Electrophysiological identification of tonic and phasic neurons in sensory dorsal root ganglion and their distinct implications inflammatory pain

Title:

Electrophysiological identification of tonic and phasic neurons in sensory dorsal root ganglion and their distinct implications inflammatory pain

Creator:

Yu, Y.-Q., Chen, X.-F., Yang, Y., Yang, F., and Chen, J.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:d2f3d1fa-710c-48bc-bfd3-5125097afe89
uuid:d2f3d1fa-710c-48bc-bfd3-5125097afe89
issn:0862-8408

Subject:

Fyziologie člověka a srovnávací fyziologie, bolest, pain, action potential, dorsal root ganglion, tonic neuron, phasic neuron, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print, bez média, and svazek

Description:

In the mammalian autonomic nervous system, tonic and phasic neurons can be differentiated on firing patterns in response to long depolarizing current pulse. However, the similar firing patterns in the somatic primary sensory neurons and their functional significance are not well investigated. Here, we identified two types of neurons innervating somatic sensory in rat dorsal root ganglia (DRG). Tonic neurons fire action potentials (APs) in an intensity-dependent manner, whereas phasic neurons typically generate only one AP firing at the onset of stimulation regardless of intensity. Combining retrograde labeling of somatic DRG neurons with fluorescent tracer DiI, we further find that these neurons demonstrate distinct changes under inflammatory pain states induced by complete Freund’s adjuvant (CFA) or bee venom toxin melittin. In tonic neurons, CFA and melittin treatments significantly decrease rheobase and AP durations (depolarization and repolarization), enhance amplitudes of overshoot and afterhyperpolarization (AHP), and increase the number of evoked action potentials. In phasic neurons, however, the same inflammation treatments cause fewer changes in these electrophysiological parameters except for the increased overshoot and decreased AP durations. In the present study, we find that tonic neurons are more hyperexcitable than phasic neurons after peripheral noxious inflammatory stimulation. The results indicate the distinct contributions of two types of DRG neurons in inflammatory pain., Y.-Q. Yu, X.-F. Chen, Y. Yang, F. Yang, J. Chen., and Obsahuje bibliografii

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2014 Volume:63 | Number:6

Harvested from:

CDK

Metadata only:

false