substantia nigra

a region of gray matter in the midbrain, named for its dark pigmentation, that sends dopaminergic neurons to the basal ganglia. Depletion of dopaminergic neurons in this region is implicated in Parkinson’s disease.

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Psychology term of the day

January 19th 2025

short-wavelength pigment

the photopigment present in one of the three populations of retinal cones that has maximum sensitivity to a wavelength of 419 nm. The absence of the gene for the short-wavelength pigment causes tritanopia, a form of color blindness in which blue and green are confused with one another. See also long-wavelength pigment; medium-wavelength pigment.