The ability to respond to environmental stimuli and to adapt to change is fundamental to all aspects of higher cognitive function. Processes as diverse as learning and memory, the development of alternative neuronal pathways during recovery from trauma, the acquisition of pharmacological tolerance and the recognition of olfactory cues in maternal/newborn bonding all depend upon such neuronal plasticity. This course will consider a variety of short-term and long-term plastic phenomena in the nervous system, focusing on the underlying cellular and molecular mechanisms. Specific topics may include plasticity of synaptic function (e.g., LTP in the hippocampus and its possible relevance to memory, cellular correlates of habituation and sensitization in Aplysia), plasticity during development (neurite outgrowth, plasticity of neuronal phenotype, the acquisition of excitability) and plasticity under various pathological conditions (kindling and epilepsy, drug addiction, response to injury). The class will emphasize reading and criticism of articles in the primary literature. Discussions: three hours a week. Evaluation will be based on class participation and several short papers. Prerequisites: Biology 202 and Biology 205 or Biology 212. Enrollment limited to 24. Open to juniors and seniors, with preference to seniors who have not taken a 400-level course.