galactorrhea

n. abnormal expression of breast milk, which may occur either in women at times other than when nursing or in men. Lactation is stimulated by the pituitary hormone prolactin, and the neurotransmitter dopamine normally acts to inhibit the release of prolactin. Therefore, administration of dopamine-receptor antagonists (e.g., conventional antipsychotics), which inhibit the effects of dopamine, may cause galactorrhea. Pituitary tumors or injury to the pituitary gland, causing excessive secretion of prolactin, may also result in galactorrhea. The dopamine-receptor agonist bromocriptine may be used to treat the condition.

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Psychology term of the day

March 16th 2025

Hering theory of color vision

a theory of color vision postulating that there are three sets of receptors, one of which is sensitive to white and black, another to red and green, and the third to yellow and blue. The breaking down (catabolism) of these substances is supposed to yield one member of these pairs (white, red, or yellow), while the building up (anabolism) of the same substances yields the other (black, green, or blue). Color blindness results from the absence of one or more of the chromatic processes. See opponent process theory of color vision. [proposed in 1875 by Ewald Hering]