Anterior trigeminothalamic tract

The anterior trigeminothalamic tract, a.k.a. the ventral trigeminothalamic tract is a crucial component of the trigeminal lemniscus, representing second-order neurons within the trigeminal sensory system. Primarily, these neurons originate from the spinal trigeminal nucleus and are responsible for transmitting sensory information related to pain and temperature from the face and head. The fibers in this tract decussate, or cross over, and ascend to relay this information to the ventral posterior medial (VPM) nucleus of the thalamus on the contralateral side.

Additionally, some fibers within the anterior trigeminothalamic tract come from the principial sensory nucleus. These fibers, having decussated, convey sensory information regarding touch and pressure from the face and head. However, these fibers are relatively few compared to the pain and temperature fibers. In contrast, most second-order neurons from the main sensory nucleus do not decussate; instead, they ascend ipsilaterally (as posterior or dorsal trigeminothalamic tract) to the VPM nucleus of the thalamus on the same side. Following processing in the thalamus, the sensory information is projected to the cerebral cortex for further interpretation and response.