(a) Stimulating electrodes were implanted in NBM to recruit the cortical afferent cholinergic system, and ECoG wires were placed to detect NBM-evoked cortical activation (Online Methods). M1-CNiFERs and control CNiFERs were implanted in separate sites in neocortex, whereas cholinergic terminals were widely distributed and imaged acutely or chronically using TPLSM. WM, white matter. Right, two-photon microscopy images of M1-CNiFERs (cyan) and control CNiFERs (red) implanted in rat motor cortex in 25–50-μm diameter columns. Data represent a z projection from 40–60 μm below the cortical surface. There are ~10–20 CNiFER cells per site in this field of view. (b) M1-CNiFER FRET responses (lower) and ECoG activity (upper) evoked by increasing levels of NBM electrical stimulation. Cortical activation appeared as a shift from large- to small-amplitude waves. Control CNiFERs were nonresponsive. (c) The M1-CNiFER response to NBM stimulation was strongly correlated with loss of power in the ECoG δ band, quantified as the z score–normalized logarithm of the reciprocal of the power, −log[power in ECoG δ band], for each animal (Online Methods). CNiFER responses were defined as the area under the curve of ΔR/R for 10 s after the stimulus normalized to that of 10 s before the stimulus (n = 55 trials with 4 animals).
Leave a Reply