(1) Sensory systems are generally presumed to convey peripheral afferent signals to the central nervous system with a high degree of fidelity.(2) In addition, the dorsal central column of primary afferent fibers within the spinal cord appears susceptible to the inhibitory effects of hypoxia in rats.(3) Hypoxia could disturb respiratory afferent pathways and neural processing at more than one level.(4) Cough is mediated by the interaction of sensory afferent nerves, central cough reflexes, and local axon reflexes.(5) There is increasing support for the idea that in asthma the efferent and afferent nerve fibers may be changed in their capacity to be stimulated.(6) In addition, cholinergic afferents can be stimulated by a variety of mediators involved in allergen-induced airway inflammation.(7) It may also be the site of projection of proprioceptive afferents from the respiratory muscles and chest wall.(8) These afferents bypass the olfactory neuropil in the antennal lobe to project into the antennal mechanosensory and motor centers.(9) Muscle receptor afferents are involved in the level and timing of respiratory activity.(10) Proprioceptor afferents project to the phrenic motor neurons and affect their firing rate.
