Src is a non-receptor tyrosine kinase that participates in several neuronal processes including synaptic plasticity. We have recently shown that the amounts of total Src and its two phosphorylated forms, at tyrosine-416 (activated) and tyrosine-527 (inhibited), undergo time-dependent, region-specific learning-related changes in the domestic chick forebrain after visual imprinting. These changes occur only in the intermediate medial mesopallium (IMM), a site of learning and memory formation for visual imprinting. Src contains a region of low sequence conservation, which interacts with mitochondrial genome-coded NADH dehydrogenase subunit 2 (NADH2). NADH2 is a component of mitochondrial respiratory complex I but this interaction occurs outside mitochondria, at brain excitatory synapses involving NMDA glutamate receptors. The involvement of Src-NADH2 complexes in learning and memory is not explored yet. In the present study, we inquired if Src-NADH2 complexes are changed 1 h and 24 h after imprinting training in the chick IMM and posterior pole of the nidopallium (PPN) - a control brain region not involved in imprinting. We show for the first time that, independently of changes in total Src or total NADH2, NADH2 bound to Src immunoprecipitated from the P2 plasma membrane-mitochondrial fraction: (i) is increased in a learning-related manner in the left IMM 1 h after the end of training; (ii) 24 h after training, is decreased in the right IMM in a learning-related way. These changes are attributable to learning that occurred during training and not to a predisposition to learn. Learning-related changes in Src-bound NADH2 are therefore time- and region-dependent.