academy of Sciences, Beijing, China
| | - Shao-Ran Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,University of the Chinese Academy of Sciences, Beijing, China
| | - Xiao-Hong Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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8
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Sexual dimorphic expression of TrkB, TrkB-T1, and BDNF in the medial preoptic area of the Syrian hamster. Brain Res 2017; 1669:122-125. [PMID: 28606780 DOI: 10.1016/j.brainres.2017.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 05/16/2017] [Accepted: 06/06/2017] [Indexed: 12/12/2022]
Abstract
Neurotrophins regulate many aspects of neuronal function and activity. Specifically, the binding of Brain-derived neurotrophic factor (BDNF) to Tyrosine receptor kinase-B (TrkB) or its truncated version, TrkB-T1, can cause growth and differentiation or dominant inhibition of receptor signaling, respectively. There is evidence that these neurotropic effects on nervous tissue, in both the central and peripheral nervous system, behave differently between the sexes. This study used western blots to examine the expression of these neurotrophins in the medial preoptic area (MPOA), a sexually dimorphic region of the hamster brain that controls male sex behavior. We report that TrkB-FL and BDNF show greater expression in male MPOA tissue, when compared to female. On the contrary, TrkB-T1 is expressed in greater abundance in the female MPOA. Our results indicate a clear sexual dimorphism of neurotrophins in the MPOA of the Syrian hamster. Furthermore, the greater expression of TrkB-FL and BDNF in the male MPOA suggests that these neurotrophins could be promoting synaptic growth to facilitate male-typical copulation. In contrast, the greater TrkB-T1 expression in the female MPOA suggests a possible inhibition of synaptic growth, and may contribute to the lack of male-typical copulation. Altogether, our data suggests that neurotrophins may play a larger role sexual differentiation than previously thought.
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9
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Beach LQ, Tang YP, Kerver H, Wade J. Inhibition of TrkB limits development of the zebra finch song system. Brain Res 2016; 1642:467-477. [PMID: 27086969 PMCID: PMC4899271 DOI: 10.1016/j.brainres.2016.04.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 04/12/2016] [Accepted: 04/13/2016] [Indexed: 01/19/2023]
Abstract
Large sexual dimorphisms exist in the zebra finch song system. Masculinization may be mediated by both estradiol and expression of one or more Z-genes (males: ZZ; females: ZW). Roles of the Z-gene tyrosine kinase B (TrkB) in HVC in masculinizing both HVC and one of its targets the robust nucleus of the arcopallium (RA), were tested using siRNA administration in juvenile males at two ages (post-hatching days 15-17 or 25-27). Birds were euthanized 10 days later. Potential interactions or additive effects with estradiol were evaluated by treating males with the estrogen synthesis inhibitor fadrozole. Females treated with estradiol were also exposed to the siRNA at the later age. Local inhibition of TrkB in males of both ages reduced the volume of HVC, an effect due to a change in cell number and not cell size. In the older males, in which the treatment spanned the period when the projection from HVC to RA grows, TrkB inhibition reduced the volume of RA and the relative number of cells within it. TrkB siRNA in HVC decreased the volume of and soma size in the RA of females, and the projection from HVC to RA in both sexes. Estradiol in females masculinized various aspects of the song system, and its effect in masculinizing the volume of RA was decreased by TrkB inhibition. However, effects of fadrozole in males were limited. The data indicate that TrkB is involved in masculinizing the song system, but for most measures it probably does not work in concert with E2.
