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hypothalamic–pituitary portal system

a system of blood capillaries that transports releasing hormones from the hypothalamus to the anterior pituitary. Also called hypothalamic–hypophyseal portal system. See also hypothalamic–pituitary–adrenal axis.

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Psychology term of the day

November 18th 2024

center–surround antagonism

center–surround antagonism

a characteristic of the receptive fields of many visual and somatosensory neurons in which stimulation in the center of the receptive field evokes opposite responses to stimulation in the periphery. Thus, some neurons depolarize with center stimulation and hyperpolarize when the same stimulus appears in the surrounding region of the receptive field, whereas other neurons have the opposite pattern of responses. Center–surround antagonism greatly increases the sensitivity of the nervous system to contrast. See also off response; on response; simple cell.