Research suggest that in autism spectrum disorder (ASD) a disturbance in the coordinated interactions of neurons within local networks gives rise to abnormal patterns of brainwave activity in the gamma bandwidth. Low frequency transcranial magnetic stimulation (TMS) over the dorsolateral prefrontal cortex (DLPFC) has been proven to normalize gamma oscillation abnormalities, executive functions, and repetitive behaviors in high functioning ASD individuals. In this study, gamma frequency oscillations in response to a visual classification task (Kanizsa figures) were analyzed and compared in 19 ASD (ADI-R diagnosed, 14.2 ± 3.61 years old, 5 girls) and 19 (14.8 ± 3.67 years old, 5 girls) age/gender matched neurotypical individuals. The ASD group was treated with low frequency TMS (1.0 Hz, 90% motor threshold, 18 weekly sessions) targeting the DLPFC. In autistic subjects, as compared to neurotypicals, significant differences in event-related gamma oscillations were evident in amplitude (higher) pre-TMS. In addition, recordings after TMS treatment in our autistic subjects revealed a significant reduction in the time period to reach peak amplitude and an increase in the decay phase (settling time). The use of a novel metric for gamma oscillations. i.e., envelope analysis, and measurements of its ringing decay allowed us to characterize the impedance of the originating neuronal circuit. The ringing decay or dampening of gamma oscillations is dependent on the inhibitory tone generated by networks of interneurons. The results suggest that the ringing decay of gamma oscillations may provide a biomarker reflective of the excitatory/inhibitory balance of the cortex and a putative outcome measure for interventions in autism.

研究表明，在自闭症谱系障碍 (ASD) 中，局部网络内神经元协调相互作用的干扰会导致伽马带宽中脑电波活动的异常模式。背外侧前额叶皮层 (DLPFC) 的低频经颅磁刺激 (TMS) 已被证明可以使高功能 ASD 个体的伽马振荡异常、执行功能和重复行为正常化。在这项研究中，在 19 名 ASD（诊断为 ADI-R，14.2 ± 3.61 岁，5 名女孩）和 19 名（14.8 ± 3.67 岁，5 名女孩）中分析和比较了响应视觉分类任务（Kanizsa 数字）的伽马频率振荡女孩）年龄/性别匹配的神经典型个体。ASD 组接受了针对 DLPFC 的低频 TMS（1.0 Hz，90% 运动阈值，每周 18 次）治疗。在自闭症受试者中，与神经典型患者相比，事件相关伽马振荡的显着差异在振幅（更高）前 TMS 中很明显。此外，我们的自闭症受试者在 TMS 治疗后的录音显示，达到峰值振幅的时间显着减少，衰减阶段（稳定时间）增加。伽马振荡的新度量的使用。即，包络分析及其振铃衰减的测量使我们能够表征原始神经元电路的阻抗。伽马振荡的振铃衰减或衰减取决于中间神经元网络产生的抑制音调。