Learning and Memory: Genetics

development of brain structures and function. We studied the participation of proteins having neurotrophic and neurogrowth activities, like S 100beta and A3G7, in the adult rat model of short-and long-term habituation of acoustic startle reaction (ASR) with freezing behaviour recorded simultaneously. It was observed that rabbit polyclonal antibodies against protein S100beta, and monoclonal antibodies against protein A3G7, influenced in a selective and a dose-dependent way both storage and retrieval of ASR. Application of antibodies against S100beta and A3G7 in various brain structures (cerebellar cortex, hippocampus) caused different types of behavioural effects. Subsequently, the increase of S100beta ratio in several brain structures and 48 hours) following elaboration of long-term habituation of ASR in adult rats. We found that S 100beta content in each structure showed specific temporal and quantitative variations. The present data provide experimental evidence of the heterochronia of molecular mechanisms associated with learning and memory in the adult brain.