Ontogeny of the behavioral effects of lysergic acid diethylamide in cats

Summary

Kittens aged 21 days began to show behaviors induced by LSD, such as limb-flicking and grooming, which were not observed in younger kittens. These behaviors increased with age, reaching adult levels by about 35-40 days. The effects of LSD lasted approximately 8 hours after injection, similar to adult cats, and young kittens did not develop tolerance to LSD with repeated doses. This suggests that the necessary neural and muscular systems for these behaviors are present before they naturally occur.

Study at a glance

Abstract

AbstractThe ontogeny of the behavioral effects of lysergic acid diethylamide (LSD) was examined in cats between the ages of 4 and 112 days postpartum. The kittens showed little LSD‐induced behavioral change prior to 14 days of age. By the age of 21 days, however, the kittens exhibited many of the behavioral signs characteristic of LSD‐induced behaviors in adult cats. These behaviors include limbflicking, abortive grooming, head‐shakes, grooming, and investigatory responses. In general, these behaviors began at a low frequency of occurrence, then increased rapidly with advancing age, reaching adult values by approximately 35–40 days of age, and remained relatively constant through 112 days postpartum. The time course for the behavioral effects following an acute injection of LSD showed the adult pattern, i.e., persisting for approximately 8 hr post‐injection, from their earliest appearance during ontogeny. Young kittens (21–42 days of age) were resistant to the development of tolerance following repeated administration of the drug. LSD was capable of eliciting certain behaviors, such as head‐shakes and grooming, well in advance of the age at which they normally appear spontaneously. This indicates that the neuronal and musculature substrata are developed for the performance of these behaviors long before the kitten naturally employs them.