Figure 3From: Esmolol modulates inhibitory neurotransmission in the substantia gelatinosa of the spinal trigeminal nucleus of the rat The increase in miniature inhibitory postsynaptic current (mIPSC) frequency by esmolol was dependent on extracellular Ca 2+. (A and B) Top: the membrane current recording of a neuron of the caudal part of the spinal trigeminal nucleus in the presence (A) and in the absence (B) of extracellular Ca2+. Esmolol (500 μM) was applied at the horizontal bars. Recordings with "CsCl-based" internal solution. Bottom of A and B: time-expanded continuous traces taken at points 1 and 2 indicated in the top traces showing the control and the peak effects of drugs. (C) Summery of the effects of esmolol on mIPSC frequency. *, P < 0.001; Mann Whitney's U-test. NS, not significantly different; vs. pre-administration control values. The numbers in the bars indicate the number of neurons analyzed. The horizontal broken lines indicate the control values (100%).Back to article page