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Affiliation(s)
- Linda Qi Beach
- Neuroscience Program, Michigan State University, East Lansing, MI, USA 48824-1101
- Department of Psychology, Michigan State University, East Lansing, MI, USA 48824-1101
| | - Yu Ping Tang
- Neuroscience Program, Michigan State University, East Lansing, MI, USA 48824-1101
- Department of Psychology, Michigan State University, East Lansing, MI, USA 48824-1101
| | - Halie Kerver
- Neuroscience Program, Michigan State University, East Lansing, MI, USA 48824-1101
| | - Juli Wade
- Neuroscience Program, Michigan State University, East Lansing, MI, USA 48824-1101
- Department of Psychology, Michigan State University, East Lansing, MI, USA 48824-1101
- Department of Integrative Biology Michigan State University, East Lansing, MI, USA 48824-1101
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Cacialli P, Gueguen MM, Coumailleau P, D’Angelo L, Kah O, Lucini C, Pellegrini E. BDNF Expression in Larval and Adult Zebrafish Brain: Distribution and Cell Identification. PLoS One 2016; 11:e0158057. [PMID: 27336917 PMCID: PMC4918975 DOI: 10.1371/journal.pone.0158057] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 06/09/2016] [Indexed: 12/13/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, has emerged as an active mediator in many essential functions in the central nervous system of mammals. BDNF plays significant roles in neurogenesis, neuronal maturation and/or synaptic plasticity and is involved in cognitive functions such as learning and memory. Despite the vast literature present in mammals, studies devoted to BDNF in the brain of other animal models are scarse. Zebrafish is a teleost fish widely known for developmental genetic studies and is emerging as model for translational neuroscience research. In addition, its brain shows many sites of adult neurogenesis allowing higher regenerative properties after traumatic injuries. To add further knowledge on neurotrophic factors in vertebrate brain models, we decided to determine the distribution of bdnf mRNAs in the larval and adult zebrafish brain and to characterize the phenotype of cells expressing bdnf mRNAs by means of double staining studies. Our results showed that bdnf mRNAs were widely expressed in the brain of 7 days old larvae and throughout the whole brain of mature female and male zebrafish. In adults, bdnf mRNAs were mainly observed in the dorsal telencephalon, preoptic area, dorsal thalamus, posterior tuberculum, hypothalamus, synencephalon, optic tectum and medulla oblongata. By combining immunohistochemistry with in situ hybridization, we showed that bdnf mRNAs were never expressed by radial glial cells or proliferating cells. By contrast, bdnf transcripts were expressed in cells with neuronal phenotype in all brain regions investigated. Our results provide the first demonstration that the brain of zebrafish expresses bdnf mRNAs in neurons and open new fields of research on the role of the BDNF factor in brain mechanisms in normal and brain repairs situations.
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Affiliation(s)
- Pietro Cacialli
- INSERM U1085, Research Institute in Health, Environment and Occupation (IRSET), University of Rennes 1, Rennes, France
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Napoli, Italy
| | - Marie-Madeleine Gueguen
- INSERM U1085, Research Institute in Health, Environment and Occupation (IRSET), University of Rennes 1, Rennes, France
| | - Pascal Coumailleau
- INSERM U1085, Research Institute in Health, Environment and Occupation (IRSET), University of Rennes 1, Rennes, France
| | - Livia D’Angelo
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Napoli, Italy
| | - Olivier Kah
- INSERM U1085, Research Institute in Health, Environment and Occupation (IRSET), University of Rennes 1, Rennes, France
| | - Carla Lucini
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Napoli, Italy
- * E-mail: (EP); (CL)
| | - Elisabeth Pellegrini
- INSERM U1085, Research Institute in Health, Environment and Occupation (IRSET), University of Rennes 1, Rennes, France
- * E-mail: (EP); (CL)
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Wade J. Genetic regulation of sex differences in songbirds and lizards. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150112. [PMID: 26833833 DOI: 10.1098/rstb.2015.0112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2015] [Indexed: 01/06/2023] Open
Abstract
Sex differences in the morphology of neural and peripheral structures related to reproduction often parallel the frequency of particular behaviours displayed by males and females. In a variety of model organisms, these sex differences are organized in development by gonadal steroids, which also act in adulthood to modulate behavioural expression and in some cases to generate parallel anatomical changes on a seasonal basis. Data collected from diverse species, however, suggest that changes in hormone availability are not sufficient to explain sex and seasonal differences in structure and function. This paper pulls together some of this literature from songbirds and lizards and considers the information in the broader context of taking a comparative approach to investigating genetic mechanisms associated with behavioural neuroendocrinology.
