EVENT-RELATED POTENTIALS OF THE RAT DURING ACTIVE AND PASSIVE AUDITORY ODDBALL PARADIGMS

Event-related potentials (ERPs) of the rat were recorded at the fronta l, temporal and parietal areas on the skull during active and passive auditory oddball paradigms, and consisted of P1 (12.7-37.7 ms), N1 (40 .0-80.6 ms), P2 (91.7-202.7 ms), N2 (183.7-246.7 ms) and P3 (265.7-462 .7 ms) components. Topography and relationship to the paradigm and sti mulus types were examined, and unique features were found for each com ponent. P1, N1 and N2 were prominent frontally. However, P2 showed max imum amplitude at the parietal area. N2 and P3 were consistently prese nt only for rare stimuli. During the passive paradigm P3 had a tendenc y to be greater at the parietal area, but during the active paradigm i t had a longer latency and a larger amplitude than during the passive paradigm. No significant difference between the recording sites was ob served for P3 latency and amplitude during the active paradigm. The re lationship to the paradigm and stimulus types indicates that the rat P 3 corresponds to that of the human. There are differences, however, in surface distribution of the ERP components between the rat and the hu man. The topographical characteristics of the rat ERP, which are possi bly due to differences in brain architecture and function, should be t aken into consideration when the rat is used for ERP research. (C) 199 7 Elsevier Science Ireland Ltd.