Prepulse inhibition of auditory change-related cortical responses

• Main Authors: Inui Koji, Tsuruhara Aki, Kodaira Minori, Motomura Eishi, Tanii Hisashi, Nishihara Makoto, Keceli Sumru, Kakigi Ryusuke
• Format: Article
• Language: English
• Published: BMC 2012-10-01
• Series: BMC Neuroscience
• Online Access: http://www.biomedcentral.com/1471-2202/13/135

<p>Abstract</p> <p>Background</p> <p>Prepulse inhibition (PPI) of the startle response is an important tool to investigate the biology of schizophrenia. PPI is usually observed by use of a startle reflex such as blinking following an intense sound. A similar phenomenon has not been reported for cortical responses.</p> <p>Results</p> <p>In 12 healthy subjects, change-related cortical activity in response to an abrupt increase of sound pressure by 5 dB above the background of 65 dB SPL (test stimulus) was measured using magnetoencephalography. The test stimulus evoked a clear cortical response peaking at around 130 ms (Change-N1m). In Experiment 1, effects of the intensity of a prepulse (0.5 ~ 5 dB) on the test response were examined using a paired stimulation paradigm. In Experiment 2, effects of the interval between the prepulse and test stimulus were examined using interstimulus intervals (ISIs) of 50 ~ 350 ms. When the test stimulus was preceded by the prepulse, the Change-N1m was more strongly inhibited by a stronger prepulse (Experiment 1) and a shorter ISI prepulse (Experiment 2). In addition, the amplitude of the test Change-N1m correlated positively with both the amplitude of the prepulse-evoked response and the degree of inhibition, suggesting that subjects who are more sensitive to the auditory change are more strongly inhibited by the prepulse.</p> <p>Conclusions</p> <p>Since Change-N1m is easy to measure and control, it would be a valuable tool to investigate mechanisms of sensory gating or the biology of certain mental diseases such as schizophrenia.</p>