Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of the present study was to evaluate for the first time the stress-induced hypothalamus-pituitary-adrenal (HPA), adrenocorticotropic hormone (ACTH), corticosterone and prolactin responses of the National Institutes of Health genetically heterogeneous rat stock (N/Nih-HS rats) in comparison with responses of the relatively high and low stress-prone Roman Low- (RLA-I) and High-Avoidance (RHA-I) rat strains. The same rats were also compared (experiment 1) with respect to their levels of unconditioned anxiety (elevated zero-maze test), novelty-induced exploratory behavior, conditioned fear and two-way active avoidance acquisition. In experiment 2, naive rats from these three strains/stocks were evaluated for "depressive-like" behavior in the forced swimming test. N/Nih-HS and RLA-I rats showed significantly higher post-stress ACTH, corticosterone and prolactin levels than RHA-I rats. N/Nih-HS rats also presented the highest context-conditioned freezing responses, extremely poor two-way avoidance acquisition and very low novelty-induced exploratory behavior. Experiment 2 showed that, compared to RHA-I rats, N/Nih-HS and RLA-I rats displayed significantly less struggling (escape-directed) and increased immobility responses in the forced swimming test. Factor analysis of data from experiment 1 showed associations among behavioral and hormonal responses, with a first factor comprising high loadings of elevated zero-maze variables and lower loadings of conditioned fear, two-way avoidance acquisition and hormonal measures, while a second factor mainly grouped conditioned fear and two-way avoidance acquisition with novelty-induced exploration and post-stress prolactin. Thus, regarding their anxiety/fearfulness, passive coping style, "depressive-like" and stress-induced hormonal responses the N/Nih-HS rats resemble the phenotype profiles of the relatively high-anxious and stress-prone RLA-I rat strain.
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PMID:Coping style and stress hormone responses in genetically heterogeneous rats: comparison with the Roman rat strains. 2217 13

The cholinergic and dopaminergic innervation of the amygdala plays an important role in attention, emotional arousal, aversive forms of associative learning, conditioned responses, and stress responsivity. Roman High- (RHA) and Low-Avoidance (RLA) rats are an ideal model to study the potential impact of this innervation on behavioral responses, because they were selected bidirectionally for differences in their two-way active avoidance performance. RHA rats are known to quickly acquire two-way active avoidance and show indications of enhanced impulsive behavior, novelty seeking, and vulnerability to substance abuse, whereas RLA rats exhibit a passive coping style with high levels of immobility and enhanced stress responsivity. In the present study, the density of acetylcholine esterase (AchE)-positive cholinergic fibers and tyrosine hydroxylase immunoreactive (TH-ir) fibers were analyzed in various amygdala nuclei. In comparison to RLA rats, RHA rats displayed a significantly higher density of AchE-positive fibers in the lateral nucleus (La), the major sensory input area of the amygdala. In contrast, RLA rats showed a higher density of TH-ir fibers in the lateral division of the central nucleus (CeL), which modulates amygdala output and is known to contain more corticotropin-releasing hormone (CRH) positive neurons in RLA than in RHA rats. The findings suggest that a higher density of AchE-positive fibers in the La of RHA rats may facilitate attentional mechanisms and aversive forms of associative learning in RHA rats, whereas the increased density of TH-ir fibers in the CeL of RLA rats may be involved in the regulation of enhanced CRH expression and stress responsivity.
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PMID:Density of acetylcholine esterase (AchE) and tyrosine hydroxylase (TH) containing fibers in the amygdala of roman high- and low-avoidance rats. 2758 49