VIP-like and GFAP-like immunoreactivities in the chicken brain stem. I. The medulla

An immunocytochemical analysis was performed on the chicken medulla according to the PAP-DAB procedure, to study the distribution here of the neurons reacting to anti-VIP antibodies and the gliocytes reacting to anti-GFAP antibodies. Positive and negative controls were carried out in both the immunoreactions. The findings seem to indicate that more numerous VIP-immunoreactive neurons are located in the chicken than in the rat or mouse medulla, mainly in its intermediate 1/3, that VIP-immunoreactive fibres connect the medullar group of immunoreactive neurons with at least the first three cervical neuromeres, and confirm also for the chicken medulla, as already reported in other species by various researchers, the close relation of some VIP-immunoreactive neuronal processes with the small blood vessel walls, and the distribution of the GFAP-immunoreactive gliocytes.