Gene expression analysis in the parvalbumin‐immunoreactive PV1 nucleus of the mouse lateral hypothalamus

Abstract

A solitary, elongated cluster of parvalbumin-immunoreactive neurons has been previously observed in the rodent ventrolateral hypothalamus. However, the function of this so-called PV1 nucleus is unknown. In this article, we report the results of an unbiased, broad and in-depth molecular characterization of this small, compact group of neurons. The Allen Brain Atlas database of in situ hybridization was screened in order to identify genes expressed in the PV1-nucleus-containing area of the hypothalamus, and those that might be co-expressed with parvalbumin. Although GABA is the principal neurotransmitter in parvalbumin-expressing cells in various other brain areas, we found that PV1 neurons express the vesicular glutamate transporter (VGlut) VGlut2-encoding gene Slc17a6 and are negative for the glutamic acid decarboxylase 1 (GAD1) gene. These cells also express the mRNA for the neuropeptides Adcyap1 and possibly Nxph4, express several types of potassium and sodium channels, are under the control of the neurotransmitter acetylcholine, bear receptors for the glial-derived neurotrophic factor, and produce an extracellular matrix rich in osteopontin. The PV1 nucleus is thus composed of glutamatergic nerve cells, expressing some typical markers of long-axon, projecting neurons (e.g. VGlut2), but also co-expressing genes typical of short-axon GABA neurons (e.g. a variety of potassium channels). Hence, neurons of the PV1 nucleus combine physiological characteristics of interneurons with those of projection neurons.

Expression of the calcium binding proteins Necab-1,-2 and -3 in the adult mouse hippocampus and dentate gyrus

“…The procedure involved using alkaline-phosphatase labeled anti-DIG. Details of the method have been recently published (Girard et al, 2011). Different probes were incubated with adjacent sections, so that the gene of interest was flanked by two identical control probes:…”

Reduction in 50-kHz call-numbers and suppression of tickling-associated positive affective behaviour after lesioning of the lateral hypothalamic parvafox nucleus in rats

“…Experiments in which anterograde tracers, particularly Cre-recombinase-dependent viral ones, have been injected into PV-Cre or Foxb1-Cre mice, have revealed the parvafox nucleus to project mainly to the periaqueductal grey matter (PAG), and, more specifically, to the ventrolateral [8] and the dorsolateral [9] columns. Furthermore, in-situ hybridization has disclosed PV-expressing neurons of the parvafox nucleus to be glutamatergic and thus excitatory [10], in contrast to those in most other brain areas, such as the neocortex, the hippocampus and the cerebellum [11].…”

“…The lateral tuberal nucleus (LTN) of primates shares topographical as well as some neurochemical features in common with the rodent parvafox nucleus [10,14]. Neurons of the LTN manifest pathological alterations in Pick's disease, in which loss of speech is one of the symptoms [15].…”

Discharge properties of neurons recorded in the parvalbumin-positive (PV1) nucleus of the rat lateral hypothalamus

“…According to topographical mapping of the gene expression and double-labeling for glutamate and for PV it is extremely likely that the PV-positive neurons of the PV1-nucleus are glutamatergic projecting neurons [4,8]. Glutamate is an excitatory amino acid assumed to represent the main neurotransmitter used for distribution and transmission of information in the brain [9].…”