title: 5-HT1A receptor blockade targeting the basolateral amygdala improved stress-induced impairment of memory consolidation and retrieval in rats.
abstract: The aim of the present study was to investigate the possible role of basolateral amygdala (BLA) 5-HT1A receptors in memory formation under stress. We also examined whether the blockade of these receptors is involved in stress-induced state-dependent memory. Adult male Wistar rats received cannula implants that bilaterally targeted the BLA. Long-term memory was examined using the step-through type of passive avoidance task. Behavioral stress was evoked by exposure to an elevated platform (EP) for 10, 20 and 30min. Post-training exposure to acute stress (30min) impaired the memory consolidation. In addition, pre-test exposure to acute stress-(20 and 30min) induced the impairment of memory retrieval. Interestingly, the memory impairment induced by post-training exposure to stress was restored in the animals that received 20- or 30-min pre-test stress exposure, suggesting stress-induced state-dependent memory retrieval. Post-training BLA-targeted injection of a selective 5-HT1A receptor antagonist, (S)-WAY-100135 (2μg/rat), prevented the impairing effect of stress on memory consolidation. Pre-test injection of the same doses of (S)-WAY-100135 that was targeted to the BLA also reversed stress-induced memory retrieval impairment. It should be considered that post-training or pre-test BLA-targeted injection of (S)-WAY-100135 (0.5-2μg/rat) by itself had no effect on the memory formation. Moreover, pre-test injection of (S)-WAY-100135 (2μg/rat) that targeted the BLA inhibited the stress-induced state-dependent memory retrieval. Taken together, our findings suggest that post-training or pre-test exposure to acute stress induced the impairment of memory consolidation, retrieval and state-dependent learning. The BLA 5-HT1A receptors have a critical role in learning and memory under stress.
authors.affiliation: Department of Animal Biology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Sardari
authors.affiliation: Department of Animal Biology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran. Electronic address: rezayof@khayam.ut.ac.ir.
authors.forename: A
authors.initials: A
authors.lastname: Rezayof
authors.affiliation: Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran.
authors.forename: M-R
authors.initials: MR
authors.lastname: Zarrindast
mesh_terms: D000208:Acute Disease; D000818:Animals; D066272:Basolateral Nuclear Complex / Q000187:drug effects* / Q000503:physiopathology; D002408:Catheters, Indwelling; D004195:Disease Models, Animal; D008297:Male; D000069077:Memory Consolidation / Q000187:drug effects / Q000502:physiology; D008569:Memory Disorders / Q000188:drug therapy* / Q000503:physiopathology; D057567:Memory, Long-Term / Q000187:drug effects / Q000502:physiology; D011939:Mental Recall / Q000187:drug effects / Q000502:physiology; D018697:Nootropic Agents / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology*; D017208:Rats, Wistar; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism; D058829:Serotonin 5-HT1 Receptor Antagonists / Q000494:pharmacology*; D013315:Stress, Psychological / Q000188:drug therapy* / Q000503:physiopathology
chemical_list: D018697:Nootropic Agents; D010879:Piperazines; D058829:Serotonin 5-HT1 Receptor Antagonists; D044282:Receptor, Serotonin, 5-HT1A; C081293:WAY 100135
keywords: (S)-WAY-100135; acute elevated platform stress; basolateral amygdala; memory formation; rat(s)