کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5924399 1571195 2013 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Enkephalin and dynorphin mRNA expression are associated with resilience or vulnerability to chronic social defeat stress
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی فیزیولوژی
پیش نمایش صفحه اول مقاله
Enkephalin and dynorphin mRNA expression are associated with resilience or vulnerability to chronic social defeat stress
چکیده انگلیسی


- Sprague-Dawley rats were exposed to a resident-intruder model of defeat.
- Resilience and vulnerability were defined by their average latency to be defeated.
- ENK expression in the BLA may promote the resilience to chronic social stress.
- DYN expression in accumbens may promote the vulnerability to chronic social stress.

There are important and enduring differences between individuals in the magnitude of all aspects of the stress response. Among the neuropeptide systems, the endogenous opioids enkephalin (ENK) and dynorphin (DYN), are very interesting candidates to participate in the naturally occurring variations in coping styles and to determine the individual capacity for adaptation during chronic stress exposure. Under chronic social stress exposure, we hypothesize that changes in the ENKergic vs DYNergic neuronal systems within specific nuclei of the basal forebrain contribute to naturally occurring variations in coping styles and will determine individual capacities for stress adaptation. Sprague-Dawley rats were exposed to a resident-intruder model of defeat for 7 days. The average latency to be defeated over seven consecutive days was calculated for each intruder rat. Based on this distribution, we chose an average defeat latency of 350 s as a cutoff criterion to define resilient and vulnerable rats. A subpopulation assumed a subordinate posture in a relatively short latency (< 350 s, SL) and the other subpopulation resisted defeat resulting in longer latencies (> 350 s, LL) to assume this posture and were identified as being vulnerable and resilient respectively. Rats were euthanized 24 h after the last stress session. ENK mRNA expression was lower in the basolateral nucleus of the amygdala in vulnerable compared to control and resilient individuals. In contrast, there was no difference between resilient and control individuals. DYN mRNA is increased only within the dorsal and medial shell of the NAc of vulnerable rats compared to control individuals. There was no difference between resilient and control individuals. DYN mRNA is increased in resilient individuals in the central area of the striatum, caudal part, compared to control individuals. DYN is also increased in medial area of the striatum, caudal part in resilient and vulnerable compared to control individuals. These results have broad implications for understanding the functional roles of opioid neurotransmission following repeated social stress and suggest that ENK could facilitate the adaptation of behavioral responses by opposition to the DYN neurotransmission that appears to promote maladaptive behavioral response to chronic social stress.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physiology & Behavior - Volume 122, 2 October 2013, Pages 237-245
نویسندگان
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