DOUBLE FLUORESCENT LABELING STUDY ON THE SPINOSOLITARY TRACT-DORSAL COLUMN POSTSYNAPTIC NEURONS IN RATS / 解剖学报

ABSTRACT

Electrophysiological studies have shown that the spinosolitary tract-dorsal column postsynaptic (SST-DCPS) neurons may project to both the dorsal column and solitary tract nuclei. In order to demonstrate the neurons morphologically, fluorescein dyes, PI and Bb, were injected into the dorsal column nuclei and the solitary tract nucleus respectively. A total 282 cells were found to be retrogradely labeled in the spinal dorsal horn in 10 adult rats. Of them, 51 (18%) cells were PI-Bb doubly labeled; 120 (43%) were PI labled alone; and 111 (39%) were Bb singly labled. Most of these double-labled cells were concentrated in laminae III-V. The existence of double projection neurons that project to both the dorsal column and solitary tract nuclei, namely the physiologically identified SST-DCPS neurons, is morphologically confirmed in the present study. These neurons may transmit information to both visceral and somatic sensory nuclei, indicating they may play an important role in the convergence of somato-visceral afferents.