The rostral ventrolateral medulla (RVLM), also known as the

pressor An antihypotensive agent, also known as a vasopressor agent or simply vasopressor, or pressor, is any substance, whether endogenous or a medication, that tends to raise low blood pressure. Some antihypotensive drugs act as vasoconstrictors to in ...

area of the

medulla Medulla or Medullary may refer to: Science * Medulla oblongata, a part of the brain stem * Renal medulla, a part of the kidney * Adrenal medulla, a part of the adrenal gland * Medulla of ovary, a stroma in the center of the ovary * Medulla of t ...

, is a brain region that is responsible for basal and reflex control of sympathetic activity associated with

cardiovascular The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...

function. Abnormally elevated sympathetic activity in the RVLM is associated with various

cardiovascular disease Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, h ...

s, such as

heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...

and

hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high bl ...

. The RVLM is notably involved in the

baroreflex The baroreflex or baroreceptor reflex is one of the body's homeostatic mechanisms that helps to maintain blood pressure at nearly constant levels. The baroreflex provides a rapid negative feedback loop in which an elevated blood pressure causes the ...

. It receives inhibitory GABAergic input from the caudal

ventrolateral medulla The ventrolateral medulla, part of the medulla oblongata of the brainstem, plays a major role in regulating arterial blood pressure and breathing. It regulates blood pressure by regulating the activity of the sympathetic nerves that target the heart ...

(CVLM). The RVLM is a primary regulator of the

sympathetic nervous system The sympathetic nervous system (SNS) is one of the three divisions of the autonomic nervous system, the others being the parasympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of th ...

; it sends catecholaminergic projections to the sympathetic

preganglionic neuron In the autonomic nervous system, fibers from the CNS to the ganglion are known as preganglionic fibers. All preganglionic fibers, whether they are in the sympathetic division or in the parasympathetic division, are cholinergic (that is, these ...

s in the

intermediolateral nucleus The intermediolateral nucleus (IML) is a region of grey matter found in one of the three grey columns of the spinal cord, the lateral grey column. This is Rexed lamina VII. The intermediolateral cell column exists at vertebral levels T1 – L ...

of the spinal cord via

reticulospinal tract The reticular formation is a set of interconnected nuclei that are located throughout the brainstem. It is not anatomically well defined, because it includes neurons located in different parts of the brain. The neurons of the reticular formation ...

Physostigmine Physostigmine (also known as eserine from ''éséré'', the West African name for the Calabar bean) is a highly toxic parasympathomimetic alkaloid, specifically, a reversible cholinesterase inhibitor. It occurs naturally in the Calabar bean and ...

, a choline-esterase inhibitor, elevates

endogenous Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, es ...

levels of

acetylcholine Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Part ...

and causes a rise in blood pressure by stimulation of the RVLM.Medullary pressor area: site of action of intravenous physostigmine
/ref>

Orexinergic Orexin (), also known as hypocretin, is a neuropeptide that regulates arousal, wakefulness, and appetite. The most common form of narcolepsy, type 1, in which the individual experiences brief losses of muscle tone ("drop attacks" or cataplexy), ...

neurons from the

lateral hypothalamus The lateral hypothalamus (LH), also called the lateral hypothalamic area (LHA), contains the primary orexinergic nucleus within the hypothalamus that widely projects throughout the nervous system; this system of neurons mediates an array of cognit ...

output in the RVLM.

References

{{Reflist Sympathetic nervous system Reflexes Medulla oblongata Cardiovascular physiology

See also

References