Glanzman D L
Dept of Physiological Science, University of California, Los Angeles 90024 1568.
Trends Neurosci. 1995 Jan;18(1):30-6. doi: 10.1016/0166-2236(95)93947-v.
Classical conditioning of the withdrawal reflex of the marine snail Aplysia californica can be used as an important model system for investigating the neurobiology of associative learning. It results when weak tactile stimulation of the snail's mantle shelf or siphon is repeatedly paired with strong electrical shocks to the animal's tail. This learned behavioral change is thought to be mediated by a presynaptic neuronal mechanism-activity-dependent presynaptic facilitation of the connections between sensory and motor neurons in the CNS of Aplysia. Recent evidence suggests, however, that another type of synaptic plasticity-Hebbian potentiation of the sensorimotor connections-might contribute to classical conditioning in Aplysia. Additional evidence indicates that this relatively simple form of learning is likely to be mediated by multiple neuronal mechanisms.
海兔（加州海兔）缩鳃反射的经典条件作用可作为研究联想学习神经生物学的重要模型系统。当对海兔的外套膜或虹吸管进行弱触觉刺激，并反复与对其尾部的强电击配对时，就会产生这种现象。这种习得的行为变化被认为是由一种突触前神经元机制介导的，即活动依赖的突触前易化作用，它发生在海兔中枢神经系统中感觉神经元和运动神经元之间的连接上。然而，最近的证据表明，另一种类型的突触可塑性——感觉运动连接的赫布式增强——可能也有助于海兔的经典条件作用。更多证据表明，这种相对简单的学习形式可能由多种神经元机制介导。
