What is the Origin of Nicotinic Receptors?

The term originated in pharmacology and neurophysiology, where researchers classified acetylcholine receptors based on their selective activation by nicotine, distinguishing them from muscarinic receptors. The understanding of these receptors was fundamental to establishing the principles of synaptic transmission. Their discovery illuminated a key pathway for rapid signal transmission in the nervous system.

What is the Mechanism of Nicotinic Receptors?

Upon binding of acetylcholine or nicotine, the receptor protein undergoes a conformational change, opening a central pore that allows the rapid, passive flow of cations across the cell membrane down their electrochemical gradient. In the adrenal medulla, activation of these receptors by preganglionic sympathetic neurons triggers the release of catecholamines, such as epinephrine and norepinephrine, directly influencing the body's acute stress response and metabolic state. Their function is a direct link between the nervous and endocrine systems.

Nicotinic Receptors ∞ Area

Nicotinic Receptors

Meaning

Nicotinic receptors are a class of ligand-gated ion channels that are highly responsive to the neurotransmitter acetylcholine, as well as to the exogenous alkaloid nicotine, hence their name. These receptors are widely distributed throughout the central and peripheral nervous systems, including the neuromuscular junction and the ganglia of the autonomic nervous system. Their activation leads to a rapid influx of positive ions, primarily sodium, causing depolarization and the propagation of an action potential. They are critical for muscle contraction, cognitive function, and the regulation of adrenal hormone release.