The core-matrix theory of thalamus, first proposed by Ted Jones in 1998, states that neurons in the thalamus belong to either a parvalbumin-immunopositive core of precisely projecting neurons, or to a calbindin-immunopositive matrix of diffusely and widely projecting neurons.[1][2]
Neurons comprising the core are believed to be involved in propagation of 'driving' information, whereas neurons comprising the matrix are believed to play a more modulatory role.[3]: 1612 The cortical interactions of core neurons maintain content and enable perceptual constancy, whereas through reciprocal interactions with deep-layer cortical neurons, matrix neurons support wakefulness and determine perceptual thresholds.[3]: 1611