The distribution of acetylcholinesterase in brainstem auditory nuclei of canaries

Previous research on brainstem auditory nuclei of avians has focused on cytoarchitecture, connectivity and synaptology. As an initial investigation of the neurochemistry of these structures, we examined the distribution of acetylcholinesterase (AChE) in n. angularis, n. magnocellularis and n. laminaris in canaries. Histochemical analyses revealed intense staining of neuronal somata in n. angularis and n. magnocellularis and light-to-moderate staining of neuronal somata in n. laminaris. Neuropil of n. angularis and n. laminaris stained positively, and the former was more intense than the latter. These findings suggest that neurons in n. angularis and n. magnocellularis are very rich in AChE, whereas neurons in n. laminaris are not.