Statistical analysis
Statistical analysis of immunohistochemical and fibre photometry data
was conducted using GraphPad Prism (version 9.3). Data normality was
assessed using the Shapiro-Wilk test and any outliers identified using
Grubbs’ test were excluded. For the BL/6 experiment investigating the
distribution of BA-NAc neurons responsive to SR and/or SA, data for
neuronal number and density were analyzed using two-way repeated
measures ANOVAs, with a between-subjects factor of stimulus group (No S,
SR, SA) and within-subjects factor of bregma level (from -1.0 to -2.6
mm). Significant interaction or main effects were analyzed using Tukey’s
or Sidak’s multiple comparison post hoc tests. For the TRAPing
experiment investigating intermediate-BA-NAc neuron responsiveness to SR
and/or SA, data for neuronal number were analyzed using two-way repeated
measures ANOVA, with a between-subjects factor of stimulus group (No S,
SR-SA, SA-SR, SR-SR, SA-SA) and within-subjects factor of activity
marker (tdTom, c-Fos). Significant interaction or main effects were
analyzed using Tukey’s or Sidak’s multiple comparison post hoctests. For the fibre photometry experiment, the z-scored
Ca2+ (or EGFP) activity data in peri-event histograms
were collapsed into one mean value for baseline and one mean value per 1
s time bin for the 10 s of post-event data, and a two-way repeated
measures ANOVA was conducted with within-subjects factors of phase
(distal, proximal) and time (from 0 to 10 s). The significant phase x
time interaction effect was analyzed between phases usind Sidak’s
multiple comparison and, within phase, post-event Ca2+activity at each 1 s time bin was compared with baseline using Dunnett’s
multiple comparison test. Data are presented as mean ± SEM. Statistical
significance was set at p ≤ 0.05.
Results