Parvalbumin-Neurons of the Ventrolateral Hypothalamic Parvafox Nucleus Receive a Glycinergic Input: A Gene-Microarray Study

Abstract

The ventrolateral hypothalamic parvafox (formerly called PV1-Foxb1) nucleus is an anatomical entity of recent discovery and unknown function. With a view to gaining an insight into its putative functional role(s), we conducted a gene-microarray analysis and, armed with the forthcoming data, controlled the results with the Allen databases and the murine BrainStars (B*) database. The parvafox nucleus was specifically sampled by laser-capture microdissection and the transcriptome was subjected to a microarray analysis on Affymetrix chips. Eighty-two relevant genes were found to be potentially more expressed in this brain region than in either the cerebral cortex or the hippocampus. When the expression patterns of these genes were counterchecked in the Allen-Database of in-situ hybridizations and in the B*-microarray database, their localization in the parvafox region was confirmed for thirteen. For nine novel genes, which are particularly interesting because of their possible involvement in neuromodulation, the expression was verified by quantitative real time-PCR. Of particular functional importance may be the occurrence of glycine receptors, the presence of which indicates that the activity of the parvafox nucleus is under ascending inhibitory control.

Parvalbumin‐expressing ependymal cells in rostral lateral ventricle wall adhesions contribute to aging‐related ventricle stenosis in mice

“…The monoclonal anti‐GFP antibody was raised against GFP protein isolated from the jellyfish A. victoria . We tested the immunofluorescence specificity by confirming that the staining pattern coincided with the eGFP‐expression in Foxj1‐eGFP, respectively in PV‐KO‐eGFP organotypic hippocampal slice cultures (Szabolcsi & Celio, ) and in coronal brain sections derived from Glycine transporter 2 (GlyT2)‐eGFP mice (Szabolcsi, Albisetti, & Celio, ). In Western blot, the antibody detected a single band at about 30 kDa in PV‐eGFP muscle protein extract corresponding to the expected molecular weight, while no signal was detected in the WT brain protein extract (Figure k).…”

Eliminating the VGlut2-Dependent Glutamatergic Transmission of Parvalbumin-Expressing Neurons Leads to Deficits in Locomotion and Vocalization, Decreased Pain Sensitivity, and Increased Dominance

“…Since our study was originally driven by our interest in exploring the functions of the hypothalamic parvafox nucleus, these behavioral tests were mainly selected based on the connections of the parvafox nucleus with the periaqueductal gray matter (PAG). These connections preferentially indicate a possible involvement of the parvafox nucleus in analgesia, vocalization, and defense circuits (Celio et al, 2013 ; Bilella et al, 2016 ; Szabolcsi et al, 2017 ). In addition, a study that evaluated the effects of interfering with the fast synaptic inhibition onto PV-expressing neurons (Leppä et al, 2011 ) has also contributed to our selection of behavioral tests.…”

The PV2 cluster of parvalbumin neurons in the murine periaqueductal gray: connections and gene expression

“…Some of the genes (e.g., Spp1 , Efr3a , Kcna1 ) showed a very faint but almost exclusive expression in the PV2 cluster in and around the PAG, whereas others (e.g., Adcyap1r1 , Gad1 , Gad2 ) were expressed more strongly but throughout the entire lateral and/or ventrolateral PAG and LDTg. Comparisons were made to previous studies of the parvafox nucleus (Girard et al 2011 ; Szabolcsi et al 2017 ) and the reticular nucleus of the thalamus (data gained from the ABA). The genes that are expressed in these regions are remarked in the last three columns of Table 4 .…”

“…This list was then screened online for genes that were restricted to the area corresponding to the PV2 cluster (Table 4 ). Additionally, the results were compared to previous gene expression analyses, which included the region of the parvafox nucleus and the reticular thalamic nucleus (Girard et al 2011 ; Szabolcsi et al 2017 ), a region enriched with Parv expressing neurons (Table 4 ).…”

“…This cell group–coined the parvafox nucleus (formerly PV1-Foxb1-nucleus (Alvarez-Bolado and Celio 2016 )) –consists of a core of parvalbumin (Parv) immunoreactive cells, surrounded by a shell of Foxb1-positive neurons and 10% of the cells express both (Bilella et al 2014 , 2016 ; Meszar et al 2012 ). Unlike most Parv-positive cells in the brain, the neurons within the parvafox nucleus are not GABAergic, but rather utilize glutamate as their neurotransmitter and receive a strong glycinergic input (Girard et al 2011 ; Szabolcsi et al 2017 ). Studies on the parvafox nucleus have revealed a possible role in vocalization (Roccaro-Waldmeyer et al 2016 ; Alvarez-Bolado and Celio 2016 ), analgesia (Siemian et al 2019 ), and body movement (Cola et al 2020 ) but the precise mechanisms that are responsible for the observed effects, as well as the neural pathways involved, remain poorly understood.…”