Archer T., Beninger R.J., Järbe T.U.C., Seiden L.S.
Department of Psychology, University of Gothenburg, Box 14158, S-400 20 Göteborg, Sweden.
Behav Pharmacol. 1989;1(3):191-199.
Animals neonatally depleted of dopamine show decreases in exploratory behaviour. As latent learning may depend on exploratory behaviour the present study was undertaken to examine the effects of neonatal dopamine depletion on latent learning. In two experiments dopamine was depleted neonatally, using 6-hydroxydopamine injected intracisternally on day 1 after birth. In both experiments, exploratory behaviour, measured as rearing and head-dip responses in a modified openfield/holeboard, was reduced in the dopamine depleted rats whereas ambulatory behaviour was elevated. In a modified radial arm maze also, rearing responses were decreased while ambulation was increased for the 6-hydroxydopamine treated rats. Latent learning was tested in each experiment following preexposure to the maze for either a single trial or four trials. 6-Hydroxydopamine treated rats demonstrated a comparable latent learning effect to vehicle treated rats after four maze exposures but showed a greatly attenuated latent learning effect following only a single exposure. It is suggested that the effects of neonatal dopamine upon maze and latent learning are secondary to the effects on hyperactivity, reduced exploration and/or increased neophobia shown by these rats.
新生期多巴胺缺失的动物探索行为会减少。由于潜在学习可能依赖于探索行为，因此开展了本研究以检验新生期多巴胺缺失对潜在学习的影响。在两个实验中，于出生后第1天经脑池内注射6-羟基多巴胺，使多巴胺在新生期缺失。在两个实验中，多巴胺缺失的大鼠在改良旷场/洞板试验中以竖尾和探头反应衡量的探索行为均减少，而自主活动行为增加。在改良放射状臂迷宫试验中，6-羟基多巴胺处理的大鼠竖尾反应减少，而移动增加。在每个实验中，在对迷宫进行单次或四次预暴露后测试潜在学习。6-羟基多巴胺处理的大鼠在四次迷宫暴露后表现出与溶剂处理的大鼠相当的潜在学习效应，但仅单次暴露后潜在学习效应则大幅减弱。提示新生期多巴胺对迷宫和潜在学习的影响继发于这些大鼠所表现出的多动、探索减少和/或新异恐惧增加。
