Hall_1994_Neurosci.Lett_182_222

We examined the distribution of acetycholinesterase (AChE) in the brainstem auditory nuclei of leopard frogs (Rana pipiens). Numerous AChE-labeled somata were observed in caudal brainstem nuclei including the dorsolateral nucleus, superior olivary nucleus, and superficial reticular nucleus. At midbrain levels, AChE-labeled somata were observed in the magnocellular, principal and laminar nuclei of the torus semicircularis, though, most were located in the magnocellular nucleus. Neuropil labeling, while present throughout the auditory brainstem, was particularly pronounced in the principal nucleus of the torus. These findings suggest that the auditory system of anurans, like that of birds and mammals, comprises, in part, distinct cholinergic pathways.