Effects of androgens on volumes of sexually dimorphic brain regions in the zebra finch

1980 ◽  
Vol 185 (2) ◽  
pp. 441-444 ◽  
Author(s):  
Arthur P. Arnold
Keyword(s):  
Zebra Finch ◽  
Brain Regions ◽  
Sexually Dimorphic

scholarly journals Aromatase is pre-synaptic and sexually dimorphic in the adult zebra finch brain

2005 ◽  
Vol 272 (1576) ◽  
pp. 2089-2096 ◽  
Author(s):  
R. Scott Peterson ◽  
Lakshmi Yarram ◽  
Barney A Schlinger ◽  
Colin J Saldanha
Keyword(s):  
Zebra Finch ◽  
Brain Regions ◽  
Projection Neurons ◽  
Aromatase Activity ◽  
Sexually Dimorphic ◽  
Brain Areas ◽  
Synaptic Boutons ◽  
Caudomedial Nidopallium ◽  
Vertebrate Central Nervous System

Oestrogens organize and activate circuits within the vertebrate central nervous system. Oestrogen synthesis occurs via the expression of aromatase, a P 450 enzyme detected in microsomes and more recently in pre-synaptic boutons. Synaptic aromatase has only been described in brain regions that express aromatase in many subcellular compartments, so its function remains poorly understood. To more thoroughly study the role of oestrogen synthesis at synaptic terminals, we examined the ultrastructural compartmentalization of aromatase in the zebra finch; a species in which high aromatase activity can be measured in brain areas that do not contain somal aromatase. Here, we report the presence of aromatase in pre-synaptic boutons in the hippocampus and the high vocal centre brain areas with low and undetectable somal aromatase, respectively, in addition to areas with abundant somal aromatase such as the preoptic area and caudomedial nidopallium. At these brain areas, males had more total synapses, more aromatase pre-synaptic boutons and importantly, the proportion of total synaptic profiles that expressed aromatase was significantly higher in males relative to females. Aromatase-positive pre-synaptic boutons were always observed innervating aromatase-negative post-synaptic elements. We conclude that oestrogen may be provided to discrete oestrogen-sensitive targets by synaptic aromatization. Further, some targets may be exposed to more oestrogen in males. The expression of aromatase in individual synapses of projection neurons represents a unique mechanism of neuroendocrine action. Neurons with steroidogenic capability may modulate distant targets with the specificity of axonal innervation.

The melanocortin-3 receptor is a pharmacological target for the regulation of anorexia

2021 ◽  
Vol 13 (590) ◽  
pp. eabd6434
Author(s):  
Patrick Sweeney ◽  
Michelle N. Bedenbaugh ◽  
Jose Maldonado ◽  
Pauline Pan ◽  
Katelyn Fowler ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Feeding Behavior ◽  
Critical Role ◽  
Brain Regions ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Female Mice ◽  
Bidirectional Regulation ◽  
Fear And Anxiety ◽  
Agouti Related Protein

Ablation of hypothalamic AgRP (Agouti-related protein) neurons is known to lead to fatal anorexia, whereas their activation stimulates voracious feeding and suppresses other motivational states including fear and anxiety. Despite the critical role of AgRP neurons in bidirectionally controlling feeding, there are currently no therapeutics available specifically targeting this circuitry. The melanocortin-3 receptor (MC3R) is expressed in multiple brain regions and exhibits sexual dimorphism of expression in some of those regions in both mice and humans. MC3R deletion produced multiple forms of sexually dimorphic anorexia that resembled aspects of human anorexia nervosa. However, there was no sexual dimorphism in the expression of MC3R in AgRP neurons, 97% of which expressed MC3R. Chemogenetic manipulation of arcuate MC3R neurons and pharmacologic manipulation of MC3R each exerted potent bidirectional regulation over feeding behavior in male and female mice, whereas global ablation of MC3R-expressing cells produced fatal anorexia. Pharmacological effects of MC3R compounds on feeding were dependent on intact AgRP circuitry in the mice. Thus, the dominant effect of MC3R appears to be the regulation of the AgRP circuitry in both male and female mice, with sexually dimorphic sites playing specialized and subordinate roles in feeding behavior. Therefore, MC3R is a potential therapeutic target for disorders characterized by anorexia, as well as a potential target for weight loss therapeutics.

