We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Evidence for Two Subpopulations of Cerebrospinal Fluid-Contacting Neurons with Opposite GABAergic Signaling in Adult Mouse Spinal Cord.
- Authors
Rionde, Priscille; Jurčić, Nina; Mounien, Lourdes; Ibrahim, Stéphanie; Ramirez-Franco, Jorge; Stefanovic, Sonia; Trouslard, Jérôme; Wanaverbecq, Nicolas; Seddik, Riad
- Abstract
Spinal cerebrospinal fluid-contacting neurons (CSF-cNs) form an evolutionary conserved bipolar cell population localized around the central canal of all vertebrates. CSF-cNs were shown to express molecular markers of neuronal immaturity into adulthood; however, the impact of their incomplete maturation on the chloride (Cl-) homeostasis as well as GABAergic signaling remains unknown. Using adult mice from both sexes, in situ hybridization revealed that a proportion of spinal CSF-cNs (18.3%) express the Na+-K+-Cl- cotransporter 1 (NKCC1) allowing intracellular Cl- accumulation. However, we did not find expression of the K+-Cl- cotransporter 2 (KCC2) responsible for Cl- efflux in any CSF-cNs. The lack of KCC2 expression results in low Cl- extrusion capacity in CSF-cNs under high Cl- load in whole-cell patch clamp. Using cell-attached patch clamp allowing recordings with intact intracellular Cl- concentration, we found that the activation of ionotropic GABAA receptors (GABAA-Rs) induced both depolarizing and hyperpolarizing responses in CSF-cNs. Moreover, depolarizing GABA responses can drive action potentials as well as intracellular calcium elevations by activating voltage-gated calcium channels. Blocking NKCC1 with bumetanide inhibited the GABAinduced calcium transients in CSF-cNs. Finally, we show that metabotropic GABAB receptors have no hyperpolarizing action on spinal CSF-cNs as their activation with baclofen did not mediate outward K+ currents, presumably due to the lack of expression of G-protein-coupled inwardly rectifying potassium (GIRK) channels. Together, these findings outline subpopulations of spinal CSF-cNs expressing inhibitory or excitatory GABAA-R signaling. Excitatory GABA may promote the maturation and integration of young CSF-cNs into the existing spinal circuit.
- Subjects
GABAERGIC neurons; SPINAL cord; ACTION potentials; POTASSIUM channels; CALCIUM channels; GLUTAMATE receptors; INTRACELLULAR calcium; CELL populations
- Publication
Journal of Neuroscience, 2024, Vol 44, Issue 22, p1
- ISSN
0270-6474
- Publication type
Article
- DOI
10.1523/JNEUROSCI.2289-22.2024