This study was undertaken to examine the laminar distribution of spinotelencephalic tract neurons in the rat, by means of retrograde fluorescent labelling and to estimate the role of NADPH-diaphorase-reactive spinal cells as sources of spino-supraspinal pathways in the rat. The localization, size and shape of some neurons were similar in both labelling methods. Cells were mostly multipolar in the medial part of nucl. proprius, and fusiform and spindle-shaped in lamina I and X. It is suggested that some of the NADPH-d (+) neurons in the deep dorsal horn and lamina X are sources of a spino-supraspinal pathway to nucleus accumbens and the excitability and spontaneous activity of these dynamic neurons may be higher when spinally mediated hyperalgesia is developed.

This study was undertaken to examine the laminar distribution of spinotelencephalic tract neurons in the rat, by means of retrograde fluorescent labelling and to estimate the role of NADPH-diaphorase-reactive spinal cells as sources of spino-supraspinal pathways in the rat. The localization, size and shape of some neurons were similar in both labelling methods. Cells were mostly multipolar in the medial part of nucl. proprius, and fusiform and spindle-shaped in lamina I and X. It is suggested that some of the NADPH-d (+) neurons in the deep dorsal horn and lamina X are sources of a spino-supraspinal pathway to nucleus accumbens and the excitability and spontaneous activity of these dynamic neurons may be higher when spinally mediated hyperalgesia is developed.