High‐power gamma‐related delta phase alteration in schizophrenia patients at rest

Abstract

Aim Information processing is supported by the cortico‐cortical transmission of neural oscillations across brain regions. Recent studies have demonstrated that the rhythmic firing of neural populations is not random but is governed by interactions with other frequency bands. Specifically, the amplitude of gamma‐band oscillations is associated with the phase of lower frequency oscillations in support of short and long‐range communications among networks. This cross‐frequency relation is thought to reflect the temporal coordination of neural communication. While schizophrenia patients show abnormal oscillatory responses across multiple frequencies at rest, it is unclear whether the functional relationships among frequency bands are intact. This study aimed to characterize the lower frequency (delta/theta, 1–8 Hz) phase and the amplitude of gamma oscillations in healthy subjects and schizophrenia patients at rest. Methods Low frequency‐phase (delta‐ and theta‐ band) angles and gamma‐band amplitude relationships were assessed in 142 schizophrenia patients and 128 healthy subjects. Results Significant low‐frequency phase alteration related to high‐power gamma was detected across broadly distributed scalp regions in both healthy subjects and patients. In patients, delta phase synchronization related to high‐power gamma was significantly decreased at the frontocentral, right middle temporal, and left temporoparietal electrodes but significantly increased at the left parietal electrode. Conclusions High‐power gamma‐related delta phase alteration may reflect a core pathophysiologic abnormality in schizophrenia. Data‐driven measures of functional relationships among frequency bands may prove useful in the development of novel therapeutics. Future studies are needed to determine whether these alterations are specific to schizophrenia or appear in other neuropsychiatric patient populations.

Characterizing endogenous delta oscillations in human MEG

“…The outlined procedures can be used to derive a spatio-spectral filter (or localizer), serving to extract the signal of interest, for instance when interested in mechanisms of synchronization to external rhythms 113 , or memory consolidation, functionally linked to delta oscillations. This approach can also be applied in the assessment of clinical populations that show characteristic alterations in delta oscillations 9 , 114 , 115 , for instance in schizophrenia, where increased delta oscillatory power is observed over frontal regions. The approach proposed here will hopefully help to promote a more unified reporting of the physiological characteristics of delta oscillations relevant to a particular task, or pathology, to eventually enable meta-analytic approaches as currently available for alpha oscillations 116 .…”

40 Hz Blue LED Relieves the Gamma Oscillations Changes Caused by Traumatic Brain Injury in Rat

“…Gamma oscillations play a pivotal role in multiple cognitive functions. They enable coordinated activity and communication of local assemblies, while abnormalities in gamma oscillations exist in different neurological and psychiatric diseases (25,26). Increasing evidence shows that guiding or driving gamma oscillations are being investigated as a potential treatment paradigm for memory deficits due to Alzheimer's disease and other memory impairments (27,28) may induce an overall neuroprotective response that recruits both neurons and microglia (11).…”

Abnormal phase entrainment of low- and high-gamma-band auditory steady-state responses in schizophrenia

“…Gamma-band (30–100 Hz) oscillatory deficits have attracted considerable attention as a promising neurophysiological endophenotype of schizophrenia (SZ) due to their well-established association with various psychiatric symptoms and specific cognitive deficits observed in SZ ( Uhlhaas and Singer, 2010 ; Hirano and Uhlhaas, 2021 ; Koshiyama et al, 2022 ; Onitsuka et al, 2022a , b , c ; Sohal, 2022 ). Gamma-band oscillations are responsible for the temporal coordination of narrowly localized neural circuits throughout the brain ( von Stein and Sarnthein, 2000 ; Fries et al, 2007 ; Buzsáki and Wang, 2012 ; Arnulfo et al, 2015 ; Buzsáki and Schomburg, 2015 ).…”