Hypocretin-1 activates G proteins in arousal-related brainstem nuclei of rat
Related Experiment Video
Updated: Oct 1, 2026

Recording Gamma Band Oscillations in Pedunculopontine Nucleus Neurons
Published on: September 14, 2016
René Bernard1, Ralph Lydic, Helen A Baghdoyan
1Department of Pharmacology, University of Michigan, 7433 Medical Sciences Building 1, 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA.
Abstract:
The hypocretin (hcrt) ligand-receptor system contributes to the maintenance of wakefulness. Hypocretin receptors are coupled to guanine nucleotide binding (G) proteins and the present study tested the hypothesis that hcrt-1 would activate G proteins in rat brainstem nuclei known to regulate arousal states. In vitro [35S]GTPgammaS autoradiography was performed using coronal brain stem sections from six rats. Hcrt-1 (200 nM) significantly increased [35S]GTPgammaS binding over basal levels in locus coeruleus (24%), dorsal raphe nucleus (12%), pontine reticular nucleus, oral part (28%), and pontine reticular nucleus, caudal part (40%). This is the first study to quantify and localize hcrt-1-induced G protein activation in specific brain stem nuclei. The finding that hcrt-1 stimulated [35S]GTPgammaS binding suggests that some hcrt receptors in pontine brain stem couple to inhibitory G proteins.
Related Concept Videos
Functional Brain Systems: Reticular Formation
Within the reticular formation, there are several distinct nuclei that can be classified into three broad categories. The Raphe nuclei are located along the midline of the brainstem. They are primarily known for their role in synthesizing and releasing serotonin, a neurotransmitter involved in regulating mood, appetite, sleep, and circadian rhythms. The...
Brainstem: Control Centers of Medulla
Olivary Nucleus
The olivary nucleus, or inferior olivary nucleus, is located within the ventrolateral part of the medulla oblongata. It is primarily involved in motor coordination and motor learning. The olivary nucleus receives input from the spinal cord, cerebellum, and motor...
Diencephalon: Hypothalamus and Coordination
The hypothalamus interacts with other brain regions, including the pituitary gland, through a direct physical connection called the hypothalamic-pituitary axis. The hypothalamus receives somatic and visceral inputs and...
GPCRs Regulate Adenylyl Cylase Activity
Two...
Sympathetic Signaling
Sympathetic preganglionic fibers release the neurotransmitter acetylcholine (ACh) onto the ganglionic neurons in the...
Activation and Inactivation of G Proteins

