Efferent connections of the parvalbumin‐positive (PV1) nucleus in the lateral hypothalamus of rodents

Abstract

A solitary cluster of parvalbumin-positive neurons-the PV1-nucleus-has been observed in the lateral hypothalamus of rodents. In the present study, we mapped the efferent connections of the rodent PV1-nucleus using non-specific antero-and retrograde tracers in rats, and chemoselective, Cre-dependent viral constructs in parvalbumin-Cre mice. In both species, the PV1-nucleus was found to project mainly to the periaqueductal grey matter (PAG), preponderantly ipsilateral. Indirectly in rats and directly in mice, a discrete, longitudinallyorientated cylindrical column of terminal fields (PV1-CTF) was identified ventrolateral to the aqueduct on the edge of the PAG. The PV1-CTF, which is particularly dense in the rostral portion, located in the supraoculomotor nucleus (Su3), is spatially interrupted over a short stretch at the level of the trochlear nucleus and abuts caudally on a second parvalbum in-positive (PV2) nucleus. The rostral and the caudal portions of the PV1-CTF consist of axonal endings that stem from scattered neurons throughout the PV1-nucleus. Minor terminal fields were identified in a crescentic column of the lateral PAG, as well as in the Edinger-Westphal-, the lateral habenularand the laterodorsal tegmental nuclei. So far no obvious functions can be attributed to this small, circumscribed column ventrolateral to the aqueduct, the prime target of the PV1-nucleus.

GABAA and GABAB receptor subunit localization on neurochemically identified neurons of the human subthalamic nucleus

“…Parvalbumin (PV): A mouse monoclonal antibody raised against PV (Swant, Bellinzona, Switzerland, cat# 235, RRID: AB_10000343) was used that specifically detects the 45 Ca‐binding spot of PV shown in 2D immunoblots (manufacturer's product sheet) and recognizes one band of 12 kDa in western blots of brain homogenates from various species (Celio et al, ). A lack of immunoreactivity was found in the cerebral cortex of a knockout mouse (Schwaller et al, ).…”