EN
The sensory system linking mystacial vibrissae to barrels in somatosensory cortex is an object of many studies concerning brain plasticity. Sensory denervation, sensory deprivation and learning paradigms have been used to explore mechanisms of use-dependent plastic changes of cortical physiology, anatomy, neurochemistry and microstructure. The lecture will describe experiments examining changes in functioning of the barrel cortex evoked by classical conditioning in which stimulation of vibrissae was used as CS and tail shock as UCS. Plastic modification of the barrel cortex activation pattern following fear learning was revealed by 2-deoxyglucose autoradiography, showing expanded cortical representation of vibrissae to which CS was applied. This effect was NMDA receptor‑dependent, and modified inhibitory and xcitatory neurotransmission within the barrels. Changes in electrophysiological properties of neurons were observed, together with rapid inhibitory synaptogenesis. Activity dependent alterations were found in the ultrastructure of both inhibitory and excitatory synapses. The role of GABAergic transmission in learning-dependent plasticity of the barrel cortex will be discussed