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Affiliation(s)
- Juli Wade
- Departments of Psychology and Integrative Biology, Michigan State University, East Lansing, MI 48824, USA
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Tang YP, Wade J. Sex and age differences in brain-derived neurotrophic factor and vimentin in the zebra finch song system: Relationships to newly generated cells. J Comp Neurol 2015; 524:1081-96. [PMID: 26355496 DOI: 10.1002/cne.23893] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/21/2015] [Accepted: 08/26/2015] [Indexed: 12/12/2022]
Abstract
The neural song circuit is enhanced in male compared with female zebra finches due to differential rates of incorporation and survival of cells between the sexes. Two double-label immunohistochemical experiments were conducted to increase the understanding of relationships between newly generated cells (marked with bromodeoxyuridine [BrdU]) and those expressing brain-derived neurotrophic factor (BDNF) and vimentin, a marker for radial glia. The song systems of males and females were investigated at posthatching day 25 during a heightened period of sexual differentiation (following BrdU injections on days 6-10) and in adulthood (following a parallel injection paradigm). In both HVC (proper name) and the robust nucleus of the arcopallium (RA), about half of the BrdU-positive cells expressed BDNF across sexes and ages. Less than 10% of the BDNF-positive cells expressed BrdU, but this percentage was greater in juveniles than adults. Across both brain regions, more BDNF-positive cells were detected in males compared with females. In RA, the number of these cells was also greater in juveniles than adults. In HVC, the average cross-sectional area covered by the vimentin labeling was greater in males than females and in juveniles compared with adults. In RA, more vimentin was detected in juveniles than adults, and within adults it was greater in females. In juveniles only, BrdU-positive cells appeared in contact with vimentin-labeled fibers in HVC, RA, and Area X. Collectively, the results are consistent with roles of BDNF- and vimentin-labeled cells influencing sexually differentiated plasticity of the song circuit.
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Affiliation(s)
- Yu Ping Tang
- Department of Psychology, Michigan State University, East Lansing, Michigan, 48824
| | - Juli Wade
- Neuroscience Program, Michigan State University, East Lansing, Michigan, 48824
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Hui LY, Wang YW, Zhou FL, Ma XC, Yan RZ, Zhang L, Wang QL, Yu X. Association Between MKP-1, BDNF, and Gonadal Hormones with Depression on Perimenopausal Women. J Womens Health (Larchmt) 2015; 25:71-7. [PMID: 26176177 PMCID: PMC4741204 DOI: 10.1089/jwh.2015.5214] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Studies suggest that brain-derived neurotrophic factor (BDNF) exerts effects on the neuronal function of hippocampal neurons and increases hippocampal mitogen-activated protein kinase phosphatase-1 (MKP-1) expression, which causes depressive behaviors in rat or mouse. Here we focus on the change of serum MKP-1, BDNF, testosterone (T), and estradiol (E2) levels, in order to test the hypothesis that dysregulation of MKP-1, BDNF, T, and E2 are associated with depression in perimenopausal women. METHODS Women with depression, after meeting criteria in the International Statistical Classification of Diseases and Related Health Problems, 10th Revision, for mental and behaviural disorders and the 17-item Hamilton Depression Rating Scale (HDRS), were included in the study. Psychosocial data and blood samples were obtained from the subjects in the study, including 38 perimenopausal and 32 young women with depression, 26 healthy control perimenopausal women, and 34 young women. RESULTS Serum MKP-1 levels were higher and T was lower in the women with depression compared to controls (p<0.05), and depressed perimenopausal women exhibited the highest serum MKP-1 levels and lowest T levels. Logistic regression analyses showed that MKP-1 levels were positively correlated with HDRS scores in the women, and T levels were inversely correlated with HDRS scores in the perimenopausal women (p<0.05). CONCLUSIONS This study suggests that high serum MKP-1 levels are associated with depression in women, and this association did not appear to be confounded by age. Further, the results provide evidence of association between depressive symptom severity and increasing serum MKP-1 levels in women, and decreasing T levels in perimenopausal women.
