Although the expression of several connexins has been reported in the central nervous system, only Cx36 and Cx45 have been undoubtedly demonstrated as part of electrical synapses. Dopamine neurons of the substantia nigra pars compacta (SNc), whose electrical activity is important for goal directed behavior, learning, working memory, reward and modulation of motor activity, communicate with other Dopamine neurons through electrical synapses. However, the expression profile of connexins in the SNc has only been determined in the rat. Considering that electrical synchronization of Dopamine neurons could have important roles in the modulation of levels of Dopamine released both locally and in the areas of innervation, and therefore in the functioning of Dopamine circuits, we decided to determine the expression profile of connexins in freshly isolated cells from SNc of adult mice. Using single cell RT-PCR, we show that a subset of DA neurons, and neurons of glutamate and GABA phenotypes, express Cx45 as well Cx26, Cx30, Cx31.1, Cx32 and Cx43, but not Cx36. Thus our results suggest that in adult mice, Cx45 is the connexin used by some of DA neurons of the SNc to be electrically coupled. Our results also suggest that glutamate and GABA neurons of the SNc, could also be electrically coupled with DA neurons. Despite the inability of the other connexins to form functional gap junctions in neurons, the expression of Cx26, Cx30, Cx32 and Cx43 may be the reflect of the ability of the neurons of SNc to release neuromodulators through hemichannel activity.