bioRxiv : the preprint server for biology
August 22, 2025
Jose A Cortes-Briones, Juan Urrutia-Gandolfo, Pablo A Estevez et al.
preprint
The balance between excitatory and inhibitory (E/I) activity is critical for brain function, and its disruption is implicated in neuropsychiatric disorders. Electrophysiological signals can be decomposed into periodic (oscillatory) and aperiodic components. In the power spectrum, the periodic component appears as narrowband peaks, while the aperiodic component underlies its characteristic 1 / f...
Journal of Psychopharmacology
June 30, 2023
Jordan Sloshower, Hamideh Safi-Aghdam, Surbhi Pathania et al.
47 citations
Background: Evidence suggests that serotonergic psychedelics (e.g. psilocybin), have rapid-acting and long-lasting antidepressant effects after a single dose. However, the mechanism underlying these effects remain unclear. One proposed mechanism is that these drugs promote neuroplasticity. However, this has not been conclusively demonstrated in humans. Aims: We hypothesized that relative to...
Journal of Psychopharmacology
March 20, 2023
Jordan Sloshower, Hamideh Safi-Aghdam, Surbhi Pathania et al.
153 citations
Background: Several early phase studies have demonstrated that psilocybin-assisted therapy has rapid-acting and persisting antidepressant effects from just one or two doses. However, methodological limitations (e.g., placebo-control, blinding) limit interpretability of the existing literature. Methods: In an exploratory placebo-controlled, within-subject, fixed-order study, individuals with...
Clinical EEG and Neuroscience
November 25, 2022
Shariful A. Syed, Ashley M. Schnakenberg Martin, Jose A Cortes-Briones et al.
Disruptions in neural oscillations are believed to be one critical mechanism by which cannabinoids, such as delta-9-tetrahyrdrocannabinol (THC; the primary psychoactive constituent of cannabis), perturbs brain function. Here we briefly review the role of synchronized neural activity, particularly in the gamma (30–80 Hz) and theta (4–7 Hz) frequency range, in sensation, perception, and...
Psychopharmacology
May 2022
Anahita Bassir Nia, Maria J Orejarena, Leigh Flynn et al.
Cannabis is the most common illicit drug used in the USA and its use has been rising over the past decade, while the historical gap in rates of use between men and women has been decreasing. Sex differences in the effects of cannabinoids have been reported in animal models, but human studies are sparse and inconsistent. We investigated the sex differences in the acute subjective,...
Journal of Psychopharmacology
December 2018
Douglas L Boggs, Jose A Cortes-Briones, Toral Surti et al.
Binding studies have demonstrated that levels of the cannabinoid receptor type-1 are highest in the basal ganglia and cerebellum, two areas critical for motor control. However, no studies have systematically examined the dose-related effects of intravenous delta-9-tetrahydrocannabinol, the primary cannabinoid receptor type-1 partial agonist in cannabis, on broad domains of psychomotor function...
Neuropharmacology
June 2018
Patrick D. Skosnik, Mihály Hajós, Jose A Cortes-Briones et al.
Cannabis use has been associated with altered sensory gating and neural oscillations. However, it is unclear which constituent in cannabis is responsible for these effects, or whether these are cannabinoid receptor 1 (CB1R) mediated. Therefore, the present study in humans and rats examined whether cannabinoid administration would disrupt sensory gating and evoked oscillations utilizing...
Progress in Neuro-Psychopharmacology and Biological Psychiatry
October 3, 2017
Mohini Ranganathan, Rajiv Radhakrishnan, Peter H. Addy et al.
Cannabis and agonists of the brain cannabinoid receptor (CB1R) produce acute memory impairments in humans. However, the extent to which cannabinoids impair the component processes of encoding and retrieval has not been established in humans. The objective of this analysis was to determine whether the administration of Δ9-Tetrahydrocannabinol (THC), the principal psychoactive constituent of...
Neuropsychopharmacology
August 2015
Jose A Cortes-Briones, Patrick D. Skosnik, Daniel H. Mathalon et al.
Gamma (γ)-band oscillations play a key role in perception, associative learning, and conscious awareness and have been shown to be disrupted by cannabinoids in animal studies. The goal of this study was to determine whether cannabinoids disrupt γ-oscillations in humans and whether these effects relate to their psychosis-relevant behavioral effects. The acute, dose-related effects of...
Neuropsychopharmacology
December 2014
Patrick D. Skosnik, Giri P Krishnan, Deepak C D'Souza et al.
Previous work in animals and humans has shown that exogenous cannabinoids disrupt time-locked, evoked gamma oscillations (30-80 Hz). However, no studies to date have examined the effect of cannabis on non-time-locked, induced gamma oscillations during more complex Gestalt perception. The current study therefore utilized electroencephalography (EEG) to examine gamma oscillations during coherent...
