Distribution of CRF- and tyrosine hydroxylase-immunoreactive neurons in the brainstem of the domestic fowl ( Gallus domesticus)

Abstract

The distribution of CRF and tyrosine hydroxylase (TH)-immunoreactive neurons was examined in the brainstem of the chicken. Very dense populations of both CRF and TH-immunoreactive (-ir) perikarya are co-extensive in separate neuronal systems throughout a large field of the rostral brainstem, encompassing locus ceruleus, the mesencephalic reticular formation, parabrachial nucleus, and the dorsal and ventral tegmental areas. They are present also in nucleus tractus solitarius, and sparsely in the ventral and lateral areas of the medulla. This co-distribution suggests that the effects of CRF upon central autonomic activity may be mediated via brainstem catecholamine systems. CRF-ir neurons alone are present also in midline nuclei, including n. centralis superior, n.annularis, n.linearis caudalis, and the raphae.