scholarly journals Dehydroepiandrosterone Metabolism by 3β-Hydroxysteroid Dehydrogenase/Δ5-Δ4 Isomerase in Adult Zebra Finch Brain: Sex Difference and Rapid Effect of Stress

Endocrinology ◽  
2004 ◽  
Vol 145 (4) ◽  
pp. 1668-1677 ◽  
Author(s):  
Kiran K. Soma ◽  
Noel A. Alday ◽  
Michaela Hau ◽  
Barney A. Schlinger

Abstract Dehydroepiandrosterone (DHEA) is a precursor to sex steroids such as androstenedione (AE), testosterone (T), and estrogens. DHEA has potent effects on brain and behavior, although the mechanisms remain unclear. One possible mechanism of action is that DHEA is converted within the brain to sex steroids. 3β-Hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (3β-HSD) catalyzes the conversion of DHEA to AE. AE can then be converted to T and estrogen within the brain. We test the hypothesis that 3β-HSD is expressed in the adult brain in a region- and sex-specific manner using the zebra finch (Taeniopygia guttata), a songbird with robust sex differences in song behavior and telencephalic song nuclei. In zebra finch brain, DHEA is converted by 3β-HSD to AE and subsequently to estrogens and 5α- and 5β-reduced androgens. 3β-HSD activity is highest in the diencephalon and telencephalon. In animals killed within 2–3 min of disturbance, baseline 3β-HSD activity in portions of the telencephalon is higher in females than males. Acute restraint stress (10 min) decreases 3β-HSD activity in females but not in males, and in stressed animals, telencephalic 3β-HSD activity is greater in males than in females. Thus, the baseline sex difference is rapidly reversed by stress. To our knowledge, this is the first demonstration of 1) brain region differences in DHEA metabolism by 3β-HSD, 2) rapid modulation of 3β-HSD activity, and 3) sex differences in brain 3β-HSD and regulation by stress. Songbirds are good animal models for studying the regulation and functions of DHEA and neurosteroids in the nervous system.

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Joseph M. Baker ◽  
Ning Liu ◽  
Xu Cui ◽  
Pascal Vrticka ◽  
Manish Saggar ◽  
...  

Abstract Researchers from multiple fields have sought to understand how sex moderates human social behavior. While over 50 years of research has revealed differences in cooperation behavior of males and females, the underlying neural correlates of these sex differences have not been explained. A missing and fundamental element of this puzzle is an understanding of how the sex composition of an interacting dyad influences the brain and behavior during cooperation. Using fNIRS-based hyperscanning in 111 same- and mixed-sex dyads, we identified significant behavioral and neural sex-related differences in association with a computer-based cooperation task. Dyads containing at least one male demonstrated significantly higher behavioral performance than female/female dyads. Individual males and females showed significant activation in the right frontopolar and right inferior prefrontal cortices, although this activation was greater in females compared to males. Female/female dyad’s exhibited significant inter-brain coherence within the right temporal cortex, while significant coherence in male/male dyads occurred in the right inferior prefrontal cortex. Significant coherence was not observed in mixed-sex dyads. Finally, for same-sex dyads only, task-related inter-brain coherence was positively correlated with cooperation task performance. Our results highlight multiple important and previously undetected influences of sex on concurrent neural and behavioral signatures of cooperation.


Endocrinology ◽  
2005 ◽  
Vol 146 (4) ◽  
pp. 1650-1673 ◽  
Author(s):  
Jill B. Becker ◽  
Arthur P. Arnold ◽  
Karen J. Berkley ◽  
Jeffrey D. Blaustein ◽  
Lisa A. Eckel ◽  
...  

