Mpitsos G J, Davis W J
Science. 1973 Apr 20;180(4083):317-20. doi: 10.1126/science.180.4083.317.
Naive specimens of the marine gastropod Pleurobranchaea withdraw from tactile stimulation of the oral veil and show feeding responses to food chemicals. Experimental subjects, trained by pairing touch (conditioned stimullus) with food chemicals (unconditioned stimulus), soon acquired a classically conditioned feeding response to touch alone. Control subjects that received touch alone or unpaired touch and food chemicals showed significantly fewer feeding responses to touch than did experimentals. Classically conditioned specimens were used for avoidance conditioning. Subjects that received aversive electrical stimulation when they did not withdraw from touch rapidly learned to withdraw rather than to feed in response to touch alone. Controls that received touch alone or unpaired touch and shock continued to exhibit the feeding response to touch alone. The learned responses persisted for up to 2 weeks without reinforcement before extinction, and could be demonstrated in the isolated nervous system.
海洋腹足纲动物侧鳃的未受训练的标本会对口膜的触觉刺激产生退缩反应，并对食物化学物质表现出进食反应。通过将触摸（条件刺激）与食物化学物质（非条件刺激）配对进行训练的实验对象，很快就获得了仅对触摸产生的经典条件反射进食反应。单独接受触摸或接受未配对的触摸和食物化学物质的对照对象，与实验对象相比，对触摸的进食反应明显更少。经典条件反射的标本用于回避条件反射。当未迅速从触摸中退缩时接受厌恶电刺激的对象很快学会了退缩，而不是仅对触摸做出进食反应。单独接受触摸或接受未配对的触摸和电击的对照对象继续表现出仅对触摸的进食反应。习得的反应在消退前无需强化可持续长达2周，并且可以在离体神经系统中得到证明。
