Fig. 2.

Effects of orexin A (an agonist of OX₁R and OX₂R) and [Ala¹¹-D-Leu¹⁵]orexin B (a selective agonist of OX₂R) on cyclic AMP formation in primary neuronal cell cultures from rat cerebral cortex stimulated by forskolin (a), PACAP27 (b), and VIP (c). Values are expressed as percent of the response to forskolin, PACAP27, and VIP, and are means ± SEM (n = 8–16). Cyclic AMP accumulation: experiments with forskolin—control cultures, 0.86 ± 0.12% conversion (n = 18); forskolin (1 μM) stimulated cultures, 3.39 ± 0.22% conversion (n = 20); experiments with PACAP27—control cultures, 0.83 ± 0.14% conversion (n = 16); PACAP27 (0.1 μM) stimulated cultures, 5.09 ± 0.42% conversion (n = 24); experiments with VIP—control cultures, 0.88 ± 0.15% conversion (n = 16); VIP (3 μM) stimulated cultures, 4.52 ± 0.26% conversion (n = 20)