Effects of central orexin 1 receptor blockade on locus coeruleus neurons with lateral hypothalamic input

Abstract

The locus coeruleus (LC) receives a major orexinergic input and is densely packed with orexin 1 receptors (OX 1 ‐R). Here we examined the effects of central administration of an OX 1 ‐R antagonist on lateral hypothalamic (LH) stimulation‐induced activation of LC neurons. All experiments were conducted using male Sprague Dawley rats under initial isoflurane (1.7–1.9%) anaesthesia followed by urethane (1.3–1.4 g/kg, i.v.). Electrical stimulation of the LH (0.5 Hz, twin 0.5 ms pulses, 3 ms interpulse interval, 300uA) evoked excitatory responses in all LC neurons studied (n = 24) as judged by construction of peri‐sti..