Despite very extensive investigations on molecular processes underlying memory formation, there are very few studies examining potential differences in the brain biochemistry between "good" and "poor" learners belonging to a random population of young animals. In the present study, an attempt was made to correlate individual variation in spatial learning in young-adult Long-Evans rats with hippocampal levels of protein kinase A (PKA), calcium/calmodulin-dependent protein kinase II alpha (CaMKII alpha), and choline acetyltransferase (ChAT). Additionally, in order to indirectly estimate the activity of CaMKII alpha and PKA, hippocampal levels of their phosphorylated forms (pCaMKII alpha and pPKA) were assessed using Western blot technique. Rats were classified as "good" and "poor" learners on the basis of their performance in a partially baited 12-arm radial maze. The biochemical assays did not reveal a significant difference in the basal hippocampal levels of the CaMKII alpha, however, the level of pCaMKII alpha, was significantly higher in "good" learners. Also, hippocampal levels of both PKA and pPKA, as well as that of ChAT, were significantly higher in "good" as compared to "poor" learners. Our results suggest that the differences in the expression level of PICA and ChAT (but not of CaMKII alpha), as well as the differences in the activation of both PICA and CaMKII alpha may contribute to the individual variation in learning skills and episodic-like memory in a random population of young-adult subjects. (C) 2013 Elsevier Ireland Ltd. All rights reserved.