Figure 9.

Histograms of single neuron activity in the MGm during presentations of the 400 ms tone conditioned stimulus in the last paired training session. Three examples are displayed for the groups trained on P17–P19 (top row), P24–P26 (middle row), or P31–P33 (bottom row). Stimulus-elicited activity is greater in the neurons recorded from the older groups relative to the neurons recorded from the P17–P19 group during the first 100 ms of the tone stimulus and during the last 200 ms of the stimulus for some of the neurons. Stimulus onset is depicted by the vertical gray line.