Figure 2.

Taste responses can be observed in GC. A, The top half shows raster plots of spiking activity of a single representative GC neuron in response to presentation of the four basic tastes (sucrose, green; quinine, black; citric acid, red; NaCl, pink). Each row is a single trial, and each dot is an action potential. Below are the corresponding PSTHs, which show the firing rate in spikes/second (y-axis) of the neuron's response to taste; x-axis, poststimulus time in milliseconds. Zero is the moment of taste delivery, marked with a vertical dashed line. B, A second representative neuron's response to the same tastes. C, The percentage of GC neurons (y-axis) that are taste-responsive (gray), taste-selective (black), and palatability-related (dashed) when BLA is intact (x-axis, poststimulus time in ms). Because each trace reflects an analysis involving a sliding window, some smoothing has necessarily occurred. D, The number of neurons (y-axis) responding to each of the four tastes (x-axis) during the Intact Middle and Late epochs; somewhat fewer neurons respond to each taste in the Late epoch. E, The number of neurons (y-axis) that responded to a particular number of taste stimuli (x-axis) during the Intact Middle and Late epochs.