Distribution on four types of cytokines in the brain of the toad, Bufo gargariizans

Cytokines play an important role in the brain. A large number of experiments have showed that cytokines were expressed in the central nervous system of animals. In this paper, the strept avidin-biotin-peroxidase complex (SABC) immunohistochemical methods were applied to investigate the distribution of IL-1, IFN-, NGF- and TNF- in the brain of adult toads, Bufo gargariizans. It found that quantities of IL-1-like immunoreactive cells were detected and widely distributed in each region of the brain. IL-1 was mainly located in the bodies of positive cells. However, in the primordial hippoeampus, nucleus anterodorsalis tegmenti and nucleus anterovetralis tegmenti, positive cells bodies and progresses were all labeled by IL-1. Also, a large number of cells were stained by IFN-, these positive cells were observed in the primordial hippoeampus and septum of telencephalon, ventrolateral thalamus nucleus of thalamus, preoptic area, suprachiasmatic nucleus and ventral infundibular nucleus of hypothalamus, nucleus anterodorsalis tegmenti, nucleus anterovetralis tegmenti, posterodorsal tegmental nucleus and posteroventral tegmental nucleus of mesencephalon, Purkinje cell layer of cerebellum, and reticular nuclei of medulla oblongata. Only in the primordial hippoeampus, nucleus anterodorsalis tegmenti, posterodorsal tegmental nucleus, Purkinje cell layer and reticular nuclei, progresses of these positive cells were IFN--like immunoreactive. A few NGF--like immunoreactive cells were mainly observed in the preoptic area and suprachiasmatic nucleus of hypothalamus, nucleus anterovetralis tegmenti of mesencephalic tegmentum, Purkinje cell layer of cerebellum, and reticular nuclei of medulla oblongata. NGF--like immunoreactivity was also presented in the progresses of these positive cells in the preoptic area, Purkinje cell layer and reticular nuclei. Several cells in the nucleus anterodorsalis tegmenti of mesencephalic tegmentum, and reticular nuclei and raphe nuclei of medulla oblongata, were labeled by TNF-. And, their bodies and progresses were all TNF--like immunoreactive. Therefore, these results indicated that IL-1 and IFN- were widely expressed and may play an important and extensive role in the brain, but NGF- and TNF- were only presented in some specific regions and may take effect in these regions in the brain.