Involvement of stress-released corticotropin-releasing hormone in the basolateral amygdala in regulating memory consolidation.
It is well established that adrenal stress hormone-induced activation of the basolateral complex of the amygdala (BLA) influences memory consolidation. The present experiments investigated the involvement of corticotropin-releasing hormone (CRH) in the BLA in modulating memory consolidation. Bilateral infusions of the CRH receptor antagonist [9-41]-alpha-helical CRH (0.3, 1.0, or 3.0 microg in 0.2 microl) administered into the BLA of male Sprague-Dawley rats immediately after aversively motivated inhibitory avoidance training produced dose-dependent impairment of 48-h retention performance. Because the CRH receptor antagonist infusions did not impair retention when administered into the BLA 3 h after training, the retention impairment selectively was due to time-dependent influences on memory consolidation. Furthermore, because immediate posttraining infusions of [9-41]-alpha-helical CRH into the adjacent central nucleus of the amygdala (CEA) were ineffective, the effect selectively involved the BLA. Immunocytochemistry showed that the aversive training stimulus of a single, brief footshock increased CRH levels in the CEA. These findings indicate that activation of CRH receptors in the BLA, likely by training-induced release of endogenous peptide originating from the CEA, participates in mediating stress effects on memory consolidation.
D000679:Amygdala / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D006727:Hormone Antagonists / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018019:Receptors, Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors; D013312:Stress, Physiological / Q000503:physiopathology* / Q000523:psychology*
D006727:Hormone Antagonists; D010446:Peptide Fragments; D018019:Receptors, Corticotropin-Releasing Hormone; D003346:Corticotropin-Releasing Hormone; C045089:corticotropin releasing hormone (9-41)