Oxytocin and Vasopressin: Mechanisms for Potential Sex Differences Observed in Autism Spectrum Disorders

2013 ◽  
Author(s):  
C. Sue Carter ◽  
Suma Jacob
Keyword(s):  
Autism Spectrum Disorders ◽  
Arginine Vasopressin ◽  
Protective Factor ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Sexually Dimorphic ◽  
Unique Role ◽  
Spectrum Disorders ◽  
Brain And Behavior ◽  
And Behavior

The effects of oxytocin and vasopressin on the brain and behavior can be sexually dimorphic, especially during the course of development (Bales, Kim, et al., 2004; Bales, Pfeifer, et al., 2004; Bales, Plotsky, et al., 2007; Bielsky et al., 2005a; Carter, 2003; Thompson et al., 2006; Yamamoto et al., 2005; Yamamoto et al., 2004). Given the sexual discrepancy observed in autism spectrum disorders (ASDs), these two neuropeptides, oxytocin (OT) and arginine vasopressin (AVP), have received attention for their potential role in ASDs (Green and Hollander, 2010; Insel et al., 1999; Leckman & Herman, 2002; Welch et al., 2005; Winslow, 2005; Young et al., 2002). Changes in either OT or AVP and their receptors could be capable of influencing symptom domains or behaviors associated with ASDs. Arginine vasopressin is androgen dependent in some brain regions (De Vries & Panzica, 2006), and males are more sensitive to AVP, especially during development. We hypothesize here that AVP, which has a unique role in males, must be present in optimal levels to be protective against ASDs. Either excess AVP or disruptions in the AVP system could play a role in development of the traits found in ASDs. In contrast, OT may possibly be secreted in response to adversity, especially in females, serving as a protective factor.

Neuronal growth, atrophy and death in a sexually dimorphic song nucleus in the zebra finch brain

Nature ◽  
1985 ◽  
Vol 315 (6015) ◽  
pp. 145-147 ◽  
Author(s):  
Masakazu Konishi ◽  
Eugene Akutagawa
Keyword(s):  
Zebra Finch ◽  
Sexually Dimorphic ◽  
Neuronal Growth

scholarly journals Pubertal hormones modulate the addition of new cells to sexually dimorphic brain regions

2008 ◽  
Vol 11 (9) ◽  
pp. 995-997 ◽  
Author(s):  
Eman I Ahmed ◽  
Julia L Zehr ◽  
Kalynn M Schulz ◽  
Betty H Lorenz ◽  
Lydia L DonCarlos ◽  
...  
Keyword(s):  
Brain Regions ◽  
Sexually Dimorphic

scholarly journals Gene expression correlates of social evolution in coral reef butterflyfishes

2020 ◽  
Vol 287 (1929) ◽  
pp. 20200239 ◽  
Author(s):  
Jessica P. Nowicki ◽  
Morgan S. Pratchett ◽  
Stefan P. W. Walker ◽  
Darren J. Coker ◽  
Lauren A. O'Connell
Keyword(s):  
Gene Expression ◽  
Coral Reef ◽  
Social Evolution ◽  
Brain Regions ◽  
Sexually Dimorphic ◽  
Ventral Telencephalon ◽  
Solitary Living ◽  
Social Variation ◽  
Evolution Of Sociality ◽  
Solitary Species

Animals display remarkable variation in social behaviour. However, outside of rodents, little is known about the neural mechanisms of social variation, and whether they are shared across species and sexes, limiting our understanding of how sociality evolves. Using coral reef butterflyfishes, we examined gene expression correlates of social variation (i.e. pair bonding versus solitary living) within and between species and sexes. In several brain regions, we quantified gene expression of receptors important for social variation in mammals: oxytocin ( OTR ), arginine vasopressin ( V1aR ), dopamine ( D1R, D2R ) and mu-opioid ( MOR ). We found that social variation across individuals of the oval butterflyfish, Chaetodon lunulatus, is linked to differences in OTR , V1aR, D1R, D2R and MOR gene expression within several forebrain regions in a sexually dimorphic manner. However, this contrasted with social variation among six species representing a single evolutionary transition from pair-bonded to solitary living. Here, OTR expression within the supracommissural part of the ventral telencephalon was higher in pair-bonded than solitary species, specifically in males. These results contribute to the emerging idea that nonapeptide, dopamine and opioid signalling is a central theme to the evolution of sociality across individuals, although the precise mechanism may be flexible across sexes and species.

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