Neurotransmitters in the vestibular system

Neuronal networks that are linked to the peripheral vestibular system contribute to gravitoinertial sensation, balance control, eye movement control, and autonomic function. Ascending connections to the limbic system and cerebral cortex are also important for motion perception and threat recognition, and play a role in comorbid balance and anxiety disorders. The vestibular system also shows remarkable plasticity, termed vestibular compensation. Activity in these networks is regulated by an interaction between: (1) intrinsic neurotransmitters of the inner ear, vestibular nerve, and vestibular nuclei; (2) neurotransmitters associated with thalamocortical and limbic pathways that receive projections originating in the vestibular nuclei; and (3) locus coeruleus and raphe (serotonergic and nonserotonergic) projections that influence the latter components. Because the ascending vestibular interoceptive and thalamocortical pathways include networks that influence a broad range of stress responses (endocrine and autonomic), memory consolidation, and cognitive functions, common transmitter substrates provide a basis for understanding features of acute and chronic vestibular disorders.