Hypothalamic and basal forebrain afferents to he cat's visual cortex: a study with horseradish peroxidase.

Following injections of horseradish peroxidase into the visual cortex labeled neurons have been found in the nucleus of the diagonal band of Broca in the basal forebrain and in the lateral hypothalamus just rostral to the mammillary bodies. The projection is bilateral, with a strong prevalence of ipsilateral connections. Both the basal forebrain and the lateral hypothalamus project to each of the areas 17, 18 and 19; none of these projections, however, is retinotopically organized. This suggests that the basal forebrain and the lateral hypothalamus are sources of non-specific input to the visual cortex in the cat.