Impaired induction of long-term potentiation-like plasticity in patients with high-functioning autism and Asperger syndrome
Version of Record online: 15 NOV 2012
© The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press
Developmental Medicine & Child Neurology
Volume 55, Issue 1, pages 83–89, January 2013
How to Cite
JUNG, N. H., JANZARIK, W. G., DELVENDAHL, I., MÜNCHAU, A., BISCALDI, M., MAINBERGER, F., BÄUMER, T., RAUH, R. and MALL, V. (2013), Impaired induction of long-term potentiation-like plasticity in patients with high-functioning autism and Asperger syndrome. Developmental Medicine & Child Neurology, 55: 83–89. doi: 10.1111/dmcn.12012
- Issue online: 13 DEC 2012
- Version of Record online: 15 NOV 2012
- PUBLICATION DATA Accepted for publication 10th August 2012. Published online.
Aim We aimed to investigate the induction of long-term potentiation (LTP)-like plasticity by paired associative stimulation (PAS) in patients with high-functioning autism and Asperger syndrome (HFA/AS).
Method PAS with an interstimulus interval between electrical and transcranial magnetic stimulation of 25 ms (PAS25) was performed in patients with HFA/AS (n=9; eight males, one female; mean age 17y 11mo, SD 4y 5mo) and in typically developing age-matched volunteers (n=9; five males, four females; mean age 22y 4mo, SD 5y 2mo). The amplitude of motor-evoked potentials was measured before PAS25, immediately after stimulation, and 30 minutes and 60 minutes later. A PAS protocol adapted to individual N20 latency (PASN20+2) was performed in six additional patients with HFA/AS. Short-interval intracortical inhibition was measured using paired-pulse stimulation.
Results In contrast to the typically developing participants, the patients with HFA/AS did not show a significant increase in motor-evoked potentials after PAS25. This finding could also be demonstrated after adaptation for N20 latency. Short-interval intracortical inhibition of patients with HFA/AS was normal compared with the comparison group and did not correlate with PAS effect.
Interpretation Our results show a significant impairment of LTP-like plasticity induced by PAS in individuals with HFA/AS compared with typically developing participants. This finding is in accordance with results from animal studies as well as human studies. Impaired LTP-like plasticity in patients with HFA/AS points towards reduced excitatory synaptic connectivity and deficits in sensory-motor integration in these patients.