Selfinhibition

Selfinhibition, also called autoinhibition, refers to processes by which a system reduces its own activity through internal feedback or regulatory elements. It is a form of negative feedback that helps maintain homeostasis, prevent runaway activity, and shape the dynamics of cellular and physiological responses.

In biochemistry, self-inhibition occurs when the product of a pathway inhibits an earlier enzyme (feedback inhibition). Enzymes can also carry autoinhibitory domains that block the active site until the appropriate signal relieves the block. Such regulation ensures proportional responses and prevents excessive flux through a pathway. Kinases and proteases frequently use autoinhibition as a regulatory strategy, and dysregulation of these mechanisms can contribute to disease.

In neuroscience, neurons use autoreceptors on the presynaptic terminal to respond to their own neurotransmitter and dampen release or synthesis. Classic examples include dopamine D2 autoreceptors and serotonin autoreceptors. These self-regulatory loops help tune signaling strength, prevent transmitter depletion, and shape responses to sustained activity.

In genetics and cellular regulation, some transcription factors repress their own expression, creating negative feedback loops that stabilize gene expression levels during development and in mature cells. In broader contexts, self-inhibition is a general principle of control systems, where internal checks limit output to maintain stability and safety.