Fig. 2: Topographically organized ALM-SC circuits show a gradient of stimulus, choice, and movement activity.

a Left, silicon probe recordings in ALM and SC. b Recording tracks labeled and aligned into the CCF (Methods). An example recording track in SC with single units (green dots, n = 8 units). c Calculating selectivity using correct and error trials. Significant selectivity is tested with three-way ANOVA (Methods). d Example neurons in SC selective for stimulus, choice, and movement (Methods). For stimulus- and choice-selective neurons, raster and peristimulus time histograms (PSTHs) are shown for correct and error trials. Licking movement neurons show spike rate modulation during rhythmic licking cycles. e Left, spatial map of ALM stimulus-selective neurons (n = 336), choice-selective neurons (n = 464), and licking movement neurons (n = 208). Dot size indicates the strength of selectivity stimulus- and choice-selective neurons and spike rate modulation for licking movement neurons. White dots show all recorded neurons. Right, medial-lateral (ML) distribution of selective neurons. The fraction of neurons is relative to all recorded neurons within each bin. The distribution of stimulus-selective neurons differs significantly from licking movement neurons (p < 0.001, permutation test, bootstrap, Methods); the distribution of choice-selective neurons differs significantly from licking movement neurons (p < 0.05, bootstrap). f Same as b for SC stimulus-selective neurons (n = 41), choice-selective neurons (n = 70), and licking movement neurons (n = 264). The ML distribution of stimulus-selective neurons differs significantly from licking movement neurons (p < 0.01, permutation test, bootstrap); the distribution of choice-selective neurons differs significantly from licking movement neurons (p < 0.01, bootstrap). g Labelling of ALM projection neurons. Left, two-colored anterograde tracer injections to map descending projections. Right, fluorescence profiles along the ML axis. Individual lines reflect individual cases (n = 6). h Localization of ALM projection zones in SC. Left, coronal section showing projections from the medial (green) and lateral (red) ALM. Right, fluorescence profiles along the ML axis and anterior-posterior (AP) axis. Lines, individual injection cases (n = 6). i. Localization of SC projection neurons. Left, coronal section showing SC thalamus-projecting neurons (green) and IRt-projecting neurons (red). Right, distributions of SC thalamus-projecting neurons and IRt-projecting neurons. Lines, individual injection cases (n = 3).