Neurophysiological profile of acoustic startle response : candidate endophenotype of Autism spectrum disorders

Abstract

The acoustic startle response (ASR) and its modulations are useful neurophysiological measurements in translational research. In particular, prepulse inhibition (PPI) of ASR is considered a candidate endophenotype of psychiatric diseases. However, findings from previous studies of PPI in autism spectrum disorders (ASD) have been inconsistent. Recently, we reported larger ASR magnitude to weak stimuli and prolonged peak startle latency in children with ASD. An atypical profile of ASR in ASD might therefore explain the inconsistent results in previous PPI studies. In addition, the relationship of ASR modulations to clinical characteristics of ASD is not known well. Thus, we investigated PPI with several prepulse intensities and its relationship to autistic traits and other emotional - behavioral problems in children with ASD and with typical development. Although, no significant difference for PPI or habituation was observed in ASD children compared to controls, habituation and PPI at relatively weak prepulse were negatively related to several autistic traits subscales and other emotional - behavioral problems, when considering all children. The comprehensive investigation of ASR and its modulation, including the magnitude of startle responses to weak stimuli peak startle latency, habituation, and PPI, might increase understanding of the neurophysiological impairments underlying ASD and other mental health problems in children.