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Updated: Aug 24, 2026

In-Vivo Calcium Imaging of Sensory Neurons in the Rat Trigeminal Ganglion
Published on: February 9, 2024
Histamine-induced Ca(2+) influx via the PLA(2)/lipoxygenase/TRPV1 pathway in rat sensory neurons
Byung Moon Kim1, Sang Hee Lee, Won Sik Shim
1Sensory Research Center, National Creative Research Initiatives, College of Pharmacy, Seoul National University, San 56-1, Shinlim, Kwanak-Gu, Seoul 151-742, South Korea.
Abstract:
Histamine is known to excite a subset of C-fibers and cause itch sensation. Despite its well-defined excitatory action on sensory neurons, intracellular signaling mechanisms are not understood. Previously, we demonstrated that bradykinin excited sensory neurons by activating TRPV1 via the phospholipase A(2) (PLA(2)) and lipoxygenase (LO) pathway. We, thus, hypothesized that histamine excited sensory neurons via the PLA(2)/LO/TRPV1 pathway. Application of histamine elicited a rapid increase in intracellular Ca(2+) ([Ca(2+)](i)) that desensitized slowly in cultured dorsal root ganglion neurons. Histamine-induced [Ca(2+)](i) was dependent on extracellular Ca(2+) and inhibited by capsazepine and by SC0030, competitive antagonists of TRPV1. Quinacrine and nordihydroguaiaretic acid, a PLA(2) and an LO inhibitor, respectively, blocked the histamine-induced Ca(2+) influx in sensory neurons, while indomethacin (a cyclooxygenase inhibitor) did not. We thus conclude that histamine activates TRPV1 after stimulating the PLA(2)/LO pathway, leading to the excitation of sensory neurons. These results further provide an idea for potential use of TRPV1 antagonists as anti-itch drugs.
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