Effects of extended training on rats depleted of central and/or peripheral catecholamines.

Thirty-two Wistar rats were used to investigate the effects of extended training on avoidance performance of rats depleted of Catecholamines. They were injected with 6-hydroxydopamine either (i) intracisternally, (ii) intraperitoneally, or (iii) both IP and IC, and trained on the two-way shuttlebox avoidance task. The results on peripheral noradrenaline depletion led to the conclusion that extended training ameliorates the observed behavioural deficit significantly back to the level of controls. The conclusion that is indicated by the present central catecholamine depletion are: (i) central catecholamine depletion has long term effect on behavioural deficit, (ii) central depletion is more detrimental to avoidance learning than peripheral depletion, and (iii) plasma corticosterone plays no significant mediating roles.