Medial geniculate body

The medial geniculate body is a small, oval prominence of the posterior thalamus and forms the principal thalamic component of the auditory pathway. In the human brain, it projects from the caudal diencephalon and lies beneath the pulvinar. It is related ventrolaterally to the lateral geniculate body.

The medial geniculate body is connected inferiorly with the inferior colliculus through the brachium of the inferior colliculus, through which major ascending auditory fibres reach it.

Anatomically, the human medial geniculate body is divided into three major parts: the ventral, dorsal and medial divisions. The ventral division forms the principal lemniscal auditory component; it receives major input from the central nucleus of the inferior colliculus and projects predominantly to the core auditory cortex, including the primary auditory cortex. The dorsal and medial regions have broader connections and participate in more integrative aspects of auditory processing.

Functionally, the medial geniculate body is the major thalamic station for auditory information reaching the cerebral cortex, actively processing auditory signals rather than acting simply as a passive relay.