The Matrix-Core theory of thalamus, first proposed by Ted Jones, states that neurons in the thalamus belong to either a calbindin-immunopositive matrix of diffusely and widely projecting neurons, or to a parvalbumin-immunopositive core of precisely projecting neurons [1]. The 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.