Abstract
The diaminopyridines (DAP) increase the activity recorded in the dorsal roots of an isolated hamster spinal cord preparation. Treatment with AP increased the activity simultaneously recorded in the dorsal and ventral roots, but whilst that in the dorsal root continued after washing away the amino pyridine, that in the ventral root ceased for a period of time. There are indications that the amino pyridines may differently affect dorsal and ventral interneurones.