Low doses of atropine sulfate impair retention of a well-learned spatial task

Abstract

Retention of a well-learned spatial task was assessed in rats 10 minutes prior to, and 10, 20, 30, 40, and 50 minutes after treatment with 3, 10 or 30 mg/kg, iv, atropine sulfate or the equivalent volume of saline, iv. There was a variable dose effect for escape latency and choice accuracy measures of spatial retention. A relatively large dose of atropine sulfate (30 mg/kg, iv) significantly impaired choice accuracy and escape latency compared with the control group. Moreover, impairment in choice accuracy was observed with smaller doses of atropine sulfate (3, 10 mg/kg, iv) than have previously been shown to disrupt spatial retention.

Atropine sulfate impairs selective parameters of performance in the Morris water maze

“…Atropinized animals frequently used a spiral search strategy to locate the platform and always headed in the correct location from the start point. Although our data support previous findings (Hagen et al, 1986;Rauch et al, 1988Rauch et al, , 1989 showing that cholinergic blockade with atropine sulfate disrupts spatial performance when administered prior to retention testing, this type of performance is extremly insensitive when compared to acquisition. Atropine sulfate slowed the performance of rats but not in a dose-dependent manner.…”

“…However, studies of central cholinergic blockade on the retention of overtrained spatial tasks produce conflicting results (Buresova et al, 1986;Costall et al, 1988;Harley, 1979;Whishaw, 1985;Levy et al, 1983;Buresova and Bures, 1982;Eckerman et al, 1980;Hagan et al, 1986;Rauch et al, 1988Rauch et al, , 1989. There may, therefore, be differential cholinergic involvement in task retention as opposed to acquisition.…”

“…Recently, several studies (Hagan et al, 1986;Rauch et al, 1988Rauch et al, , 1989 have shown atropine sulfate impairs the retention of a previously acquired spatial task. Atropine sulfate (30 mg/kg) administered intravenously (iv) significantly impaired escape latency and choice accuracy measures of spatial retention in a modified multiple cross maze (Rauch et al, 1989).…”

“…Recently, several studies (Hagan et al, 1986;Rauch et al, 1988Rauch et al, , 1989 have shown atropine sulfate impairs the retention of a previously acquired spatial task. Atropine sulfate (30 mg/kg) administered intravenously (iv) significantly impaired escape latency and choice accuracy measures of spatial retention in a modified multiple cross maze (Rauch et al, 1989). In addition, when ip, subcutaneous (sc) or iv injections of equal doses of atropine sulfate (30mg/kg) were compared on a spatial retention task in a multiple cross maze, iv and ip atropine sulfate produced significant impairments in choice accuracy (Rauch et al, 1988).…”