Sensory response of the anterior cingulate cortex to peripheral stimulation in adult rats. A-B, diagram of in vivo recording from the anterior cingulate cortex (ACC) in an anaesthetized rat; animals were maintained in a lightly anaesthetized state by halothane. The recording electrode was placed into the ACC contralateral to the peripheral stimulation electrode. Amputation (the removal of the third digit of the hindpaw) was performed on the non-stimulated hindpaw. During amputation, a higher concentration of halothane was used. C, Long-lasting enhancement following amputation of a single hindpaw digit A, representative traces of EPSPs 5 min before amputation (Pre) and 115-120 min after (Post) sham treatment or amputation. The he latency of sensory responses was not changed after the amputation, while the EPSP slope was increased. D, amputation of a single digit of the contralateral hindpaw (indicated by an arrow) caused long-lasting enhancement of sensory responses (•). Sensory responses were not significantly changed in sham-treated animals (○). The test stimulation frequency was 0.01 Hz (from Reference 54).