Coding of object location in the vibrissal thalamocortical system.

In whisking rodents, object location is encoded at the receptor level by a combination of motor and sensory related signals. Recoding of the encoded signals can result in various forms of internal representations. Here, we examined the coding schemes occurring at the first forebrain level that receives inputs necessary for generating such internal representations--the thalamocortical network.

Lemniscal and Extralemniscal Compartments in the VPM of the Rat.

The ventral posteromedial thalamic nucleus (VPM) of the rat contains at least two major vibrissa-representing compartments: the dorsomedial (VPMdm), which belongs to the lemniscal afferent pathway, and the ventrolateral (VPMvl), which belongs to the extralemniscal afferent pathway. Although input-output projections and functional characteristics that distinguish these two compartments were recently clarified, a comprehensive structural analysis of these compartments and the border between them was lacking. This paper addresses structural and functional relationships between the VPMdm and VPMvl.