Definition of reticular formation in US English:

reticular formation

(also reticular activating system)


  • A diffuse network of nerve pathways in the brainstem connecting the spinal cord, cerebrum, and cerebellum, and mediating the overall level of consciousness.

    • ‘The spongy degeneration in the brain stem and spinal cord, especially in the reticular formation, has been found to relate closely to learning and memory deficits.’
    • ‘In the central nervous system, the reticular activating system is a major pathway for communication between the brain and the rest of the body.’
    • ‘For example, it is possible that the brainstem reticular formation is divided into the same number of nuclei in all jawed vertebrates.’
    • ‘The mechanisms of arousal involve both direct and indirect connections of receptors with the central nervous system and parts of the reticular formation.’
    • ‘Suggestions for regions of the brain that could be the site of action have included the brain stem reticular formation, the cerebral cortex, and the thalamus.’


reticular formation

/rəˌtikyələr fôrˈmāSH(ə)n/