Figure 4.

NE and α₁- and β-agonist infusions within the MSA and MPOA, but not SI, promote waking. Shown are the effects of NE, the α₁-agonist, phenylephrine (PHEN), and the β-agonist, isoproterenol (ISO) infused into MPOA (top and middle panels) or MSA (bottom panel). Symbols represent mean (± SEM) of time (seconds) spent awake in 30-minute (1800-seconds) epochs. PRE1 and PRE2 represent 30-min pre-infusion epochs occurring immediately prior to the infusion. POST1-POST3 represent 30-minute post-infusions epochs, beginning immediately following the infusions. Top Panel: Effects of unilateral infusion of vehicle, 4 nmol NE, or 16 nmol NE, infused into either the MPOA or SI on time spent awake. Middle Panel: Effects of unilateral infusion of vehicle, PHEN (40 nmol) or ISO (15 nmol) infused into either the MPOA or SI on time spent awake. NE, PHEN and ISO increase time spent awake when infused into the MPOA, but not into the SI. The only exception to this was observed with the high dose of NE. In this case the latency to waking was longer, the magnitude of waking smaller and the duration shorter than that observed with infusions into the MPOA. The wake-promoting effects of intra-MPOA infusion of all of these compounds are dose-dependent. Larger effects are observed with bilateral infusions. Similar wake-promoting effects of β and α₁-receptor activation are observed in MSA. Bottom Panel: Effects of vehicle and PHEN (10 nmol, 50 nmol) infusion into the MSA on time spent awake. PHEN exerts dose dependent wake-promoting effects when infused into the MSA. Similar effects were observed with infusion of the β-agonist, ISO. For all panels, a lack of visible error bars indicates the magnitude of the SEM fell within the range corresponding to the dimensions of the symbol. There were no significant differences between any of the groups during the pre-infusion epochs. ^*P<0.05, ^**P<0.01 compared to PRE-1 (from^{31–33, 40}}).