Abstract
Stress is a precipitating factor in depression and anxiety disorders. Patients with these disorders often show amygdala abnormalities. The basolateral amygdala (BLA) is integral in mood and emotion, and is sensitive to stress. While much is known about effects of stress on BLA neuron activity and morphology in males, less is known in females. We tested whether repeated stress exerts distinct effects on BLA in vivo neuronal activity and morphology of Golgi-stained BLA neurons [lateral (LAT) and basal (BA) nuclei] in adult female rats. Repeated restraint stress increased BLA neuronal firing and caused hypertrophy of BLA neurons in males, while it decreased LAT and BA neuronal firing and caused hypotrophy of neurons in the LAT of females. BLA neuronal activity and function, such as fear conditioning, shifts across the estrous cycle. Repeated stress disrupted this pattern of BLA activity and fear expression over the estrous cycle. The disruptive effects of stress on the pattern of BLA function across estrous may produce behavior that is non-optimal for a specific phase of the estrous cycle. The contrasting effects of stress may contribute to sex differences in the effects of stress on mood and psychiatric disorders.
Highlights
Psychiatric disorders such as generalized anxiety disorder, major depressive disorder, and post-traumatic stress disorder (PTSD) afflict a huge number of people, the majority of which are female[1,2,3,4,5,6]
Recent evidence demonstrates that basolateral amygdala (BLA) physiology and function shifts across the estrous cycle in rats such that lateral nucleus (LAT) activity and LAT-dependent cued conditioned fear is greatest during diestrus while basal nucleus (BA) activity and BA-dependent contextual fear is greatest during proestrus[43]
Repeated restraint stress increased adrenal gland weight in male and female rats (main effect of stress, F(1,140) = 5.948, p = 0.0160, two-way Analysis of Variance (ANOVA); p < 0.05 Holm-Sidak’s multiple comparisons test, n = 65 control female, n = 31 stress female, n = 26 control male, n = 22 stress male), indicating that this was an effective stressor in both sexes
Summary
Psychiatric disorders such as generalized anxiety disorder, major depressive disorder, and post-traumatic stress disorder (PTSD) afflict a huge number of people, the majority of which are female[1,2,3,4,5,6]. The BLA is comprised of several nuclei, including the lateral nucleus (LAT) and the basal nucleus (BA) These nuclei contribute to overlapping but different aspects of BLA-dependent behaviors, display differences in neuronal activity between males and females[43] and may be differentially sensitive to stress[23,35,36,37]. Both of these nuclei will be separately examined in this study. The second goal of this study was to determine if repeated stress disrupts the pattern of BLA changes that usually occurs across the estrous cycle
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
