Related Experiment Video
Updated: Aug 15, 2026

Optogenetic Manipulation of Neural Circuits During Monitoring Sleep/wakefulness States in Mice
Published on: June 19, 2019
Different neuronal phenotypes in the lateral hypothalamus and their role in sleep and wakefulness
Dmitry Gerashchenko1, Priyattam J Shiromani
1West Roxbury VA Medical Center and Harvard Medical School, 1400 VFW Parkway, West Roxbury, MA 02132, USA. dmitri_gerachtchenko@hms.harvard.edu
Abstract:
The sleep disorder narcolepsy is now linked with a loss of neurons containing the neuropeptide hypocretin (also known as orexin). The hypocretin neurons are located exclusively in the lateral hypothalamus, a brain region that has been implicated in arousal based on observations made by von Economo during the viral encephalitic epidemic of 1916-1926. There are other neuronal phenotypes located in the lateral hypothalamus that are distinct and separate from the hypocretin neurons. Here the authors identify these neurons based on peptides and neurotransmitters that they express and review roles of these neurons in sleep. Given the heterogeneity of the neuronal phenotypes in the lateral hypothalamus, it is likely that hypocretin neurons, as well as other types of neurons in the lateral hypothalamus, influence sleep and provide state-dependent regulation of physiological functions.
Related Concept Videos
Diencephalon: Anatomical Regions
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...
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...
Sleep-Wake Cycles
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
The Pineal Gland
The primary secretion of the pineal gland is the hormone melatonin, derived from serotonin. The concentration of melatonin in the...
Understanding Sleep
The circadian rhythm, a nearly 24-hour cycle, is deeply influenced by environmental light cues. Light exposure directly affects the hypothalamus, which in turn regulates...

