Visualization of the NMDA recognition site in rat and mouse spinal cord by [(3)H]CGS 19755in vitro autoradiography

The possibility to visualize the NMDA recognition site with [(3)H]CGS 19755in vitro autoradiography was evaluated in rat brain and spinal cord sections and thereafter used to study the distribution of the NMDA recognition site in rat and mouse spinal cord. The [(3)H]CGS 19755 binding was concentrated to the dorsal horn, in particular to the substantia gelatinosa. Notable binding was also seen in the intermediate area and ventral horn, while some binding was observed in the funiculi. No major differences were seen in [(3)H]CGS 19755 binding at various levels of the rat or mouse spinal cord, although a more dense binding was seen in the mouse. A similar distribution of the [(3)H]CGS 19755 specific binding and the NMDA receptor associated ion-channel site, labeled with [(3)H]TCP, was found in the mouse spinal cord. Taken together, our data indicate that the NMDA recognition site can be visualized in rat and mouse spinal cord byin vitro [(3)H]CGS 19755 autoradiography.