retinohypotalamiska

The retinohypothalamic tract is a neural pathway that connects the retina of the eye to the suprachiasmatic nucleus (SCN) of the hypothalamus. This pathway is crucial for regulating circadian rhythms, the body's internal biological clock.

Light entering the eye stimulates specialized photoreceptor cells in the retina called intrinsically photosensitive retinal ganglion cells (ipRGCs). These cells contain a photopigment called melanopsin, which is sensitive to light, particularly blue light. When stimulated by light, ipRGCs send signals along the retinohypothalamic tract.

These signals travel directly to the SCN, which is located in the hypothalamus. The SCN acts as the master clock for the body, coordinating a wide range of physiological processes that occur on a roughly 24-hour cycle, including sleep-wake patterns, hormone release, body temperature, and metabolism.

The retinohypothalamic tract provides the SCN with information about the external light-dark cycle, allowing it to synchronize the body's internal clock with the environment. This synchronization is essential for maintaining healthy sleep patterns and overall physiological well-being. Disruptions to this pathway, such as those caused by prolonged exposure to artificial light at night or shift work, can lead to circadian rhythm disorders and associated health problems.