Alasregulaatioon

Alasregulaatioon, a Finnish term, translates to "down-regulation" in English and refers to a biological process where a cell or organism reduces its response to a stimulus. This can occur when a receptor on the cell surface is exposed to a high concentration of a signaling molecule for an extended period. In response, the cell may decrease the number of receptors on its surface, making it less sensitive to further stimulation. Alternatively, the cell might alter the signaling pathway downstream of the receptor, diminishing the overall effect.

This mechanism is crucial for maintaining homeostasis and preventing overstimulation. For instance, in the nervous system, neurotransmitter receptors can undergo down-regulation in response to prolonged exposure to neurotransmitters, helping to regulate neuronal activity and prevent excitotoxicity. Similarly, hormone receptors can be down-regulated when hormone levels are consistently high, preventing excessive physiological responses. This process is a fundamental aspect of cellular adaptation and plays a vital role in various physiological and pathological conditions. It is a dynamic process that allows biological systems to adjust their sensitivity and responsiveness to changing environmental conditions or internal signals.