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Affiliation(s)
- Ling-yun Hui
- 1 First Affiliated Hospital, Xi'an Jiaotong University , Xi'an, Shaanxi, China
| | - Ya-wen Wang
- 1 First Affiliated Hospital, Xi'an Jiaotong University , Xi'an, Shaanxi, China
| | - Fu-ling Zhou
- 2 Second Affiliated Hospital, Xi'an Jiaotong University , Xi'an, Shaanxi, China
| | - Xian-cang Ma
- 1 First Affiliated Hospital, Xi'an Jiaotong University , Xi'an, Shaanxi, China
| | - Run-zhi Yan
- 1 First Affiliated Hospital, Xi'an Jiaotong University , Xi'an, Shaanxi, China
| | - Lin Zhang
- 1 First Affiliated Hospital, Xi'an Jiaotong University , Xi'an, Shaanxi, China
| | - Quan-li Wang
- 3 Medical College of Xi'an Jiaotong University , Xi'an, Shaanxi, China
| | - Xuewen Yu
- 1 First Affiliated Hospital, Xi'an Jiaotong University , Xi'an, Shaanxi, China
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14
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Hayley S, Du L, Litteljohn D, Palkovits M, Faludi G, Merali Z, Poulter MO, Anisman H. Gender and brain regions specific differences in brain derived neurotrophic factor protein levels of depressed individuals who died through suicide. Neurosci Lett 2015; 600:12-6. [PMID: 26033186 DOI: 10.1016/j.neulet.2015.05.052] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 05/21/2015] [Accepted: 05/24/2015] [Indexed: 12/22/2022]
Abstract
Considerable evidence supports the view that depressive illness and suicidal behaviour stem from perturbations of neuroplasticity. Presently, we assessed whether depressed individuals who died by suicide displayed brain region-specific changes in brain derived neurotrophic factor (BDNF) and whether such effects varied by gender. Using postmortem samples from non-psychiatric controls and depressed individuals who died by suicide, BDNF protein levels were assessed within the hippocampus and frontopolar prefrontal cortex using Western blot. As expected, BDNF levels were reduced within the frontopolar prefrontal cortex among female depressed suicides; however, males showed no such effect. Contrastingly, within the hippocampus, depressed male but not female suicides displayed significant reductions of BDNF protein levels. Although the mechanisms driving the gender and brain region specific BDNF changes are unclear, our data do support the notion that complex alterations of neuroplasticity may be fundamentally involved in the illness.
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Affiliation(s)
- Shawn Hayley
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada.
| | - Lisheng Du
- University of Ottawa Institute of Mental Health Research, Ottawa, Ontario, Canada
| | - Darcy Litteljohn
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
| | - Miklós Palkovits
- Human Brain Tissue Bank and Laboratory, Semmelweis University, Budapest, Hungary
| | - Gábor Faludi
- Department of Clinical and Theoretical Mental Health, Semmelweis University, Budapest, Hungary
| | - Zul Merali
- University of Ottawa Institute of Mental Health Research, Ottawa, Ontario, Canada
| | - Michael O Poulter
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada
| | - Hymie Anisman
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
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15
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Beach LQ, Wade J. Masculinisation of the zebra finch song system: roles of oestradiol and the Z-chromosome gene tubulin-specific chaperone protein A. J Neuroendocrinol 2015; 27:324-34. [PMID: 25702708 PMCID: PMC4422980 DOI: 10.1111/jne.12267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 02/10/2015] [Accepted: 02/14/2015] [Indexed: 11/26/2022]
Abstract
Robust sex differences in brain and behaviour exist in zebra finches. Only males sing, and forebrain song control regions are more developed in males. The factors driving these differences are not clear, although numerous experiments have shown that oestradiol (E2 ) administered to female hatchlings partially masculinises brain and behaviour. Recent studies suggest that an increased expression of Z-chromosome genes in males (ZZ; females: ZW) might also play a role. The Z-gene tubulin-specific chaperone A (TBCA) exhibits increased expression in the lateral magnocellular nucleus of the anterior nidopallium (LMAN) of juvenile males compared to females; TBCA+ cells project to the robust nucleus of the arcopallium (RA). In the present study, we investigated the role of TBCA and tested hypotheses with respect to the interactive or additive effects of E2 and TBCA. We first examined whether E2 in hatchling zebra finches modulates TBCA expression in the LMAN. It affected neither the mRNA, nor protein in either sex. We then unilaterally delivered TBCA small interfering (si)RNA to the LMAN of developing females treated with E2 or vehicle and males treated with the aromatase inhibitor, fadrozole, or its control. In both sexes, decreasing TBCA in LMAN reduced RA cell number, cell size and volume. It also decreased LMAN volume in females. Fadrozole in males increased LMAN volume and RA cell size. TBCA siRNA delivered to the LMAN also decreased the projection from this brain region to the RA, as indicated by anterograde tract tracing. The results suggest that TBCA is involved in masculinising the song system. However, because no interactions between the siRNA and hormone manipulations were detected, TBCA does not appear to modulate effects of E2 in the zebra finch song circuit.
