XXXX receptors: immunocytochemical localization in the dorsal cochlear nucleus.

@entity1 @entity671 @entity2608 @entity9423 @entity840 @entity9197 @entity35 @entity468
In the cochlear nucleus of mammals, the relatively homogeneous responses of auditory nerve fibers are transformed into a variety of different response patterns by the different classes of resident neurons. The spectrum of these responses is hypothesized to depend on the types and distribution of receptors, ion channels, G proteins, and second messengers that form the signaling capabilities in each cell class. In the present study, we examined the immunocytochemical distribution of the @entity671 ( @entity9197 in the dorsal cochlear nucleus to better understand how this second messenger might be involved in shaping the neural signals evoked by sound. Affinity-purified polyclonal antibodies directed against the @entity9423 labeled a homogeneous population of neurons in the dorsal cochlear nucleus of @entity35 , @entity840 , mustache bats, @entity468 , New World owl monkeys, @entity2608 , and @entity1 . These cells were all darkly immunostained except in the @entity1 where the labeling was less intense. Immunoblots of dorsal cochlear nucleus tissue from the @entity35 revealed a single band of protein of molecular weight approximately 260 kD, which is the same size as the purified receptor, indicating that our antibodies reacted specifically with the @entity9423 . These immunolabeled neurons were identified as cartwheel cells on the basis of shared characteristics across species, including cell body size and distribution, the presence of a highly invaginated nucleus, and a well-developed system of cisternae. Reaction product was localized along the membranes of rough and smooth endoplasmic reticulum, subsurface cisternae, and the nuclear envelope. This label was distributed throughout the cartwheel cell body and dendritic shafts but not within dendritic spines, axons, or axons terminals. The regular pattern of immunolabeling across mammals suggests that IP3 and cartwheel cells are conserved in evolution and that both play an important but as yet unknown role in hearing.
