Somatic labeling of the medial terminal nucleus of the accessory optic system with WGA-HRP injected into the rat occipital cortex

Neuronal cell bodies in the medial terminal nucleus of the accessory optic system (MTN) were labeled with WGA-HRP which was injected ipsilaterally into the occipital cortex in the rat. We suggest that the label was first transported anterogradely to the pretectal nucleus of the optic tract, then moved transneuronally from axon terminals of occipital cortical neurons to axon terminals of MTN neurons, and finally transported retrogradely to reach cell bodies of MTN neurons.

Topographic organization and collateralization of claustrocortical projections in the rat

The organization of the claustrocortical projections was examined in the rat using a fluorescent retrograde labeling technique. From injections of three different fluorescent tracers into the occipital, frontal and cingulate cortices, claustocortical projections were revealed to be topographically organized in both the rostrocaudal and dorsoventral direction. The dorsoventral topography is similar to that of the primates, but is different from that of the cat. On the basis of a quantitative analysis of the double and triple labeling of single claustral neurons, significant collateralization of the claustrocortical projections is referred.