Melatonin reduces neuronal loss and cytoskeletal deterioration: implications for Psychiatry
Salud ment
;
32(1): 3-11, Jan.-Feb. 2009.
Artigo
em Inglês
|
LILACS-Express
| LILACS
| ID: lil-632684
ABSTRACT
This review article summarizes the potential role of circadian rhythmicity and melatonin in psychiatric disorders. The melatonin rhythm, with high blood levels at night and low values during the day, is a reflection of the biological clock, i.e., the suprachiasmatic nucleus (SCN). The SCN receive information about the prevailing light dark conditions from specialized ganglion cells (only 1-2% of the total ganglion cells) in the retina. These unique cells contain a newly-discovered photopigment, melanopsin, which responds to a rather narrow band width of light that peaks at roughly 480 nm. The axons of these ganglion cells project via the retinohypothalamic tract through the optic nerve to the SCN, located just above the optic chiasm in the anterior hypothalamus. Via this pathway, light detected by the retina synchronizes the circadian clock to precisely 24 hours. In the absence of light, i.e., darkness, the SCN signals the pineal gland to produce melatonin via a complex neural pathway that involves fibers that project from the hypothalamus to the preganglionic sympathetic neurons in the intermediolateral cell column of the upper thoracic cord. Axons of these neurons exit the spinal cord to eventually synapse on neurons in the superior cervical ganglia. Then, postganglionic fibers convey the information to the pineal gland mediating the nighttime rise in melatonin synthesis. Because melatonin is only elevated at night, it is referred to as the <RESUMEN
La melatonina (N-acetil-5-metoxitriptamina) es una indolamina que produce la glándula pineal durante la noche. Se libera directamente en la circulación general con un ritmo circadiano. En las enfermedades psiquiátricas se presentan alteraciones en los ritmos biológicos. La melatonina es un cronobiótico ya que sincroniza los ritmos biológicos como el ciclo sueño-vigilia, el de la temperatura corporal y el ciclo de liberación de cortisol, con el fotoperiodo. Esta indolamina no actúa como un hipnótico clásico. Los efectos que ejerce sobre el sueño son acortar su latencia, prolongar el periodo de sueño natural y reducir los despertares nocturnos. Por lo anterior, se ha descrito como un compuesto que <
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Tipo de estudo:
Estudo prognóstico
Idioma:
Inglês
Revista:
Salud ment
Assunto da revista:
Psiquiatria
Ano de publicação:
2009
Tipo de documento:
Artigo
País de afiliação:
México
/
Estados Unidos
Instituição/País de afiliação:
Instituto Nacional de Psiquiatria, Ramon de la Fuente Muñiz/MX
/
University of Texas Health Science Center/US
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