Scopolamine's effect on passive avoidance behavior in immature rats

Abstract

Male albion rats ranging in age from 15-30 days were injected with either scopolamine hydorbromide or saline, prior to training and retention testing on a black-white passive avoidance (PA) task. Pretraining administration of a 1.0-mg/kg dose of scopolamine significantly increased the median number of trails to criterion for 18-, 21-, and 30-day-old rat pups when compared with their saline controls. Fifteen-day-olds showed drug-related PA deficits when a 2.0-mg/kg dose was given. Retention data reflect characteristic age-dependent memory loss over the 1-week acquistionretention period with no apparent state-dependent effects. The data suggest the presence of cholinergic inhibitory mediation of PA responding in preweanling and postweanling pups.

Enhancement of passive avoidance learning through small doses of intra‐amygdaloid physostigmine in the young rat. Its relation to the development of acetylcholinesterase

“…The same disruptive effect is also observed in young mice (Ray & Nagy, 1978) and rats (Blozovski, Cudennec, & Garrigou, 1977;Blozovski & Hennocq, 1982;Feigley, 1974;Wilson & Riccio, 1976) …”

“…On the other hand, acquisition of PA responses is delayed after intraperitoneal administration of cholinergic receptor blocking agents (see Carlton & Markiewicz, 1971). The same disruptive effect is also observed in young mice (Ray & Nagy, 1978) and rats (Blozovski, Cudennec, & Garrigou, 1977;Blozovski & Hennocq, 1982;Feigley, 1974;Wilson & Riccio, 1976) from postnatal Days One of the cholinergic pathways specifically involved in PA learning in the adult rat is located in the amygdala (Todd & Kesner, 1978), especially in its basal lateral part, and evidence has been obtained that the functional maturation of this cholinergic system parallels the ontogenetic development of the animal's acquisition capabilities. Based on the effects of injections into the lateral, the basolateral, or the cortical nucleus of antimuscarinic (Blozovski & DumCry, 1984;Dumery & Blozovski, 1987) and antinicotinic agents (Blozovski & DumCry, 1987), the conclusion was drawn that muscarinic transmission becomes effective on PND 13 and the nicotinic one, on PND 11.…”

Early Isolation Produces Enduring Hyperactivity in the RAT, But no Effect upon Spontaneous Alternation

“…Thus they do not offer support for the suggestion that slow habituation, hyperactivity, and poor alternation reflect the malfunctioning of a single inhibitory system (Carlton, 1969;Wilson and Riccio, 1976;Feigley, Parsons, Hamilton and Spear, 1972). The development of these behaviours in the young rat also argues against a unitary control system; habituation to a simple stimulus is present at 2 days of age (File and Scott, 1976), although habituation to a more complex stimulus may not develop until about 18 days of age (Feigley et at., 1972).…”

Handbook of Psychopharmacology

“…Impaired learning has subsequently been shown in studies using pretreatment with cholinergic antagonists in both rats (Berger andStein. 1969: Blozovski andHennocq, 1982;Feigley, 1974;Mollenauer et al, 1976;Wilson and Riccio, 1976) and mice (Calhoun and Smith, 1968;Calhoun I'f at., 1970;Bohdaneckv and Jarvik, 1967;Dilts and Berry, 1967;Glick and Zimmerberg, 1971). Intraventricular injections of pyrrolcholine, a choline analog that competes for uptake and is converted to acetylpyrrolcholine (an inactive form of the transmitter), also impair initial learning (Glick et al .. 197:)).…”