SINGLE-CELL RESPONSES OF THE NUCLEUS OF THE TRANSPEDUNCULAR TRACT IN RABBIT TO MONOCHROMATIC LIGHT ON THE RETINA

Abstract

Recordings were made from single cells of this nucleus (NTPT) of responses to monochromatic light on the retina. Seven non-albino, hybrid animals were studied under photopic conditions (both urethane and encephale isole preparations). Cells of the NTPT were found maximally responsive to two wavelengths, 461 [plus or minus] 3.7 m[mu] and 501 [plus or minus] 3.9 m[mu]. Rarely did a cell respond to wavelengths longer than 600 m[mu]. Two maxima were found in the latency spectrum of the nucleus, as was the case for the main visual pathway (lateral geniculate nucleus), suggesting a retinal origin for the distribution. About half of the NTPT cells displayed regular spontaneous background activity, facilitated or inhibited by monochromatic light. Recording sites were verified histologically.