Knock-down of Cav3.2 has no effect on morphine-induced alleviation of heat and mechanical hypersensitivity.

<p>Ca_v3.2 T-channels in sensory neurons were knocked down with intrathecal administration (every 12 hrs for a total of 4 doses) of oligodeoxynucleotide (AS) specific for the Ca_v3.2 T-channels. Controls were given mismatch oligodeoxynucleotide (MIS). Heat hyperalgesia was quantified with PWLs (A, right paw; B, left paw) and mechanical hypersensitivity was measured using PWRs (C, right paw; D, left paw). The response to morphine (10 mg/kg, i.p.) in AS-treated diabetic rats mimicked the response in MIS-treated diabetic rats in that both groups exhibited change of PWLs and PWRs at around 1–2 hrs post morphine injection (†, p<0.001 compared with before injection in A and B; †, p<0.05 compared to before injection in C and D) except that there was a notable upward shift in the PWLs and a downward shift in the PWRs in AS-treated diabetic rats due to Ca_V3.2 T-channel knock down (*, p<0.05; **, p<0.01; ***, p<0.001 in AS vs. MIS treatment; n = 3 rats per data point).