Position and organization of thalamic cellular activity during diencephalic recording. I. Pressure-evoked activity.

With the aid of a computer graphic display technique, data gathered from exploratory diencephalic recordings in 130 stereotactic operative procedures are presented to show the location and somatotopography of 'pressure'-evoked cellular responses. In addition, the variable position of these responses in relation to common diencephalic landmarks is presented. Our findings indicate that response points are more compact when related to a common posterior commissure (PC) and lie in a sickle-shaped zone 14-16 mm lateral to the midline and 2-8 mm rostral to anatomically the nucleus ventralis caudalis or the nucleus ventralis intermedius. Somatotopographically, face responses were medial to the leg.