Amygdalar neuronal responses to peripheral nociceptive stimuli in rats

Amygdala plays a very important role in the mediation of pain. In the present study the behaviour of the amygdalar neurons in response to various peripheral noxious stimuli was observed. Noxious mechanical, thermal, electrical, chemical and the non-noxious stimuli (touch) were applied individually to the animal and then the neuronal responses to these stimuli were recorded. Our results showed that the majority of amygdalar units recorded from medial, lateral and basolateral nuclei, responded to different peripheral noxious (thermal, electrical, chemical mechanical) and non-noxious stimuli by excitation. However few neurons decreased their activity on stimulation. Some of these neurons also exhibited after discharge following application of higher intensity of noxious stimuli.