Projections of the reticular complex of the thalamus onto physiologically characterized regions of the medial geniculate body.

Afferents from the reticular complex of the thalamus (RE) to the subdivisions of the medial geniculate body (MGB) in the cat were studied by retrograde axonal transport of horseradish peroxidase injected in sites where single unit responses to tones had been characterized. All MGB subdivisions studied received afferents from the same region of RE corresponding to its ventral posterior third, characterized by large neurons. No obvious differences were seen in the localization of labelled neurons within RE according to which MGB subdivision was injected, except that pars lateralis afferents seemed to originate from somewhat more limited portions of RE.