We investigated whether the gray matter volume of primary auditory cortex (Heschl’s gyrus [HG]) was associated with abnormal patterns of auditory γ activity in schizophrenia, namely impaired γ synchronization in the 40-Hz auditory steady-state response (ASSR) and increased spontaneous broadband γ power. (The γ data were previously reported in Hirano et al, JAMA Psychiatry, 2015;72:813-821). Participants were 24 healthy controls (HC) and 23 individuals with chronic schizophrenia (SZ). The ASSR was obtained from the electroencephalogram to click train stimulation at 20, 30, and 40 Hz rates. Dipole source localization of the ASSR was used to provide a spatial filter of auditory cortex activity, from which ASSR evoked power and phase locking factor (PLF), and induced γ power were computed. HG gray matter volume was derived from structural magnetic resonance imaging at 3 T with manually traced regions of interest. As expected, HG gray matter volume was reduced in SZ compared with HC. In SZ, left hemisphere ASSR PLF and induced γ power during the 40-Hz stimulation condition were positively and negatively correlated with left HG gray matter volume, respectively. These results provide evidence that cortical gray matter structure, possibly resulting from reduced synaptic connectivity at the microcircuit level, is related to impaired γ synchronization and increased spontaneous γ activity in schizophrenia.

中文翻译：

---

精神分裂症的听觉皮层体积和伽马振荡异常

我们研究了初级听觉皮层（Heschl 回 [HG]）的灰质体积是否与精神分裂症中听觉 γ 活动的异常模式有关，即 40-Hz 听觉稳态反应（ASSR）中的 γ 同步受损和自发性增加宽带γ功率。（先前在 Hirano 等人，JAMA Psychiatry，2015；72：813-821 中报道了 γ 数据）。参与者是 24 名健康对照 (HC) 和 23 名患有慢性精神分裂症 (SZ) 的人。ASSR 是从脑电图获得的，以 20、30 和 40 Hz 的速率点击列车刺激。ASSR 的偶极源定位用于提供听觉皮层活动的空间滤波器，从中 ASSR 诱发功率和锁相因子 (PLF)，并计算诱导 γ 功率。HG 灰质体积来自 3 T 的结构磁共振成像，手动追踪感兴趣区域。正如预期的那样，与 HC 相比，SZ 中的 HG 灰质体积减少。在 SZ 中，40 Hz 刺激条件下的左半球 ASSR PLF 和诱导 γ 功率分别与左侧 HG 灰质体积呈正相关和负相关。这些结果提供了证据，表明皮质灰质结构可能是由微电路水平的突触连接减少引起的，与精神分裂症中γ同步受损和自发γ活动增加有关。在 40 Hz 刺激条件下，左半球 ASSR PLF 和诱导 γ 功率分别与左 HG 灰质体积呈正相关和负相关。这些结果提供了证据，表明皮质灰质结构可能是由微电路水平的突触连接减少引起的，与精神分裂症中γ同步受损和自发γ活动增加有关。在 40 Hz 刺激条件下，左半球 ASSR PLF 和诱导 γ 功率分别与左 HG 灰质体积呈正相关和负相关。这些结果提供了证据，表明皮质灰质结构可能是由微电路水平的突触连接减少引起的，与精神分裂症中γ同步受损和自发γ活动增加有关。