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Affiliation(s)
- L. Q. Beach
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
| | - J. Wade
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
- Departments of Psychology and Zoology, Michigan State University, East Lansing, MI, USA
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16
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Wessels JM, Leyland NA, Agarwal SK, Foster WG. Estrogen induced changes in uterine brain-derived neurotrophic factor and its receptors. Hum Reprod 2015; 30:925-36. [DOI: 10.1093/humrep/dev018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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17
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Tang YP, Wade J. Tracheosyringeal nerve transection in juvenile male zebra finches decreases BDNF in HVC and RA and the projection between them. Neurosci Lett 2014; 583:26-31. [PMID: 25219377 DOI: 10.1016/j.neulet.2014.09.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 08/27/2014] [Accepted: 09/04/2014] [Indexed: 01/11/2023]
Abstract
This study investigated relationships among disruption of normal vocal learning, brain-derived neurotrophic factor (BDNF), and the morphology of song nuclei in juvenile male zebra finches. The tracheosyringeal nerves were bilaterally transected at post-hatching day 20-25, so that the animals could not properly develop species-typical vocalizations. BDNF protein and the projection from HVC to the robust nucleus of the arcopallium (RA) were quantified during the sensorimotor integration phase of song development. The manipulation decreased the number of BDNF cells in HVC and RA, the volume of these areas defined by BDNF labeling, and the projection from HVC to RA. BDNF was not affected in Area X or the lateral magnocellular nucleus of the anterior nidopallium (LMAN). Thus, inhibition of a bird's ability to practice and/or to hear its own typically developing song specifically diminishes BDNF expression in cortical motor regions required for song production.
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Affiliation(s)
- Yu Ping Tang
- Michigan State University, Department of Psychology, East Lansing, MI 48824, United States; Michigan State University, Neuroscience Program, East Lansing, MI 48824, United States.
| | - Juli Wade
- Michigan State University, Department of Psychology, East Lansing, MI 48824, United States; Michigan State University, Department of Zoology, East Lansing, MI 48824, United States; Michigan State University, Neuroscience Program, East Lansing, MI 48824, United States
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18
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Chao A, Paon A, Remage-Healey L. Dynamic variation in forebrain estradiol levels during song learning. Dev Neurobiol 2014; 75:271-86. [PMID: 25205304 DOI: 10.1002/dneu.22228] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 08/18/2014] [Accepted: 09/02/2014] [Indexed: 12/24/2022]
Abstract
Estrogens shape brain circuits during development, and the capacity to synthesize estrogens locally has consequences for both sexual differentiation and the acute modulation of circuits during early learning. A recently optimized method to detect and quantify fluctuations in brain estrogens in vivo provides a direct means to explore how brain estrogen production contributes to both differentiation and neuromodulation during development. Here, we use this method to test the hypothesis that neuroestrogens are sexually differentiated as well as dynamically responsive to song tutoring (via passive video/audio playback) during the period of song learning in juvenile zebra finches. Our results show that baseline neuroestradiol levels in the caudal forebrain do not differ between males and females during an early critical masculinization window. Instead, we observe a prominent difference between males and females in baseline neuroestradiol that emerges during the subadult stage as animals approach sexual maturity. Second, we observe that fluctuating neuroestradiol levels during periods of passive song tutoring exhibit a markedly different profile in juveniles as compared to adults. Specifically, neuroestrogens in the caudal forebrain are elevated following (rather than during) tutor song exposure in both juvenile males and females, suggesting an important role for the early consolidation of tutor song memories. These results further reveal a circadian influence on the fluctuations in local neuroestrogens during sensory/cognitive tasks. Taken together, these findings uncover several unexpected features of brain estrogen synthesis in juvenile animals that may have implications for secondary masculinization as well as the consolidation of recent sensory experiences.
