Abstract View THE INFLUENCE OF PERIPHERAL STIMULATION ON THE PAIRED-PULSE FACILITATION IN THE ANTERIOR CINGULATE CORTEX OF THE RAT

View THE INFLUENCE OF PERIPHERAL STIMULATION ON THE PAIRED-PULSE FACILITATION IN THE ANTERIOR CINGULATE CORTEX OF THE RAT J.-J. Sun; S.-Y. Cheng; S.-L. Chen; S.-C. Chai; B.-C. Shyu* Inst. of Biomedical Sciences, Academia Sinica, Taipei, 115, Taiwan In our previous study, paired-pulse facilitation (PPF) was found in rat s anterior cingulate cortex (ACC) following the stimulation of the medial thalamus (MT). The present study examined the effect of different peripheral stimuli on the PPF in awaked and anaesthetized rats. Electrical paired-pulse stimuli (0.2ms, 300 A, inter-pulse interval, 100ms) were delivered to the MT. Field potentials were recorded in the ACC. In chronic tests, effects of different peripheral stimuli on PPF were measured in awaked, freely moving rats. In acute test, the influence of sciatic nerve electrical stimulation on the PPF was investigated in anesthetized (Pentothal, 6.25mg/100g) rats. The results showed that the PPF was affected by all types of peripheral stimuli. With noise, brushing and pinching stimuli, the PPF decreased to 58.04 11.96%, 58.22 8.21% and 51.15 6.63 % respectively comparing to the control. In formalin injection test, the PPF decreased to 60.08 8.46% in phase 1 (after 1-5 mins) and 58.49 2.36% in phase 2 (after 18-30mins). In laser stimulation test, the PPF decreased to 68.55 7.58% when the laser stimulation preceded paired-pulse stimulation with 100-200ms and 48.94 22.73% when the delay was 350-500ms. In sciatic nerve stimulation, the PPF decreased to 72.55 8.38% when the delay between laser stimulation and paired-pulse stimulation was 60ms. Present results showed that innocuous and noxious peripheral stimuli reduced the PPF. Thus it strongly indicates that the short term plasticity in the ACC is modulated by somatic afferent inputs. Supported by: Nation Science Council and Academia Sinica Citation: J.-J. Sun, S.-Y. Cheng, S.-L. Chen, S.-C. Chai, B.-C. Shyu. THE INFLUENCE OF PERIPHERAL STIMULATION ON THE PAIRED-PULSE FACILITATION IN THE ANTERIOR CINGULATE CORTEX OF THE RAT Program No. 754.5. 2002 Abstract Viewer/Itinerary Planner. Washington, DC: Society for Neuroscience, 2002. Online. Site Design and Programming © ScholarOne, Inc., 2002. All Rights Reserved. Patent Pending.