title: Duration of retrograde amnesia induced by tetrodotoxin inactivation of the parabrachial nuclei is inversely related to the intensity of footshock in rat's passive avoidance response.
abstract: Previous work has demonstrated that in rats post-trial bilateral functional blockade of the parabrachial nuclei by local injection of tetrodotoxin (10 ng in 1 microliter) partially disrupts retention of an overtrained passive avoidance response. The time-course of functional blockade disrupting effects on passive avoidance response has been studied by altering both the acquisition-tetrodotoxin injection interval and footshock intensity as independent variables. When week footshocks (0.8 mA) were delivered, functional ablation of the parabrachial nuclei was still effective when induced up to 8 days after acquisition training. On the other hand, when rats were shocked with the stronger stimuli (1.2 mA), 2 days after acquisition functional ablation was no longer effective. The results are discussed in terms of unconditioned stimulus (US) intensity and engram consolidation.
authors.affiliation: Dipartimento di Scienze Fisiologiche, Firenze, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Bucherelli
authors.forename: G
authors.initials: G
authors.lastname: Tassoni
mesh_terms: D000648:Amnesia, Retrograde / Q000139:chemically induced*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D004597:Electroshock; D008297:Male; D011149:Pons / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013779:Tetrodotoxin
chemical_list: D013779:Tetrodotoxin