Neuronal receptive field properties in feline nucleus reticularis gigantocellularis

Nucleus reticularis gigantocellularis (NGC) has been shown, using both behavioral and physiological techniques, to be involved in the processing of nociceptive information. However, previous studies of the receptive fields of NGC neurons have utilized only innocuous stimuli. Thus, while neurons in NGC may play an important role in nociception, the receptive field properties of these cells remain to be defined. This investigation was designed to determine the receptive field properties of neurons in NGC using nociceptive and innocuous stimuli. Receptive fields were determined for 127 neurons in NGC. Eighty-seven percnet of the NGC neurons studied responded exclusively to noxious stimuli, while 13% also responded to innocuous stimuli. None of the neurons studied responded exclusively to innocuous stimuli. The receptive fields of most NGC neurons (63%) were large, discontinuous, and bilaterally symmetrical. Eighty-one percent of NGC neurons received convergent inputs from both spinal and trigeminal systems. These receptive field properties differ from those previously reported using only innocuous stimulation.