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Affiliation(s)
- Andrew Chao
- Neuroscience and Behavior Program, Center for Neuroendocrine Studies, Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, Massachusetts, 01003
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19
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Chen Q, Zhang X, Zhao Y, Zhou X, Sun L, Zeng S, Zuo M, Zhang X. Sexual differences in cell proliferation in the ventricular zone, cell migration and differentiation in the HVC of juvenile Bengalese finch. PLoS One 2014; 9:e97403. [PMID: 24841082 PMCID: PMC4026142 DOI: 10.1371/journal.pone.0097403] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 04/17/2014] [Indexed: 11/18/2022] Open
Abstract
Song control nuclei have distinct sexual differences and thus are an ideal model to address how brain areas are sexually differentiated. Through a combination of histological analysis and electrical lesions, we first identified the ventricle site for HVC progenitor cells. We then found that there were significant sex differences in the cellular proliferation activity in the ventricular zone of the HVC, the number of migrating cells along the radial cells (positive immunoreactions to vimentin) and differentiation towards neurons. Through co-culturing of male and female slices containing the developing HVC in the same well, we found that the male slices could produce diffusible substances to masculinize the female HVC. By adding estrogen, an estrogen antagonist, brain-derived neurotrophic factor (BDNF) or its antibody into the culture medium, separately or in combination, we found that these diffusible substances may include estrogen and BDNF. Finally, we found that 1) estrogen-induced BDNF upregulation could be detected 48 hr after estrogen treatment and could not be blocked by a vascular endothelial growth factor (VEGF) receptor inhibitor and 2) the amount of VEGF mRNA expressed in the developing HVC and its adjacent area did not display any significant sex differences, as did the distribution of VEGF and laminin-expressing endothelial cells in the developing HVC. Because these findings are largely different from previous reports on the adult female HVC, it is suggested that our estrogen-induced BDNF up-regulation and the resultant sexual differentiation might not be mediated by VEGF and endothelial cells, but instead, may result from the direct effects of estrogen on BDNF.
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Affiliation(s)
- Qiong Chen
- Beijing Key Laboratory of Gene Resource and Molecular Development, Beijing Normal University, Beijing, China
- Department of Laboratory Medicine, The Third Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Xuebo Zhang
- Beijing Key Laboratory of Gene Resource and Molecular Development, Beijing Normal University, Beijing, China
- College of Life Sciences, Hainan Normal University, Haikou, China
| | - Yueliu Zhao
- Beijing Key Laboratory of Gene Resource and Molecular Development, Beijing Normal University, Beijing, China
| | - Xin Zhou
- Beijing Key Laboratory of Gene Resource and Molecular Development, Beijing Normal University, Beijing, China
| | - Lina Sun
- Beijing Key Laboratory of Gene Resource and Molecular Development, Beijing Normal University, Beijing, China
| | - Shaoju Zeng
- Beijing Key Laboratory of Gene Resource and Molecular Development, Beijing Normal University, Beijing, China
| | - Mingxue Zuo
- Beijing Key Laboratory of Gene Resource and Molecular Development, Beijing Normal University, Beijing, China
| | - Xinwen Zhang
- College of Life Sciences, Hainan Normal University, Haikou, China
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20
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Maehiro S, Takeuchi A, Yamashita J, Hiraki T, Kawabata Y, Nakasone K, Hosono K, Usami T, Paul-Prasanth B, Nagahama Y, Oka Y, Okubo K. Sexually dimorphic expression of the sex chromosome-linked genes cntfa and pdlim3a in the medaka brain. Biochem Biophys Res Commun 2014; 445:113-9. [DOI: 10.1016/j.bbrc.2014.01.131] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 01/25/2014] [Indexed: 10/25/2022]
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21
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The biological basis of human sexual orientation: is there a role for epigenetics? ADVANCES IN GENETICS 2014; 86:167-84. [PMID: 25172350 DOI: 10.1016/b978-0-12-800222-3.00008-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Sexual orientation is one of the largest sex differences in humans. The vast majority of the population is heterosexual, that is, they are attracted to members of the opposite sex. However, a small but significant proportion of people are bisexual or homosexual and experience attraction to members of the same sex. The origins of the phenomenon have long been the subject of scientific study. In this chapter, we will review the evidence that sexual orientation has biological underpinnings and consider the involvement of epigenetic mechanisms. We will first discuss studies that show that sexual orientation has a genetic component. These studies show that sexual orientation is more concordant in monozygotic twins than in dizygotic ones and that male sexual orientation is linked to several regions of the genome. We will then highlight findings that suggest a link between sexual orientation and epigenetic mechanisms. In particular, we will consider the case of women with congenital adrenal hyperplasia (CAH). These women were exposed to high levels of testosterone in utero and have much higher rates of nonheterosexual orientation compared to non-CAH women. Studies in animal models strongly suggest that the long-term effects of hormonal exposure (such as those experienced by CAH women) are mediated by epigenetic mechanisms. We conclude by describing a hypothetical framework that unifies genetic and epigenetic explanations of sexual orientation and the continued challenges facing sexual orientation research.
