Figure 8.
Average discharge rates across sleep–wake stages of different cell types and subgroups in relation to EEG and EMG activity. A, WP-max cells discharged maximally during aW and PS when EEG gamma amplitude was maximal (as shown on right for cell c74u03) across sleep–wake stages. They included cholinergic (Nb+/ChAT+ cell c30u13 from (Lee et al., 2005b)), GABAergic (Nb+/GAD+ cell c78u10 from Fig. 4) and putative glutamatergic (Nb+/ChAT−/GAD− cell c74u03) BF neurons, whose discharge rate was positively correlated with gamma activity (r = 0.76, 0.81, and 0.84, respectively) and could thus promote cortical activation during W and PS. B, S-max cells discharged maximally during SWS when EEG delta amplitude was maximal (as shown on right for cell c104u01) across sleep–wake stages. They included GABAergic (Nb+/GAD+ cell c120u04 from Fig. 5) and putative glutamatergic (Nb+/ChAT−/GAD− cell c104u01) BF neurons, whose discharge rate was positively correlated with delta activity (r = 0.60 and 0.74, respectively) and could thus promote delta activity and/or reciprocally dampen gamma activity during SWS. C, P-max cells discharged maximally during PS when EMG amplitude was minimal (as shown on right for c70u12) across sleep–wake stages. They included GABAergic (Nb+/GAD+ cell c78u11 from Fig. 6) and putative glutamatergic (Nb+/ChAT−/GAD− cell c70u12) BF neurons, whose discharge rate was negatively correlated with EMG amplitude (r = −0.53 and −0.57, respectively) and could thus promote muscle atonia along with behavioral quiescence during sleep. D, W-max cells discharged maximally during aW when EMG amplitude was maximal (as shown on right for c106u05) across sleep–wake stages. They included only putative glutamatergic (Nb+/ChAT−/GAD− cell, c106u05 from Fig. 7) BF neurons, whose discharge rate was positively correlated with EMG amplitude (r = 0.49) and could thus promote muscle tone along with behavioral arousal during waking. Bar charts of unit average discharge rates present data from representative cells of each subgroup (see Table 3), and those of EEG and EMG amplitudes (right) present corresponding data from the Nb+/ChAT−/GAD− cells.