Gene expression analysis of the critical period in the visual cortex.

The development of the primary visual cortex in animals possessing binocular vision is a classical paradigm for the study of activity-dependent neuronal plasticity. To elucidate the genetic determinants of this period of substantial plasticity, we conducted an unbiased and comprehensive transcript profiling analysis with differential display and DNA array techniques. We characterized the transcripts that change significantly between the critical and postcritical periods in the rat binocular visual cortex. We determined if these changes are specific for the visual cortex by simultaneously profiling the hippocampus and examined the impact of sensory experience on the accumulation of the identified transcripts. Our results uncover visual cortex-specific and unspecific transcription programs. Transcripts for protein kinases and phosphatases are particularly regulated. The identified transcripts support the notion that the critical period provides a permissive state for plasticity.