Figure 5. Differential influence of neocortical and MECIII UDS on CA1 activity.

a) Example trace of an MECIII neuron’s membrane potential (red), along with the simultaneously recorded neocortical LFP (gray) and CA1 MUA rate (green). b) Average relative power spectra of MECIII membrane potential (red), LECL3 membrane potential (blue), neocortical (Ncx) LFP (black), and CA1 MUA (green). The MECIII neurons’ membrane potential had peak power at significantly lower frequencies (0.29 ± 0.018 Hz) compared to the neocortical LFP (0.46 ± 0.014 Hz; p=6.9×10−8), while peak frequencies of LECL3 neurons’ power spectra (0.41 ± 0.030 Hz) were not significantly different from the neocortical LFP (p=0.38). c) The strength of CA1 MUA modulation by MECIII UDS is plotted against the strength of modulation by neocortical UDS. While MECIII Up states had a strong, significantly positive modulatory effect on CA1 MUA (0.75 ± 0.094 z; p=1.2×10−4), neocortical Up states had a much weaker (p=1.2×10−4), and significantly inhibitory effect (−0.16 ± 0.066; p=0.013). The solid black line shows the diagonal.