Neurosekretoriske

Neurosekretoriske (neurosecretory) describes cells or processes in which neurons produce and release hormones, or neurohormones, into the circulatory system rather than across a synapse. This arrangement couples the nervous and endocrine systems, enabling neural activity to regulate hormonal signals over longer distances and timescales.

The best-known neurosecretory pathway is the hypothalamic–pituitary axis. Hypothalamic neurosecretory neurons release releasing and inhibiting hormones into the hypophyseal portal system, which transports them to the anterior pituitary and modulates secretion of hormones such as thyroid-stimulating hormone, adrenocorticotropic hormone, growth hormone, and gonadotropins. In the posterior pituitary, the axons of hypothalamic neurons terminate in capillaries and release neurohormones—vasopressin (antidiuretic hormone) and oxytocin—directly into the bloodstream.

Other neurosecretory tissues include the pineal gland, where pinealocytes release melatonin in response to neural signals to regulate circadian rhythms; and the adrenal medulla, where sympathetic stimulation triggers chromaffin cells to secrete epinephrine and norepinephrine into the blood as part of the systemic stress response. Neurosecretory mechanisms also operate in various brain regions, contributing to the broader regulation of physiology beyond the pituitary axis.

Key features of neurosecretory signaling include the synthesis of peptide or amine hormones by neurons, release into capillaries or perivascular spaces, and action as circulating hormones. This contrasts with classic neurotransmission, which primarily affects adjacent cells. Disruptions can affect growth, metabolism, reproduction, water balance, and stress responses.