Choline acetyltransferase activity of the principal vestibular nuclei of rat, studied by micropunch technique.

We have assayed choline acetyltransferase (CAT) activity, as a specific marker for cholinergic neurons, in the vestibular nuclear complex (VNC) as a whole, and in the 4 individual principal vestibular nuclei, dissected by a micropunch technique. The VNC contains a significant amount of CAT activity, comparable to that of hippocampus and frontal cortex. CAT activity is relatively concentrated in the medial vestibular nucleus (MVN), which agrees with studies by others showing a greater concentration of muscarinic receptors in MVN. We conclude that cholinergic systems may play a role in central vestibular function, particularly within the MVN.