Mineralocorticoid receptor overexpression in basolateral amygdala reduces corticosterone secretion and anxiety.
BACKGROUND
The amygdala plays a critical role in the development of anxiety and the regulation of stress hormone secretion. Reciprocally, stress and stress hormones can induce amygdala hypertrophy, a phenomenon related to enhanced anxiety. As such, modulating amygdaloid function can potentially reduce maladaptive features of the stress response. The amygdala contains two kind of receptor for corticosteroids, the adrenal steroid hormone released during stress: glucocorticoid receptors (GRs) and mineralocorticoid receptors (MRs). Although high-affinity MRs are heavily occupied during basal conditions, low-affinity GRs are heavily occupied only by stress levels of glucocorticoids. Prolonged and heavy occupancy of GRs tends to mediate the deleterious effects of glucocorticoids on neurons, whereas MR occupancy tends to mediate beneficial effects.


METHODS
In this report, we overexpress MR in neurons of adult rat basolateral amygdala, with a herpes simplex viral vector coding for two copies of MR.


RESULTS
Such overexpression reduced anxiety, as measured on an elevated plus-maze, and reduced the magnitude of glucocorticoid secretion after an acute stressor.


CONCLUSIONS
Thus, increasing MR signaling in basolateral amygdala could be valuable in management of stress disorders.
Mitra
Rupshi
R
Department of Biology, Stanford University, Stanford, California 94305, USA. rupshi@stanford.edu
Ferguson
Deveroux
D
Sapolsky
Robert M
RM
D000679:Amygdala / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D001007:Anxiety / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D003345:Corticosterone / Q000097:blood*; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000235:genetics; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics; D008297:Male; D018782:Maze Learning / Q000502:physiology; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018161:Receptors, Mineralocorticoid / Q000235:genetics / Q000378:metabolism*; D018139:Simplexvirus / Q000235:genetics; D018709:Statistics, Nonparametric
D018161:Receptors, Mineralocorticoid; D049452:Green Fluorescent Proteins; D003345:Corticosterone