Experimental Brain Research

, Volume 176, Issue 2, pp 227–236 | Cite as

Prostaglandin E2 potentiates the excitability of small diameter trigeminal root ganglion neurons projecting onto the superficial layer of the cervical dorsal horn in rats

  • Jun Kadoi
  • M. Takeda
  • S. Matsumoto
Research Article


The aim of the present study was to investigate how prostaglandin E2 (PGE2) affects the excitability of trigeminal root ganglion (TRG) neurons, projecting onto the superficial layer of the cervical dorsal horn, using fluorescence retrograde tracing and perforated patch-clamp techniques. TRG neurons were retrogradely labeled with fluorogold (FG). The cell diameter of FG-labeled neurons was small (< 30 μm). Under the voltage-clamp mode, application of PGE2 (0.01–10 μM) concentration-dependently increased the magnitude of the peak tetrodotoxin-resistant sodium current (TTX-R I Na) and this current was maximal at a concentration of 1 μM. One micromolar PGE2 application caused a hyperpolarizing shift of 8.3 mV in the activation curve for TTX-R I Na. In the current-clamp mode, the PGE2 (1 μM) application significantly increased the number of action potentials during the depolarizing step pulses as well as the level of overshoot but had no significant effect on the resting membrane potential. These results suggest that the excitability of small diameter TRG neurons seen after 1 μM PGE2 application is involved in an increase in the TTX-R I Na.


Prostaglandin E2 Trigeminal root ganglion Retrograde-labeling C1 neurons TTX-resistant Na+ channel 


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Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  1. 1.Department of Physiology Nippon Dental University, School of Dentistry at TokyoTokyoJapan

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