Parabigeminal, pretectal and hypothalamic afferents to rat's dorsal lateral geniculate nucleus. Comparison between albino and pigmented strains.

In adult pigmented and albino rats different fluorescent dyes were injected into the dorsal lateral geniculate nuclei of opposite sides. Differences between the strains occur mainly in parabigemino-geniculate and pretecto-geniculate projections. Both the major contralateral and the minor ipsilateral parabigemino-geniculate projections in albinos were clearly smaller then those in pigmented rats. In pigmented rats but not in albinos the parabigemino-geniculate projections originated mainly from the region where the vertical meridian is represented and contained a small number of neurones projecting bilaterally. In each strain, a small number of retrogradely labelled neurones was found in the ipsilateral and contralateral lateral hypothalami.