Central Cholinergic Neurons Are Rapidly Recruited by Reinforcement Feedback - PubMed (original) (raw)

Figure 1. Optogenetic tagging of central cholinergic neurons

A, Auditory projecting cholinergic neurons are in the caudal nucleus basalis (NB; Fig. S1), which includes the ventromedial globus pallidus (GP) and the caudal substantia innominata (SI). Top, coronal section with increasing magnification. ChAT-Cre mouse; green, neurons infected with AAV-flex-GFP; red, ChAT staining; white arrowhead, location of neurons enlarged on the right. Scale bars; left, 1 mm; right, 50 μm. Bottom, retrograde labeling from the auditory cortex. Red, cholinergic neurons; green, retrograde Lumaflour beads; yellow, double labeled neurons. Scale bar, 150 μm. CPu, caudate putamen; int, internal capsule; Rt, reticular thalamic nucleus. B, Left, coronal sections showing expression of virally transfected ChR2-eYFP in the caudal NB (top) and horizontal limb of the diagonal band (HDB; bottom). Scale bar, 1 mm. Middle, enlarged images of the marked areas. Right, reconstructed location of identified cholinergic neurons projected onto two coronal planes (top, NB; bottom, HDB; numbers, antero-posterior distance from bregma). Different symbols indicate individual mice. VP, ventral pallidum. C, Left, spike raster of an identified cholinergic neuron aligned to light stimulation (blue line). Right, peri-stimulus time histograms aligned to photostimulation onset (blue line) for all identified cholinergic neurons (normalized by peak value, sorted by peak latency; all pulses of the most efficient stimulation frequency were used; colors from black to white correspond to higher firing rates). D, Cumulative histograms of light-evoked spike latency (left) and jitter (right) for all identified cholinergic neurons. E, SALT (stimulus-associated spike latency test) for optical tagging showed strongly bimodal p-value distribution (blue, p<0.01). F, Left, example recording of a cholinergic neuron in an awake freely moving mouse. Top, spike times; middle, auditory local field potential (LFP); bottom, wavelet spectrogram of the LFP. Right, example recording of the same cell during sleep. Note the lower firing rate and delta oscillations in the auditory LFP. G, Median firing rate of cholinergic neurons was highest in awake freely moving epochs, lower in quiet wakefulness and lowest during sleep. Black lines, individual cells; solid lines, significantly different firing rate (p<0.01, Mann-Whitney test).