PSD95 protein level rises in murine somatosensory cortex after sensory training

Proteins of the postsynaptic density are implicated in mechanisms of synapt ic plasticity. We examined involvement of PSD95 and alpha CaMkII in learnin g-dependent plastic changes of representational maps in somatosensory corte x of mice. The barrel cortex of mice was examined following a 3 day long cl assical conditioning training, in which activation of facial vibrissae was linked to an aversive stimulus. This procedure produced expansion of cortic al representations of vibrissae involved in the training. In subcellular fr action enriched in postsynaptic densities from the barrel cortex, it was es timated by Western blotting that the level of PSD95 increased after the tra ining by about 50%, while the level of CaMkII remained unchanged. The resul ts indicate involvement of PSD95 in learning-dependent cortical plasticity. NeuroReport 12:2907-2910 (C) 2001 Lippincott Williams & Wilkins.