Abstract Female and male brains differ. Differences begin early during development due to a combination of genetic and hormonal events and continue throughout the lifespan of an individual. Although researchers from a myriad of disciplines are beginning to appreciate the importance of considering sex differences in the design and interpretation of their studies, this is an area that is full of potential pitfalls. A female’s reproductive status and ovarian cycle have to be taken into account when studying sex differences in health and disease susceptibility, in the pharmacological effects of drugs, and in the study of brain and behavior. To investigate sex differences in brain and behavior there is a logical series of questions that should be answered in a comprehensive investigation of any trait. First, it is important to determine that there is a sex difference in the trait in intact males and females, taking into consideration the reproductive cycle of the female. Then, one must consider whether the sex difference is attributable to the actions of gonadal steroids at the time of testing and/or is sexually differentiated permanently by the action of gonadal steroids during development. To answer these questions requires knowledge of how to assess and/or manipulate the hormonal condition of the subjects in the experiment appropriately. This article describes methods and procedures to assist scientists new to the field in designing and conducting experiments to investigate sex differences in research involving both laboratory animals and humans.


2016 ◽  
Vol 28 (4pt2) ◽  
pp. 1229-1243 ◽  
Author(s):  
Tiffany S. Doherty ◽  
Tania L. Roth

AbstractThe efforts of many neuroscientists are directed toward understanding the appreciable plasticity of the brain and behavior. In recent years, epigenetics has become a core of this focus as a prime mechanistic candidate for behavioral modifications. Animal models have been instrumental in advancing our understanding of environmentally driven changes to the epigenome in the developing and adult brain. This review focuses mainly on such discoveries driven by adverse environments along with their associated behavioral outcomes. While much of the evidence discussed focuses on epigenetics within the central nervous system, several peripheral studies in humans who have experienced significant adversity are also highlighted. As we continue to unravel the link between epigenetics and phenotype, discerning the complexity and specificity of epigenetic changes induced by environments is an important step toward understanding optimal development and how to prevent or ameliorate behavioral deficits bred by disruptive environments.


1985 ◽  
Vol 30 (12) ◽  
pp. 999-999
Author(s):  
Gerald S. Wasserman

Author(s):  
Elizabeth Hampson

Organizational and activational effects of sex steroids were first discovered in laboratory animals, but these concepts extend to hormonal actions in the human central nervous system. This chapter begins with a brief overview of how sex steroids act in the brain and how the organizational-activational hypothesis originated in the field of endocrinology. It then reviews common methods used to study these effects in humans. Interestingly, certain cognitive functions appear to be subject to modification by sex steroids, and these endocrine influences may help explain the sex differences often seen in these functions. The chapter considers spatial cognition as a representative example because the spatial family of functions has received the most study by researchers interested in the biological roots of sex differences in cognition. The chapter reviews evidence that supports an influence of both androgens and estrogens on spatial functions, and concludes with a glimpse of where the field is headed.


2009 ◽  
Vol 212 (15) ◽  
pp. 2411-2418 ◽  
Author(s):  
K. W. Sockman ◽  
K. G. Salvante ◽  
D. M. Racke ◽  
C. R. Campbell ◽  
B. A. Whitman

2009 ◽  
Vol 106 (17) ◽  
pp. 7203-7208 ◽  
Author(s):  
Pei-Yu Wang ◽  
Anna Protheroe ◽  
Andrew N. Clarkson ◽  
Floriane Imhoff ◽  
Kyoko Koishi ◽  
...  

Many behavioral traits and most brain disorders are common to males and females but are more evident in one sex than the other. The control of these subtle sex-linked biases is largely unstudied and has been presumed to mirror that of the highly dimorphic reproductive nuclei. Sexual dimorphism in the reproductive tract is a product of Müllerian inhibiting substance (MIS), as well as the sex steroids. Males with a genetic deficiency in MIS signaling are sexually males, leading to the presumption that MIS is not a neural regulator. We challenge this presumption by reporting that most immature neurons in mice express the MIS-specific receptor (MISRII) and that male Mis−/− and Misrii−/− mice exhibit subtle feminization of their spinal motor neurons and of their exploratory behavior. Consequently, MIS may be a broad regulator of the subtle sex-linked biases in the nervous system.


2018 ◽  
Vol 133 ◽  
pp. 189-201 ◽  
Author(s):  
Laura Sánchez-Marín ◽  
David Ladrón de Guevara-Miranda ◽  
M. Carmen Mañas-Padilla ◽  
Francisco Alén ◽  
Román D. Moreno-Fernández ◽  
...  

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