Centrally expressed Cav3.2 T-type calcium channel is critical for the initiation and maintenance of neuropathic pain
Sophie L. Fayad, Guillaume Ourties, Benjamin Le Gac, Baptiste Jouffre, Sylvain Lamoine, Antoine Fruquière, Sophie Laffray, Laïla Gasmi, Bruno Cauli, Christophe Mallet, Emmanuel Bourinet, Thomas Bessaïh, Régis C. Lambert, Nathalie Leresche
Abstract
Cav3.2 T-type calcium channel is a major molecular actor of neuropathic pain in peripheral sensory neurons, but its involvement at the supraspinal level is almost unknown. In the anterior pretectum (APT), a hub of connectivity of the somatosensory system involved in pain perception, we show that Cav3.2 channels are expressed in a subpopulation of GABAergic neurons coexpressing parvalbumin (PV). In these PV-expressing neurons, Cav3.2 channels contribute to a high-frequency-bursting activity, which is increased in the spared nerve injury model of neuropathy. Specific deletion of Cav3.2 channels in APT neurons reduced both the initiation and maintenance of mechanical and cold allodynia. These data are a direct demonstration that centrally expressed Cav3.2 channels also play a fundamental role in pain pathophysiology.