Optogenetics: the light as a tool for the study of brain function in the mechanisms of the sleep-wake and eating behavior
Por:
Salin-Pascual, Rafael J.
Publicada:
1 may 2015
Resumen:
Optogenetics is a technology that uses the effect of light on
photosensitive ion channels. These can be opened, as in the case of
rhodopsin channel-2 (ChR2), with a net effect of depolarization, or as
the channel of halo rhodopsin, NpHR, in which light produces an
inhibition of ionic currents. Currently there are more molecular tools
of this type, which are used for in vitro, ex vivo and animal studies,
which express this type of cell membrane proteins, by genetic
manipulation (knock-in). Articles that used this type of optogenetic
technology was reviewed, especially those of the role of two
neuropeptides that regulate from the lateral hypothalamus different
sleep stages and eating behavior. Orexins, also called hypocretins, are
two neuropeptides, which selectively suppress sleep and sleep with rapid
eye movement (REM sleep). Mutation in one of their receptors, orexin
subtype two, has detected as the agent in Doberman dogs narcolepsy.
While narcolepsy in humans, it has been proposed as autoimmune disease.
The other neuropeptide studied was melanin-concentrating hormone (MCH),
which is also located in the lateral hypothalamus. Their function in
sleep is to increased REM sleep, and promoting feeding behavior by
calorie deficiencies. While orexin have a role on the consumption of
palatable foods, even when calorie needs are already met. The knowledge
of optogenetics confirmed by the interaction of these two neuropeptides
in the regulation of sleep and eating behavior, can help to understand
health problems such as childhood morbid obesity, where sleep deficiency
correlates inversely with the increase the body mass index.
Filiaciones:
Salin-Pascual, Rafael J.:
Univ Nacl Autonoma Mexico, Fac Med, Sistema Nacl Investigadores, Dept Psiquiatria Salud Mental, Mexico City 04510, DF, Mexico
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