Divergence in Single Unit Responses during Learning in the Odor Discrimination Task

<div><p>(A) Raster plot of single unit spike times organized per block for the ten rewarded trials (A, left column) and ten unrewarded trials (AB, right column). Timing and duration of odor exposure is indicated on the <i>x</i>-axis by the red bar.</p> <p>(B) PSTH of the data shown in (A). Red lines on either side of the histogram indicate +/− standard error of the mean (SEM). The bin size in the PSTH is 0.15 s. This means that the firing rate in Hz is the value in the <i>y</i>-axis × (1/0.15).</p> <p>(C) Behavioral performance—percent correct as a function of block number—for the animal from whom the cell in (A) and (B) was recorded.</p> <p>(D) A plot of the firing-rate increase above background to odor A (red) and odor AB (blue) in each block of the behavior. The points represent the firing rate in spikes/0.15-s bin during odor exposure (0.5 to 2.5 s) minus the rate in spikes/0.15-s bin in the period immediately before odor exposure (−1 to 0 s). Error bars denote the mean +/− SEM of each point (ten trials per point).</p> <p>(E) The lower right hand pie chart shows what percent of the responses were inhibitory (gray), excitatory (yellow), or mixed (blue). A mixed response was defined as a response to either odor A or AB that had both an excitatory and inhibitory component or a response that was excitatory to one odor and inhibitory to the other odor stimulus.</p>