Fig. 2: Optogenetic stimulation of Purkinje cells can substitute for a US to drive learning.
From: Climbing fibers provide essential instructive signals for associative learning
a, Experimental scheme. L7-Cre;ChR2 mice were used to photostimulate Purkinje cells, which served as a US for conditioning. b, Example coronal section of cerebellar cortex indicating fiber placement in the eyelid area of the cerebellar cortex (white arrow) and labeling Purkinje cell ChR2 expression (green) and calbindin (magenta). Similar expression and fiber placement were observed in 11 mice. c, Example electrophysiological traces of Purkinje cell SSpks (gray dots) and CSpks (red dots) in response to Pkj-ChR2 laser stimulation (orange shading). d, Population histogram of SSpk rate (gray) and CSpk probability (p(CSpk)) (red; n = 44 trials, N = 2 cells from 2 mice) (see Extended Data Fig. 2d for statistics). e, Average eyelid closures ± s.e.m. (shadows) evoked by low and medium-power Pkj-ChR2 stimulation. Note the blink at stimulus offset. Peak amplitude of evoked blink: low versus medium power, *P = 0.047, paired Student’s t-test (N = 4 mice). f, Average eyelid closures ± s.e.m. (shadows) on CS + US trials in the first training session showing the blink evoked by Pkj-ChR2-US laser stimulation (N = 4 mice). g, The %CR across training sessions ± s.e.m. (shadows) to a Pkj-ChR2 US (N = 4 mice, plotted as in Fig. 1j). h, Average eyelid traces ± s.e.m. (shadows) from CS-only trials of sessions 2, 4 and 7 of the experiments in g.
