Peer-reviewed
Suprachiasmatic nucleus projection to the medial prefrontal cortex: a viral transneuronal tracing study
The viral transneuronal labeling method was used to examine whether the suprachiasmatic nucleus (SCN) is linked by multisynaptic connections to the medial prefrontal cortex of the rat. In separate experiments, pseudorabies virus (PRV) was injected into one of the three different cytoarchitectonic regions that comprise the medial prefrontal cortex: infralimbic (Brodmann area 25), prelimbic (Brodmann area 32), and cingulate (Brodmann area 24) cortical areas. After 4-days survival, extensive SCN transneuronal labeling was found following infralimbic cortex (ILC) injections, but almost none occurred when the PRV injections were centered in the prelimbic or cingulate areas. In the ILC cases, transneuronal labeling was localized mainly in the dorsomedial SCN, although a moderate number of labeled neurons were found in the ventrolateral SCN. About 13% of the infected neurons were vasopressin immunoreactive and 4% were vasoactive intestinal polypeptide-positive. Another set of experiments was performed in which the paraventricular thalamic nucleus (PVT) was destroyed 2 weeks prior to making PRV injections into the ILC. Almost no SCN transneuronal labeling occurred in these animals, suggesting that the SCN projection to the ILC is dependent on a relay in the PVT
Article