Open AccessNeuroanatomical characterization of Gαi2-expressing neurons in the hypothalamic paraventricular nucleus of male and female Sprague-Dawley rats
Author(s) -
Parul Chaudhary,
Richard D. Wainford
Publication year - 2021
Publication title -
physiological genomics/physiological genomics (print)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.078
H-Index - 112
eISSN - 1531-2267
pISSN - 1094-8341
DOI - 10.1152/physiolgenomics.00097.2020
Subject(s) - colocalization , medicine , parvocellular cell , endocrinology , hypothalamus , gabaergic , vasopressin , biology , tyrosine hydroxylase , in situ hybridization , neuropeptide , nucleus , periventricular nucleus , neuroscience , arcuate nucleus , receptor , messenger rna , dopamine , biochemistry , inhibitory postsynaptic potential , gene
Hypertension is a global health burden. The hypothalamic paraventricular nucleus (PVN) is an essential component of the neuronal network that regulates sodium homeostasis and blood pressure (BP). Previously, we have shown PVN-specific G protein-coupled receptor-coupled Gαi 2 subunit proteins are essential to counter the development of salt-sensitive hypertension by mediating the sympathoinhibitory and natriuretic responses to increased dietary sodium intake to maintain sodium homeostasis and normotension. However, the cellular localization and identity of PVN Gαi 2 -expressing neurons are currently unknown. In this study using in situ hybridization, we determined the neuroanatomical characterization of Gαi 2 -expressing PVN neurons in 3-mo-old male and female Sprague-Dawley rats. We observed that Gαi 2 -expressing neurons containing Gnai2 mRNA are highly localized in the parvocellular region of the hypothalamic PVN. At level 2 of the hypothalamic PVN, Gnai2 mRNA colocalized with ∼ 85% of GABA-expressing neurons and ∼28% of glutamatergic neurons. Additionally, within level 2 Gnai2 mRNA colocalized with ∼75% of corticotrophin-releasing hormone PVN neurons. Gnai2 neurons had lower colocalization with tyrosine hydroxylase (∼33%)-, oxytocin (∼6%)-, and arginine vasopressin (∼10%)-expressing parvocellular neurons in level 2 PVN. Colocalization was similar among male and female rats. The high colocalization of Gnai2 mRNA with GABAergic neurons, in conjunction with our previous findings that PVN Gαi 2 proteins mediate sympathoinhibition, suggests that Gαi 2 proteins potentially modulate GABAergic signaling to impact sympathetic outflow and BP.