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22
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Unterwald EM, Page ME, Brown TB, Miller JS, Ruiz M, Pescatore KA, Xu B, Reichardt LF, Beverley J, Tang B, Steiner H, Thomas EA, Ehrlich ME. Behavioral and transcriptome alterations in male and female mice with postnatal deletion of TrkB in dorsal striatal medium spiny neurons. Mol Neurodegener 2013; 8:47. [PMID: 24369067 PMCID: PMC3880973 DOI: 10.1186/1750-1326-8-47] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 12/19/2013] [Indexed: 01/05/2023] Open
Abstract
Background The high affinity tyrosine kinase receptor, TrkB, is the primary receptor for brain derived neurotrophic factor (BDNF) and plays an important role in development, maintenance and plasticity of the striatal output medium size spiny neuron. The striatal BDNF/TrkB system is thereby implicated in many physiologic and pathophysiologic processes, the latter including mood disorders, addiction, and Huntington’s disease. We crossed a mouse harboring a transgene directing cre-recombinase expression primarily to postnatal, dorsal striatal medium spiny neurons, to a mouse containing a floxed TrkB allele (fB) mouse designed for deletion of TrkB to determine its role in the adult striatum. Results We found that there were sexually dimorphic alterations in behaviors in response to stressful situations and drugs of abuse. Significant sex and/or genotype differences were found in the forced swim test of depression-like behaviors, anxiety-like behaviors on the elevated plus maze, and cocaine conditioned reward. Microarray analysis of dorsal striatum revealed significant dysregulation in individual and groups of genes that may contribute to the observed behavioral responses and in some cases, represent previously unidentified downstream targets of TrkB. Conclusions The data point to a set of behaviors and changes in gene expression following postnatal deletion of TrkB in the dorsal striatum distinct from those in other brain regions.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Michelle E Ehrlich
- Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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23
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Tang YP, Wade J. Developmental changes in BDNF protein in the song control nuclei of zebra finches. Neuroscience 2013; 250:578-87. [PMID: 23920158 DOI: 10.1016/j.neuroscience.2013.07.062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/25/2013] [Accepted: 07/27/2013] [Indexed: 12/31/2022]
Abstract
The zebra finch song system provides an excellent model to study the mechanisms underlying the development of sex difference in brain structure and function. Only male zebra finches sing and the brain nuclei controlling song learning and production are considerably larger than in females. Sexual differentiation may in part be regulated by estrogen, but other molecules including neurotrophic factors likely also affect masculinization. Brain derived neurotrophic factor (BDNF) plays a crucial role in numerous aspects of vertebrate brain development and function, including neurogenesis, cell survival, growth of axonal projections, synaptogenesis and processes linked to learning and memory. The current study investigated the expression of BDNF protein in juvenile males and females at four ages, as well as in adults, to begin to evaluate the potential roles of endogenous BDNF in particular stages of structural and functional development of the song system. In both HVC and the robust nucleus of the arcopallium (RA), males had more BDNF+ cells than females. The number of immunopositive cells increased in males and decreased in females as they matured, in a pattern generally consistent with a role for BDNF in sensorimotor integration of song learning. In addition, in HVC (but not RA) the ratio of mature BDNF compared to its precursor proBDNF was greater in adult males than those at post-hatching day 25, indicating a region-specific shift in the relative availability of the two forms. Collectively, the data suggest that changes in BDNF protein expression across development may be associated with song system maturation, particularly during the sensorimotor integration of masculine vocalizations.
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Affiliation(s)
- Y P Tang
- Michigan State University, Department of Psychology, East Lansing, MI 48824, USA; Michigan State University, Neuroscience Program, East Lansing, MI 48824, USA.
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24
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Wade J, Peabody C, Tang YP, Qi L, Burnett R. Estradiol modulates neurotransmitter concentrations in the developing zebra finch song system. Brain Res 2013; 1517:87-92. [PMID: 23628476 PMCID: PMC3674499 DOI: 10.1016/j.brainres.2013.04.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/10/2013] [Accepted: 04/11/2013] [Indexed: 01/02/2023]
Abstract
The neural song system in zebra finches is highly sexually dimorphic; only males sing and the brain regions controlling song are far larger in males than females. Estradiol (E2) administered during development can partially masculinize both structure and function. However, additional mechanisms, including those through which E2 may act, remain unclear. Male and female zebra finches were treated with E2 or control vehicle from post-hatching days 3 through 25, at which time norepinephrine (NE), dopamine (DA) and serotonin (5-HT) were measured in individual nuclei of the song system. Main effects of sex were not detected. However, E2 increased NE in the robust nucleus of the arcopallium (RA). In HVC (proper name), the hormone decreased 5-HT across the two sexes and increased DA in females only. These effects suggest that, while baseline levels of these neurotransmitters may not contribute to sexually dimorphic development of the song system, they could play specific roles in functions common to both sexes and/or in modification of the song system by exogenous E2.
