The localization of the thalamic relay in the specific sensory path from the tongue of the cat.

Abstract

Summary.1. The thalamic relay nucleus in the specific sensory path from the tongue was localized in the medial part of nucleus ventralis posteromedialis of the cat.2. The center of the nucleus was found within a region defined by the following Horsley‐Clarke coordinates: frontally, 9 to 10, laterally, 4 to 5 and dorso‐ventrally, 0 to 1.3. The focal potential evoked by electrical stimulation of the tongue was recorded with microelectrodes in 0.25 mm steps along tracks through the thalamus of encéphale isolé preparations. The potential was evoked within a well localized region not exceeding 2 mm in diameter. The overlap with the nearby region of nucleus ventralis posteromedialis containing the tactile face relays was of the order of 0.2 mm.4. Responses to tactile, thermal and gustatory stimulation of the tongue were observed within the thalamic relay nucleus.