SYNAPTOPHYSIN IMMUNOREACTIVITY IN THE COCHLEAR NUCLEI OF MAMMALS - A COMPARATIVE-STUDY

Synaptophysin is a Ca2+-binding glycoprotein located in the presynapti c membrane and synaptic vesicles. This glycoprotein has been also invo lved in the release of neurotransmitters. The presence of synaptophysi n within the cochlear nuclear complex of several animal species was an alyzed. Differences in size and neuronal density of the cochlear nucle i were observed between the animal species studied. In fact, cat and r at cochlear nuclei showed a very similar morphology and neuronal distr ibution, while mouse, hamster and guinea pig exhibited important diffe rences. The morphology and arrangement of synaptic boutons, for each n euronal type considered, were similar among species.