Some telencephalic connections in the frog, Rana pipiens.

Some afferent, efferent and intrinsic connections of the telencephalon of Rana pipiens were studied using a horseradish peroxidase method. Afferents to the telencephalon from thalamic and brain stem cell groups were demonstrated. These findings, taken together with the results of previous studies, indicate that separate thalamic cell groups project visual, auditory and somatosensory information onto the striatum. A separate thalamic cell group projects to the medial telencephalic wall and probably conveys visual and somatosensory information. These telencephalic afferent systems do not appear to be directly comparable to those of birds and reptiles. Additionally, some telencephalic afferents demonstrated in previous studies using anterograde degeneration techniques were confirmed, and some intratelencephalic connections were identified.