Article ID Journal Published Year Pages File Type
6265438 Brain Research 2010 13 Pages PDF
Abstract

We performed this study to understand the anatomical substrates of parabrachial nucleus (PBN) modulation of orexin (ORX)-containing neurons in the hypothalamus. After biotinylated dextranamine (BDA) injection into the lateral PBN and immunostaining of ORX-containing neurons in the rat, the prominent overlap of the distribution field of the BDA-labeled fibers and that of the ORX-immunoreactive (ir) neurons was found in the lateralmost part of the dorsomedial nucleus and adjacent dorsal perifornical area (this overlapping field was referred to as “suprafornical area” in the present study), and the labeled axon terminals made asymmetrical synaptic contacts with somata and dendrites of the ORX-ir neurons. We further revealed that almost all the “suprafornical area”-projecting lateral PBN neurons were positive for vesicular glutamate transporter 2 mRNA and very few of them were positive for glutamic acid decarboxylase 67 mRNA. The present data suggest that ORX-containing neurons in the “suprafornical area” may be under the excitatory influence of the glutamatergic lateral PBN neurons probably for the regulation of arousal and waking.

Research Highlights►Lateral parabrachial fibers are distributed in the orexin field of the hypothalamus. ►Lateral parabrachial axons make asymmetrical synapses with orexin neurons. ►Lateral parabrachial neurons projecting to the orexin field are glutamatergic.

Related Topics
Life Sciences Neuroscience Neuroscience (General)
Authors
, , , , ,