SNAP [N-(acetyloxy)-3-nitrosothiovaline] potentiates inhibitory activity in a voltage-clamp recording from a dorsal lateral geniculate nucleus (dLGN) relay neuron. A: histograms showing the frequency and amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs) in artificial cerebrospinal fluid (ACSF), after SNAP application (500 µM), wash, and in SR95531 [2-(3-carboxypropyl)-3-amino-6-methoxyphenyl-pyridazinium bromide, 10 µM]. Histograms here and in subsequent figures were constructed using 5-s bins. B: representative traces in control conditions, after SNAP application, wash, and in the presence of SR95531 from neuron in A. Note the increase in frequency of outward (inhibitory) events after SNAP application. After recovery of the SNAP-mediated response, SR95531 completely attenuated the sIPSCs. C: population data for 3 different SNAP concentrations (20 µM, n = 7; 100 µM, n = 7; and 500 µM, n = 17). D: these graphs illustrate the peak effect of SNAP on sIPSC amplitude (filled bar) and frequency (open bar). *P < 0.01.