CYTOSOLIC HIPPOCAMPAL PKC AND AGING - CORRELATION WITH DISCRIMINATIONPERFORMANCE

ADULT and aged mice were submitted to a discrimination task in a radia l maze (regular trials), and then to probe trials requiring them to fo rm relational representations. Three weeks later, animals were again t ested for regular and probe trials. Following another interval of 3 we eks, individual hippocampal cytosolic calcium-dependent and -independe nt PKC activities were measured. Performance of aged animals was impai red on probe but not regular trials and aged mice had lower hippocampa l cytosolic calcium-dependent and -independent PKC activities than adu lts. Performance on probe trials was specifically correlated with calc ium-dependent PKC activity. This suggests a specific relationship betw een the ability to form relational representations and hippocampal cyt osolic calcium-dependent PKC activity.