| Abstract: | Studied the effects of drug administration to 220 male Sprague-Dawley rats on spontaneous alternation (SA) in a -maze which Ss were permitted to freely explore for 8-min sessions. Results show that SA was not affected by administration of methysergide or the serotonin (5-HT) depletors DL-chloroamphetamine (PCA) and DL-p-chlorophenylalanine (PCPA). However, either LSD, or d-amphetamine in combination with methysergide, PCA, or PCPA interfered with SA. Scopolamine also disrupted SA, but pretreatment with 5-hydroxytryptophan or amphetamine blocked this action. Amphetamine reversal of the scopolamine-induced disruption of SA did not occur in Ss depleted of 5-HT or pretreated with methysergide. Amphetamine disrupted habituation of exploratory activity alone or after PCPA or PCA. PCPA or PCA alone did not affect habituation. Scopolamine interfered with habituation of activity. Methysergide caused an increase in the initial activity level, while LSD produced a dose-dependent decrease. (34 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
