کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6262557 | 1613804 | 2016 | 11 صفحه PDF | دانلود رایگان |
- MrgprA3+ neurons generate less action potential than MrgprA3â neurons.
- MrgprA3+ neurons have larger potassium currents than MrgprA3â neurons.
- MrgprA3â neurons innervating skin are similar to those innervating other tissues.
Itch is described as an unpleasant or irritating skin sensation that elicits the desire or reflex to scratch. MrgprA3, one of members of the Mrgprs family, is specifically expressed in a subpopulation of dorsal root ganglion (DRG) in the peripheral nervous system (PNS). These MrgprA3-expressing DRG neurons have been identified as itch-specific neurons. They can be activated by the compound, chloroquine, which is used as a drug to treat malaria. In the present study, we labeled these itch-specific neurons using the method of molecular genetic markers, and then studied their electrophysiological properties. We also recorded the cutaneous MrgprA3â neurons retrogradely labeled by Dil dye (MrgprA3â-Dil). We first found that MrgprA3+ neurons have a lower excitability than MrgprA3â neurons (MrgprA3â-non-Dil and MrgprA3â-Dil). The number of action potential (AP) was reduced more obviously in MrgprA3+ neurons than that of in MrgprA3â neurons. In most cases, MrgprA3+ neurons only generated single AP; however, in MrgprA3â neurons, the same stimulation could induce multiple AP firing due to the greater voltage-gated potassium (Kv) current existence in MrgprA3+ than in MrgprA3â neurons. Thus, Kv current plays an important role in the regulation of excitability in itch-specific neurons.
Journal: Brain Research - Volume 1636, 1 April 2016, Pages 161-171