[Incorporation of 3H-phenylalanine into the proteins of cerebral neurons and glia during elaboration of a defensive conditioned reflex].

The passive avoidance conditioning enhanced incorporation of 3H-phenylalanine into the total proteins of neurons and glial cells of CA3 hippocampus area and motor cortex, layer V. During the strengthening and maintenance of the reflex (6, 9, and 24 hrs after the learning session), turnover of proteins in the neurons and glial cells of CA3 hippocampus returned (rapidly in neurons, slowly in glia) to the level of active control. In the motor cortex, this decrease did not stop at the evel of active control: protein tureover decreased even below this level in all the cells after 9 hrs while in neuronal nuclei as late as after 24 hours.