Acute and chronic single dose effects of LSD-25 on visual discrimination in rats

Rats subjected to either a frontal cortex lesion or to a sham operation were trained to discriminate between a lighted and unlit alley to escape shock. Following intubation with either placebo or LSD-25 (1.0 mg/kg), they were given discrimination trials 2 hr, 1 week, and 1 month later, but with an increased level of task difficulty. Single dose effects of LSD-25 were observed acutely in a transient impairment of visual discrimination accuracy, and more chronically in slower running time. Although no significant drug-lesion interactions were noted, the results were in the direction of a combinatory effect. The value of increasing the level of post-treatment task was confirmed.