Central cough reflex pathways

The central cough reflex pathways represent a complex neural network primarily located in the medulla oblongata of the brainstem, serving as the integration center for the cough reflex [1][2]. This network receives afferent sensory input from the airways via the vagus nerve, specifically terminating in the nucleus tractus solitarius (NTS) and the paratrigeminal nucleus [2][4]. Once the sensory threshold is reached, the central cough generator coordinates a precise sequence of motor outputs to the respiratory muscles to produce a cough [1][5]. Higher brain regions, including the cerebral cortex, also interact with these pathways to provide voluntary control or suppression of the reflex [3]. In various respiratory diseases, these central pathways can become hypersensitized (central sensitization), leading to chronic or excessive coughing [4]. Therapeutic agents targeting these pathways, such as opioids and certain NMDA antagonists, work by elevating the cough threshold, though they often carry risks of central nervous system side effects like sedation and respiratory depression [3][5].

Other names

Medullary cough centerCentral cough generatorBrainstem cough networkCough reflex arc

Centrally acting drugs modulate the cough reflex by increasing the activation threshold of the medullary cough center [1][3]. This is typically achieved through the agonism of mu-opioid receptors (e.g., codeine) or sigma-1 receptors (e.g., dextromethorphan), which inhibits the transmission of cough signals in the nucleus tractus solitarius (NTS) [2][3]. Other mechanisms include the enhancement of inhibitory GABAergic signaling or the blockade of excitatory NMDA or NK1 receptors within the brainstem network [4].