Journal of Psychopharmacology
November 2014
H Cheng, Patrick D. Skosnik, Ben J Pruce et al.
Chronic cannabis use can cause cognitive, perceptual and personality alterations, which are believed to be associated with regional brain changes and possible changes in connectivity between functional regions. This study aims to identify the changes from resting state functional magnetic resonance imaging scans. A two-level multi-voxel pattern analysis was proposed to classify male cannabis...
Journal of Psychopharmacology
June 2013
Daniel J Fridberg, Patrick D. Skosnik, William P Hetrick et al.
Chronic cannabis use is associated with residual negative effects on measures of executive functioning. However, little previous work has focused specifically on executive processes involved in performance monitoring in frequent cannabis users. The present study investigated event-related potential (ERP) correlates of performance monitoring in chronic cannabis users. The error-related...
Psychopharmacology
November 24, 2012
Richard A Sewell, Ashley Schnakenberg, Jacqueline Elander et al.
Cannabinoids have been shown to alter time perception, but existing literature has several limitations. Few studies have included both time estimation and production tasks, few control for subvocal counting, most had small sample sizes, some did not record subjects’ cannabis use, many tested only one dose, and used either oral or inhaled administration of Δ9-tetrahydrocannabinol (THC), leading...
Biological Psychiatry
November 15, 2012
Mohini Ranganathan, Ashley Schnakenberg, Patrick D. Skosnik et al.
125 citations
Salvia divinorum (Salvia) is an increasingly popular recreational drug amongst adolescents and young adults. Its primary active ingredient, Salvinorin A (SA)-a highly selective agonist at the κ opiate receptor-is believed to be one of the most potent naturally occurring hallucinogens. However, there is little experimental data on the effects of SA in humans. In a 3-day, double-blind,...
Neuropsychopharmacology
September 2012
Patrick D. Skosnik, Deepak C D'Souza, Adam B. Steinmetz et al.
Animal and cellular work has shown that central cannabinoid-1 receptors modulate neural oscillations in the gamma range (40 Hz), which may be important for normal perceptual and cognitive processes. In order to assess the effect of cannabinoids on broadband-frequency neural oscillations in humans, the current study examined the effect of chronic cannabis use on auditory steady-state responses...
Neuropsychopharmacology
June 2012
Deepak Cyril D'Souza, Daniel J Fridberg, Patrick D. Skosnik et al.
Cannabinoids induce a host of perceptual alterations and cognitive deficits in humans. However, the neural correlates of these deficits have remained elusive. The current study examined the acute, dose-related effects of delta-9-tetrahydrocannabinol (Δ⁹-THC) on psychophysiological indices of information processing in humans. Healthy subjects (n=26) completed three test days during which they...
Brain Connectivity
2011
Dae-Jin Kim, Patrick D. Skosnik, Hu Cheng et al.
Endocannabinoid receptors modulate synaptic plasticity in the brain and may therefore impact cortical connectivity not only during development but also in response to substance abuse in later life. Such alterations may not be evident in volumetric measures utilized in brain imaging, but could affect the local and global organization of brain networks. To test this hypothesis, we used a novel...
Behavioral Neuroscience
August 1, 2009
Chad R. Edwards, Patrick D. Skosnik, Adam B. Steinmetz et al.
Central cannabinoid receptors are thought to mediate neural oscillations and are localized to brain regions implicated in auditory P50 sensory gating, including the hippocampus and neocortex. The current study therefore examined if neural oscillations evoked by the paired clicks (S1, S2) are associated with impaired P50 gating reported in cannabis users. Seventeen heavy cannabis users and 16...
Critical reviews in neurobiology
2007
Chad R. Edwards, Patrick D. Skosnik
Delta-9-tetrahydrocannabinol (THC) is the primary psycho-active ingredient in Cannabis spp., the most widely used illicit drug in the United States. THC is an exogenous agonist of the central cannabinoid receptor (CB1), one of the most abundant G-coupled receptors in the mammalian brain. Although CB1 receptors are distributed throughout the brain, they are found at very high levels in the...
American Journal of Psychiatry
October 2006
Patrick D. Skosnik, Giri P Krishnan, Erin E Aydt et al.
Cannabis use may produce neurophysiological disturbances similar to those observed in schizophrenia, particularly in relation to altered neural synchronization. Therefore, the current experiment examined the effect of cannabis use on EEG neural synchronization using the auditory steady-state evoked potential. Auditory steady-state evoked potentials were assessed using varying rates of...
Clinical Neurophysiology
January 2006
Patrick D. Skosnik, Giri P Krishnan, Jenifer L Vohs et al.
Cannabis use often induces subjective distortions of perception. However, little work has been done examining the electroencephalographic (EEG) correlates of early sensory processing in cannabis users. The present study therefore examined visual function in cannabis users as assessed via the steady state visual evoked potential. (SSVEP). SSVEPs were examined in current cannabis users (n = 17;...