Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
PLoS One. 2012;7(7):e39955. doi: 10.1371/journal.pone.0039955. Epub 2012 Jul 5.
Periodic auditory click stimulation has been reported to elicit an auditory steady state response (ASSR). The ASSR has been suggested to reflect the efficiency of γ-amino butyric acid (GABA) inhibitory interneuronal activity. Although a potential role for GABAergic dysfunction has been previously proposed, the role of neural synchronization in the ASSR in people with bipolar disorder (BD) has received little attention. In the current study, we investigated ASSRs to 20 Hz, 30 Hz, 40 Hz and 80 Hz click trains in BD patients. A total of 14 (4 males) BD patients and 25 (10 males) healthy controls participated in this study. ASSRs were obtained using whole-head 306-channel magnetoencephalography to calculate, ASSR power values and phase locking factors (PLF). BD patients exhibited significantly reduced mean ASSR power and PLF values bilaterally at frequencies of 30, 40, and 80 Hz (p<0.05 for these frequencies). At 20 Hz, bipolar patients showed no significant reduction in mean ASSR power and PLF values. There was a significant negative correlation between 80 Hz-ASSR-power values obtained from the right hemisphere and scores on the Hamilton Depression Rating Scale (rho = -0.86, p = 0.0003). The current study showed reduced low and high gamma band ASSR power and PLF bilaterally with no significant beta band ASSR reduction in BD patients. BD patients are characterized by deficits in gamma band oscillations, which may be associated with GABA inhibitory interneuronal activity dysfunction.
周期性听觉点击刺激已被报道可引发听觉稳态反应（ASSR）。ASSR 被认为反映了γ-氨基丁酸（GABA）抑制性中间神经元活动的效率。尽管先前已经提出 GABA 能功能障碍的潜在作用，但在双相障碍（BD）患者中，ASSR 中的神经同步作用尚未得到充分关注。在当前的研究中，我们研究了 BD 患者对 20 Hz、30 Hz、40 Hz 和 80 Hz 点击序列的 ASSR。共有 14 名（4 名男性）BD 患者和 25 名（10 名男性）健康对照者参加了这项研究。使用全头 306 通道脑磁图来计算 ASSR 功率值和相位锁定因子（PLF），以获得 ASSRs。BD 患者在 30、40 和 80 Hz 频率下双侧的平均 ASSR 功率和 PLF 值显著降低（这些频率的 p<0.05）。在 20 Hz 时，双相患者的平均 ASSR 功率和 PLF 值没有明显降低。右侧半球 80 Hz-ASSR 功率值与汉密尔顿抑郁评定量表（HDRS）评分之间存在显著负相关（rho = -0.86，p = 0.0003）。当前的研究表明，BD 患者双侧低频和高频γ频段 ASSR 功率和 PLF 降低，而β频段 ASSR 无明显降低。BD 患者的特征是γ频段振荡缺陷，这可能与 GABA 抑制性中间神经元活动功能障碍有关。
