Figure 4.
Upregulation of Ih currents in large DRG neurons from CRP rats. (a) Representative traces of Ih recorded in large DRG neurons from sham (left) and CRP group (middle) in response to hyperpolarizing voltage steps of −50 mV to −120 mV from a holding potential at −60 mV. Ih currents recorded were blocked by bath application of ZD7288 (15 μM). (b) I–V relations of Ih currents in large DRG neurons from sham and CRP group. Note that CRP induces upregulation of Ih currents greatly. (c) The activation curve of Ih from sham and CRP DRG neurons was constructed by measuring tail currents at −120 mV after application of prepulse potentials between −50 and −120 mV (middle inset) and fitted with a Boltzmann equation. (d) and (e) The midpoint (V0.5) for activation of Ih and slope K value in the CRP neurons (red) were not different from that recorded in sham control neurons (black). All data are expressed as mean ± SEM. *P < 0.05 as compared to sham control rats.
CRP: cervical radiculopathic pain.