Afferent and efferent connections of the central prosencephalic nucleus in the Pacific hagfish.

Injections of horseradish peroxidase, or the carbocyanine dye Dil, into the central prosencephalic nucleus of hagfishes reveal reciprocal connections with the septum, preoptic area, habenula, thalamus and hypothalamus. Efferent projections also occur to the olfactory bulb, pallium, posterior tubercle and tegmentum and to the contralateral central prosencephalic nucleus. These connections suggest that the central prosencephalic nucleus of hagfishes may be homologous to portions of the medial pallium and ventral thalamus of other craniates.