page_title: Suprachiasmatic nucleus
section_title: Other signals from the retina
hierarchical_section_title: Suprachiasmatic nucleus / Other signals from the retina
caption_attribution_description: English: Diagram illustrating the influence of dark-light rythms on circadian rythms and related physiology and behavior.
context_page_description: The suprachiasmatic nucleus or nuclei is a tiny region of the brain in the hypothalamus, situated directly above the optic chiasm. It is responsible for controlling circadian rhythms. The neuronal and hormonal activities it generates regulate many different body functions in a 24-hour cycle. The mouse SCN contains approximately 20,000 neurons.
  The SCN interacts with many other regions of the brain. It contains several cell types and several different peptides and neurotransmitters.
context_section_description: The SCN is one of many nuclei that receive nerve signals directly from the retina.
  Some of the others are the lateral geniculate nucleus (LGN), the superior colliculus, the basal optic system, and the pretectum:
  The LGN passes information about color, contrast, shape, and movement on to the visual cortex and itself signals to the SCN.
  The superior colliculus controls the movement and orientation of the eye.
  The basal optic system also controls eye movements.
  The pretectum controls the size of the pupil.
caption: A variation of an eskinogram showing the influence of light and darkness on circadian rhythms and related physiology and behavior through the SCN in humans
exif: {}