Relations between the spontaneous firing rate and taste responsiveness of the dog cortical neurons.

The breadth of responsiveness and the spontaneous discharge rates of dog cortical neurons to 4 taste stimuli (NaCl, tartaric acid, sucrose and quinine-HCl) were examined and compared to thalamic neurons. Spontaneous rates were higher in the cortex, and there was a smaller breadth of responsiveness. There were common tendencies observed in both thalamus and cortex; more narrowly tuned taste neurons and neurons having inhibitory responses had higher spontaneous rates. However, as shown by across-neuron correlations, the ability of cortical neurons to discriminate among the 4 tastes was less influenced by the level of spontaneous activity than thalamic neurons.