A) In this neuron the facilitation of IPSCs by local superfusion of noradrenaline (NA, 50 μM, shown in upper trace) and systemic dexmedetomidine is blocked by spinal application of the α1-adrenoceptor antagonist prazosin (10 μM, lower trace). Data in A were obtained from the same neurons shown in Fig. 4A.
B) There was a strong correlation between the facilitatory actions of spinal noradrenaline and systemic dexmedetomidine on spontaneous IPSCs evoked in the same SG neurons (linear regression R2 = 0.96).
C) Summary chart showing the facilitatory action of systemic dexmedetomidine on spontaneous IPSCs which is blocked in the presence of spinal prazosin (an α1 antagonist, 10 μM) but not by yohimbine (an α2 antagonist, 4 μM).