Related Experiment Video
Updated: Aug 24, 2026

In-Vivo Calcium Imaging of Sensory Neurons in the Rat Trigeminal Ganglion
Published on: February 9, 2024
Subunit-specific P2X-receptor expression defines chemosensory properties of trigeminal neurons
Jennifer Spehr1, Marc Spehr, Hanns Hatt
1Lehrstuhl fuer Zellphysiologie, Ruhr-Universitaet Bochum, Universitaetsstr. 150, 44780 Bochum, Germany.
Abstract:
The facial innervation pattern of trigeminal nerve fibres comprises the innervation of the nasal epithelium, where free trigeminal nerve endings contribute to detection and discrimination of chemical stimuli including odourants. The signal transduction mechanisms in sensory nerve endings underlying perception of chemical stimuli remain widely uncovered. Here, we characterized trigeminal ATP-activated P2X receptors in cultured rat trigeminal neurons and investigated their role in chemoperception. We identified a new subpopulation of neurons lacking typical nociceptive characteristics and expressing homomeric P2X(2) receptors. Using a certain group of chemicals known as trigeminal stimuli we found no direct activation of trigeminal neurons, but a modulation of P2X(2) receptor mediated currents. In contrast, P2X(3) receptor mediated currents of nociceptive trigeminal neurons remained unaffected by the tested chemicals. Therefore, we assume a functional role for the newly identified subpopulation in chemodetection of certain trigeminal stimuli.
Related Concept Videos
G-Protein Gated Ion Channels
Sensory organs,...
Mechanically-gated Ion Channels
Thermosensation
The Physiology of Taste
Cholinergic Receptors: Muscarinic
The subtypes M1, M3, and M5 couple with the Gq subunit and activate the phospholipase C (PLC) activity, mobilizing intracellular Ca2+. Activation...
Introduction to Special Senses

