The ontogeny of phencyclidine‐induced wall climbing and locomotor activity

Abstract

Wall climbing behavior is an age-specific behavior that is elicited during postnatal Days 7 through 17 by various stimuli that include heat, odors, shock, and the catecholaminergic agonists apomorphine, amphetamine, and clonidine. In a previous study, a significant amount of wall climbing behavior was observed during ataxia and activity testing following phencyclidine (PCP) administration in Day 19 but not Day 40 rat pups. The present study describes the ontogeny of PCP-induced wall climbing behavior and locomotor activity. Frequency and duration of wall climbing bouts and locomotor activity were recorded on Days 5, 12, 19, 26, 33, or 40 following PCP treatment. On Day 12, all doses of PCP induced significant amounts of wall climbing behavior. A similar pattern of results was observed on Day 5 although these effects were not statistically significant. After Day 12, PCP-induced wall climbing behavior declined precipitously. PCP increased locomotor activity at all ages tested with maximum activities observed on Day 19. These results demonstrate that PCP-elicited wall climbing behavior follows an ontogenetic profile similar to that previously reported for other stimuli and that there are robust ontogenetic differences in the locomotor response to PCP.

Adolescent but Not Adult Rats Exhibit Ethanol‐Mediated Appetitive Second‐Order Conditioning

“…Furthermore, adolescents exhibited a significant positive correlation between preference for CS 2 (sandpaper) and wall‐climbing scores, particularly in the experimental condition (LP Group) that yielded ethanol‐mediated place preference. Wall‐climbing seems to decline as a function of age (Scalzo and Burge, 1992). This raises the possibility that adults failed to exhibit ethanol‐related changes in wall‐climbing just because the latter is not a pertinent dependent variable for mature subjects.…”