Figure 3. Effect of 5-HT₃ receptor ligands on vagal afferent-evoked activation of NTS neurones.

A, response of an NTS neurone to electrical stimulation of the vagus nerve at •. The traces show 5 superimposed sweeps of extracellular recorded neuronal activity evoked at a latency typical of nonmyelinated afferents, before (i) control, and during (ii) ionophoretic administration of PBG. B, post-stimulus time histograms (20 sweeps, 1 ms bins) of vagal afferent-evoked activity of an NTS neurone showing (i) control evoked activity (ii) and potentiation of this activity during the ionophoretic administration of PBG.