A. Fano factor, a measure of trial-to-trial variability, increased from V1 to POR
to LA→POR. Insets show single-trial food cue response
timecourses from an example POR neuron (left) and
LA→POR axon (right) in individual
sessions.
B. Single-trial FC responses of V1, POR, and LA→POR neurons
often depended on trial history. Colored lines represent responses to a FC when
preceded by another FC, grayscale lines represent responses to the FC when
preceded by one (dark) or many (lighter) non-FCs (QC or NC).
C. Neurons in all three areas showed modulation of FC responses based on trial
history, with greater proportions exhibiting large trial history effects in POR
and LA→POR
vs. V1. A positive trial history modulation index value
indicates greater FC response when preceded by a non-FC. Pie charts show
fraction of neurons with positive (red), negative (blue), significantly positive
(dark red) or significantly negative (dark blue) index values. Neurons outlined
in black are example neurons from (B). For display purposes, all values >3 or
<-3 were set to 3 and −3, respectively.
D. Cumulative distributions of the magnitude of index values, confirming that, as
with hunger modulation, V1 neurons showed far less modulation by trial history
than POR and LA→POR neurons (p=0.03, V1
vs. POR; p<0.001 V1 vs.
LA→POR; Kruskal-Wallis).