The cough center is a region of the
brain
The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...
which controls
cough
A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and Microorganism, microbes. As a protective reflex, coughing can be repetitive with the cough reflex fol ...
ing. The cough center is located in the
medulla oblongata
The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun ...
in the
brainstem
The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is conti ...
.
Cough suppressants focus their action on the cough center.
Structure
The exact location and functionality of the cough center has remained somewhat elusive: while
Johannes Peter Müller
Johannes Peter Müller (14 July 1801 – 28 April 1858) was a German physiologist, comparative anatomist, ichthyologist, and herpetologist, known not only for his discoveries but also for his ability to synthesize knowledge. The paramesonephri ...
observed in 1838 that the medulla coordinates the cough reflex, investigating it has been slow because the usual anaesthetics for experimental animals were morphine or opiates, drugs which strongly inhibit cough. In addition, the center likely overlaps with the
respiratory rhythm
The respiratory center is located in the medulla oblongata and pons, in the brainstem. The respiratory center is made up of three major respiratory groups of neurons, two in the medulla and one in the pons. In the medulla they are the dorsal res ...
generator networks. It is hence not so much a specific area, but a function within the respiration and reflex networks of the brainstem.
Cough receptors project to relay neurones in the
solitary nucleus
The solitary nucleus (SN) (nucleus of the solitary tract, nucleus solitarius, or nucleus tractus solitarii) is a series of neurons whose cell bodies form a roughly vertical column of grey matter in the medulla oblongata of the brainstem. Their a ...
, which project to other parts of the
respiratory networks. In particular, the
pre-Bötzinger complex The preBötzinger complex, often abbreviated as preBötC, is a functionally and anatomically specialized site in the ventral-lateral region of the lower medulla oblongata (i.e., lower brainstem). The preBötC is part of the ventral respiratory group ...
may act as a
pattern generator
A pattern is a regularity in the world, in human-made design, or in abstraction, abstract ideas. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometry, geometric shapes and ...
for the cough response. Parts of the caudal medullary
raphe nucleus
The raphe nuclei (, "seam") are a moderate-size cluster of nuclei found in the brain stem. They have 5-HT1 receptors which are coupled with Gi/Go-protein-inhibiting adenyl cyclase. They function as autoreceptors in the brain and decrease the r ...
(
nucleus raphe obscurus
The nucleus raphe obscurus is one of the medullary raphe nuclei. It is located caudal to the nucleus raphe magnus. The nucleus raphe obscurus projects to the cerebellar lobes VI and VII and to crus II along with the nucleus raphe pontis.
The nucl ...
and
nucleus raphe magnus
The nucleus raphe magnus (NRM) is one of the seven raphe nuclei. It is situated in the pons in the brainstem, just rostral to the nucleus raphe obscurus.
The NRM receives afferent stimuli from the enkephalinergic neurons of the periaqueductal ...
) are known to be essential for the cough response. Other systems that may be involved in pattern generation and regulation are the
pontine respiratory group, the
lateral tegmental field
The tegmentum (from Latin for "covering") is a general area within the brainstem. The tegmentum is the ventral part of the midbrain and the tectum is the dorsal part of the midbrain. It is located between the ventricular system and distinctive b ...
and the deep
cerebellar nuclei
The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or eve ...
. Successful joint models of medullary systems coordinating breathing, coughing and swallowing has been constructed based on this model.
Coughing can occur or be inhibited as a
voluntary action
Voluntary action is an anticipated goal-oriented movement. The concept of voluntary action arises in many areas of study, including cognitive psychology, operant conditioning, philosophy, neurology, criminology, and others. Additionally, voluntary ...
, suggesting control from higher systems in the brain. Functional brain imaging of voluntary, suppressed, and induced coughing show that a number of higher-order brain areas can get involved and may be important even for involuntary coughing. In contrast, voluntary coughing does not seem to activate medullary systems.
[Stuart B. Mazzone, Leonie J. Cole, Ayaka Ando, Gary F. Egan, and Michael J. Farrell. Investigation of the Neural Control of Cough and Cough Suppression in Humans Using Functional Brain Imaging. The Journal of Neuroscience, 23 February 2011, 31(8): 2948-2958; ]
References
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See also
*
Cough reflex
The cough reflex occurs when stimulation of cough receptors in the respiratory tract by dust or other foreign particles produces a cough, which causes rapidly moving air which usually remove the foreign material before it reaches the lungs. This ...
*
Respiratory center
The respiratory center is located in the medulla oblongata and pons, in the brainstem. The respiratory center is made up of three major respiratory groups of neurons, two in the medulla and one in the pons. In the medulla they are the dorsal ...
Medulla oblongata
Respiratory physiology