Neuronal Nitric Oxide Synthase Regulates Cerebellar Parallel Fiber Slow EPSC in Purkinje Neurons by Modulating STIM1-Gated TRPC3-Containing Channels

Le Gui; Vasiliki Tellios; Yun-Yan Xiang; Qingping Feng; Wataru Inoue; Wei-Yang Lu

doi:10.1007/s12311-024-01683-0

Neuronal Nitric Oxide Synthase Regulates Cerebellar Parallel Fiber Slow EPSC in Purkinje Neurons by Modulating STIM1-Gated TRPC3-Containing Channels

Cerebellum. 2024 Mar 12. doi: 10.1007/s12311-024-01683-0. Online ahead of print.

Authors

Le Gui^#¹, Vasiliki Tellios^#², Yun-Yan Xiang¹, Qingping Feng³, Wataru Inoue^{4

5

6}, Wei-Yang Lu^{7

8

9}

Affiliations

¹ Robarts Research Institute, University of Western Ontario, 1151 Richmond Street North, London, ON, N6A 5B7, Canada.
² Graduate Program of Neuroscience, University of Western Ontario, 1151 Richmond Street North, London, ON, N6A 5B7, Canada.
³ Department of Physiology and Pharmacology, University of Western, Ontario1151 Richmond Street North, London, ON, N6A 5B7, Canada.
⁴ Robarts Research Institute, University of Western Ontario, 1151 Richmond Street North, London, ON, N6A 5B7, Canada. winoue@uwo.ca.
⁵ Graduate Program of Neuroscience, University of Western Ontario, 1151 Richmond Street North, London, ON, N6A 5B7, Canada. winoue@uwo.ca.
⁶ Department of Physiology and Pharmacology, University of Western, Ontario1151 Richmond Street North, London, ON, N6A 5B7, Canada. winoue@uwo.ca.
⁷ Robarts Research Institute, University of Western Ontario, 1151 Richmond Street North, London, ON, N6A 5B7, Canada. wlu53@uwo.ca.
⁸ Graduate Program of Neuroscience, University of Western Ontario, 1151 Richmond Street North, London, ON, N6A 5B7, Canada. wlu53@uwo.ca.
⁹ Department of Physiology and Pharmacology, University of Western, Ontario1151 Richmond Street North, London, ON, N6A 5B7, Canada. wlu53@uwo.ca.

^# Contributed equally.

PMID: 38472628
DOI: 10.1007/s12311-024-01683-0

Abstract

Responding to burst stimulation of parallel fibers (PFs), cerebellar Purkinje neurons (PNs) generate a convolved synaptic response displaying a fast excitatory postsynaptic current (EPSC_Fast) followed by a slow EPSC (EPSC_Slow). The latter is companied with a rise of intracellular Ca²⁺ and critical for motor coordination. The genesis of EPSC_Slow in PNs results from activation of metabotropic type 1 glutamate receptor (mGluR1), oligomerization of stromal interaction molecule 1 (STIM1) on the membrane of endoplasmic reticulum (ER) and opening of transient receptor potential canonical 3 (TRPC3) channels on the plasma membrane. Neuronal nitric oxide synthase (nNOS) is abundantly expressed in PFs and granule neurons (GNs), catalyzing the production of nitric oxide (NO) hence regulating PF-PN synaptic function. We recently found that nNOS/NO regulates the morphological development of PNs through mGluR1-regulated Ca²⁺-dependent mechanism. This study investigated the role of nNOS/NO in regulating EPSC_Slow. Electrophysiological analyses showed that EPSC_Slow in cerebellar slices of nNOS knockout (nNOS^-/-) mice was significantly larger than that in wildtype (WT) mice. Activation of mGluR1 in cultured PNs from nNOS^-/- mice evoked larger TRPC3-channel mediated currents and intracellular Ca²⁺ rise than that in PNs from WT mice. In addition, nNOS inhibitor and NO-donor increased and decreased, respectively, the TRPC3-current and Ca²⁺ rise in PNs. Moreover, the NO-donor effectively decreased TRPC3 currents in HEK293 cells expressing WT STIM1, but not cells expressing a STIM1 with cysteine mutants. These novel findings indicate that nNOS/NO inhibits TRPC3-containig channel mediated cation influx during EPSC_Slow, at least in part, by S-nitrosylation of STIM1.

Keywords: Cerebellum; Neuronal nitric oxide synthase; Parallel fiber; STIM1; Slow EPSC; TRPC3.

Grants and funding

MOP-133504/CAPMC/ CIHR/Canada