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Affiliation(s)
- Juli Wade
- Department of Psychology, Michigan State University, East Lansing, MI 48824, USA.
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25
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Qi LM, Wade J. Sexually dimorphic and developmentally regulated expression of tubulin-specific chaperone protein A in the LMAN of zebra finches. Neuroscience 2013; 247:182-90. [PMID: 23727504 DOI: 10.1016/j.neuroscience.2013.05.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 05/16/2013] [Accepted: 05/17/2013] [Indexed: 01/06/2023]
Abstract
Sex differences in brain and behavior exist across vertebrates, but the molecular factors regulating their development are largely unknown. Songbirds exhibit substantial sexual dimorphisms. In zebra finches, only males sing, and the brain areas regulating song learning and production are much larger in males. Recent data suggest that sex chromosome genes (males ZZ; females ZW) may play roles in sexual differentiation. The present studies tested the hypothesis that a Z-gene, tubulin-specific chaperone protein A (TBCA), contributes to sexual differentiation of the song system. This taxonomically conserved gene is integral to microtubule synthesis, and within the song system, its mRNA is specifically increased in males compared to females in the lateral magnocellular nucleus of the anterior nidopallium (LMAN), a region critical for song learning and plasticity. Using in situ hybridization, Western blot analysis, and immunohistochemistry, we observed effects of both age and sex on TBCA mRNA and protein expression. The transcript is increased in males compared to females at three juvenile ages, but not in adults. TBCA protein, both the number of immunoreactive cells and relative concentration in LMAN, is diminished in adults compared to juveniles. The latter was also increased in males compared to females at post-hatching day 25. With double-label immunofluorescence and retrograde tract tracing, we also document that the majority of TBCA+ cells in LMAN are neurons, and that they include robust nucleus of the arcopallium-projecting cells. These results indicate that TBCA is both temporally and spatially primed to facilitate the development of a sexually dimorphic neural pathway critical for song.
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Affiliation(s)
- L M Qi
- Neuroscience Program, Michigan State University, East Lansing, MI 48824-1101, USA.
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26
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Tomaszycki ML, Dzubur E. 17β-Hydroxysteroid dehydrogenase type IV, a Z-linked gene, is higher in females than in males in visual and auditory regions of developing zebra finches. Brain Res 2013; 1520:95-106. [PMID: 23692956 DOI: 10.1016/j.brainres.2013.05.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 05/08/2013] [Accepted: 05/10/2013] [Indexed: 11/16/2022]
Abstract
One of the most important decisions in a monogamous animal's life is the choice of a partner (partner preference), but the process by which this occurs remains poorly understood. The present study tests the hypothesis that hormones and genes play a role in sexual differentiation of partner preferences, as in the song system. We focused on a Z-linked gene, 17β-hydroxysteroid dehydrogenase type IV (HSD17B4), coding for a steroidogenic enzyme that converts estradiol (E2) into an inactive metabolite. HSD17B4 mRNA is expressed more in the song regions of males compared to females throughout development, suggesting that regulation of E2 is important for male-typical song development. Here, we focused on four regions associated with sexual partner preferences. Females had significantly higher levels of HSD17B4 mRNA in auditory (caudomedial nidopallium) and visual (hyperpallium apicale) regions than did males at day 25. HSD17B4 was expressed in the hippocampus and caudolateral nidopallium, but there were no sex differences. In a second experiment, animals of both sexes were treated with E2 and HSD17B4 and androgen receptor (AR) mRNA were measured, since masculinization of the song system is, in part, accomplished by AR. AR was low across the four regions and was not sexually differentiated. E2 treatments increased HSD17B4 mRNA in the auditory region of males, which is contrary to findings in the song system. Our research suggests that different behaviors may be guided by the same genes and hormones, but that the exact nature of the gene-hormone relationships may differ according to brain region and behavior.
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