The reticular formation is a complex network of brainstem nuclei and neurons that serves as a major integration and relay center for many vital brain systems to coordinate functions necessary for survival. It is a set of interconnected nuclei located throughout the brainstem, and it is not anatomically well-defined because it includes neurons located in different parts of the brain. The reticular formation is highly organized, but intricate and complex, and it contains various nuclei along with numerous ascending and descending tracts. Some of the functions of the reticular formation include:
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Arousal and Consciousness: The reticular formation is the primary regulator of arousal and consciousness, and it promotes arousal and consciousness through the reticular activating system.
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Somatic Motor Control: The reticular formation is involved in somatic motor control, and it coordinates the activity of neurons in the cranial nerve nuclei, which are responsible for motor movements in the face and head, as well as motor movements related to autonomic functions of the visceral organs.
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Cardiovascular Control: The reticular formation is involved in cardiovascular control, and it coordinates the activity of neurons in the respiratory centers that control the muscles of respiration.
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Pain Modulation: The reticular formation is one means by which pain signals from the lower body reach the cerebral cortex, and it is also the origin of the descending analgesic pathways.
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Sleep and Wakefulness: The reticular formation is involved in regulating sleep and wakefulness, and it normally suppresses the individuals level of arousal during sleep.
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Coordination of Reflexes: The reticular formation functions as an integration, relay, and coordination center for many vital life functions and controls many of the protective reflexes.
The reticular formation is a very diverse structure, and its activity extensively modulates cortical excitability, both in physiological conditions and in disease.
