Figure 5
Tongue motor responses elicited by photostimulation across sleep-wake states. Group mean (+SEM) data are shown for Protocol 3 – Power (1, 2, 3, 5, 10, 15 and 20 mW) in ChAT-ChR2(H134R)-EYFP mice (n = 7). These data illustrate the effect of stimulation power on peak elicited tongue muscle activity as a function of applied pulse number in the stimulus train for interventions performed in wakefulness (a), non-REM sleep (b) and REM sleep (c). The symbols ‘#’ indicate a significant difference between the indicated powers in each sleep-wake state from post-hoc tests irrespective of pulse number. The symbol ‘*’ indicates that the responses elicited by the first pulse were significantly larger than all the subsequent pulses (i.e., second through fifth, as well as the last pulse of the train) in each of wakefulness, non-REM and REM sleep. The abbreviation ‘ns’ indicated that the responses elicited by pulse 3 onwards were statistically indistinguishable from each other. The calculated magnitude of Fisher’s Least Significant Difference (LSD, P < 0.05) are also shown for (i) the different powers of stimulation (within a given pulse number), and (ii) the different pulse numbers in the stimulus train (within a given power). Overall, the data show that for each of wakefulness, non-REM and REM sleep the motor responses were larger with higher powers, larger at the beginning of the stimulation train, and with the magnitude of the differences in response increasing from lower to the higher powers within each sleep-wake state. See text for further details.
