Study On The Distribution Of Neuropeptide Y In The Medulla Oblongata And Cerebellum Of Aves

Neuropeptide Y (NPY), a 36 amino acid neuropeptide, is widely distributed in the central and peripheral nervous systems. Neuropeptide Y has a lot of physiological effects. It has been reported that neuropeptide Y stimulates food intake, decreases thermogenesis, modulates pituitary hormone secretion and has anxiolytic and anti-convulsant effects in central nervous system. The multiple physiological effects of neuropeptide Y are mediated by at least six different G protein-coupled receptors designated Y1, Y2, Y3 Y4, Y5, and Y6.In order to investigate the localization of neuropeptide Y immunoreactive neurons in medulla oblongata and cerebellum of aves, the medulla oblongata and cerebelli of Taihe silky fowl, pigeon, New jianghan domestic chicken and African ostrich were studied by the immunohistochemical SABC staining method (StreptAvidin-Biotin complex), and compared with broiler and rat. In addition, the cytoarchitecture of the cerebelli and the medulla oblongata of Taihe silky fowl and the medulla oblongata of African ostrich were studied by the HE staining method and compared with Pekin duck using comparative neuroanatomical method.The results are as follows: (1) immunoreactive neurons of NPY in medulla oblongata of Taihe silky fowl, New jianghan domestic chicken are mainly localized in the inferior olivary nucleus. Low levels of that are also observed within the lateral reticular nucleus and raphes nucleus; (2)immunoreactive neurons of NPY in cerebellum of Taihe silky fowl and pigeon are mainly distributed in Purkinje cell layer of cerebellar cortex, especially in the top of Purkinje cell in cerebellar folia; NPY neurons are not found in molecular layer, granular layer of the cerebellar cortex; (3)the gigantocellular reticular nuclei of Taihe silky fowl are well developed; there are three layers in the cerebellar cortex of Taihe silky fowl including molecular layer, Purkinye cell layer and granular layer from outside to inside; there are ten lobules in cerebellum and each lobule includes two or three cerebellar folia except I, II and X lobules; (4) the dorsal motor nucleus of the vagus nerve and nucleus ambiguus in African ostrich are well developed, and the parsrostralis of nucleus of the solitary tract is underdevelopedThe results of the present study indicate that: (l)the localization of neuropeptide Y immunoreactive neurons in the medulla oblongata of Taihe silky fowl and New jianghan domestic chicken are similar to that of rat, but, is different from that of broiler; (2)the localization of neuropeptide Y immunoreactive neurons in the cerebellar cortex of silky fowl and pigeon are similar to that of broiler and rat; (3) ditsribution of the nuclei of silky fowl medulla oblongata is similar to Pekin duck's; Compared with Pekin duck, the gigantocellular reticular nuclei of Taihe silky fowl are well developed; Morphology and cytoarchitecture of Taihe silky fowl cerebellum is similar to other domestic fowls; (4)the inferior olivary nucleus of New Jianghan chicken is also well developed; (5distribution of the nuclei of ostrich medulla oblongata is similar, to Pekin duck's; neurons of the nuclei in African ostrich medulla oblongata are generally larger than that of Pekin duck.