Transcranial photobiomodulation (tPBM) is the application of low levels of red or near-infrared (NIR) light to stimulate neural tissues. Here, we administer tPBM in the form of NIR light (810 nm wavelength) pulsed at 40 Hz to the default mode network (DMN), and examine its effects on human neural oscillations, in a randomized, sham-controlled, double-blinded trial. Using electroencephalography (EEG), we found that a single session of tPBM significantly increases the power of the higher oscillatory frequencies of alpha, beta and gamma and reduces the power of the slower frequencies of delta and theta in subjects in resting state. Furthermore, the analysis of network properties using inter-regional synchrony via weighted phase lag index (wPLI) and graph theory measures, indicate the effect of tPBM on the integration and segregation of brain networks. These changes were significantly different when compared to sham stimulation. Our preliminary findings demonstrate for the first time that tPBM can be used to non-invasively modulate neural oscillations, and encourage further confirmatory clinical investigations.

Previous studies have demonstrated that alcohol consumption impairs neuroplasticity in the motor cortex. However, it is unknown whether alcohol produces a similar impairment of neuroplasticity in the dorsolateral prefrontal cortex (DLPFC), a brain region that plays an important role in cognitive functioning. The aim of the current study was to evaluate the effect of alcohol intoxication on neuroplasticity in the DLPFC. Paired associative stimulation (PAS) combined with electroencephalography (EEG) was used for the induction and measurement of associative LTP-like neuroplasticity in the DLPFC. Fifteen healthy subjects were administered PAS to the DLPFC following consumption of an alcohol (1.5 g/l of body water) or placebo beverage in a within-subject cross-over design. PAS induced neuroplasticity was indexed up to 60 minutes following PAS. Additionally, the effect of alcohol on PAS-induced potentiation of theta-gamma coupling (an index associated with learning and memory) was examined prior to and following PAS. Alcohol consumption resulted in a significant impairment of mean (t = 2.456, df = 13, p = 0.029) and maximum potentiation (t = −2.945, df = 13, p = 0.011) compared to the placebo beverage in the DLPFC and globally. Alcohol also suppressed the potentiation of theta-gamma coupling by PAS. Findings from the present study provide a potential neurophysiological mechanism for impairment of cognitive functioning by alcohol.

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IntroductionAs a primary point of contact within the health care system, family physicians are able to play a vital role in identifying individuals with substance use disorders and connecting them to the appropriate treatment. However, there is very little data available on whether family physicians are actively screening for and treating substance use disorders. The objective of the current survey was to assess whether family physicians in Ontario are screening for alcohol, opioid and tobacco use disorders, using validated tools and providing treatment.MethodsAn online survey consisting of a series of 38 primarily close-ended questions was circulated to family physicians in Ontario. Rates of screening for alcohol, opioid and tobacco dependence, use of validated tools for screening, providing treatment for dependent individuals and the current barriers to the prescription of pharmacotherapies for these drug dependences were assessed.ResultsThe use of validated screening tools was limited for all three substances. Screening by family physicians for the substance use disorders among adolescents was much lower than screening among adults. Pharmacotherapy was more commonly used as an intervention for tobacco dependence than for alcohol and opioid dependence. This was explained by the lack of knowledge among family physicians on the pharmacotherapies for alcohol and opioid dependence.ConclusionsFindings from the current study suggest there is a need for family physicians to integrate screening for substance use disorders using validated tools into their standard medical practice. Furthermore, there is a need for increased knowledge on pharmacotherapies for alcohol and opioid use disorders. It is important to note that the low response rate is a major limitation to this study. One possible reason for this low response rate may be a lack of interest and awareness among family physicians on the importance of screening and treatment of substance use disorders in Ontario.