Acute marijuana effects on rCBF and cognition

O’Leary, Daniel S.; Block, Robert I.; Flaum, Michael; Schultz, Susan K.; Ponto, Laura L. Boles; Watkins, G. Leonard; Hurtig, Richard R.; Andreasen, N.C.; Hichwa, Richard D.

doi:10.1097/00001756-200011270-00047

Cited by 63 publications

(58 citation statements)

References 4 publications

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“…This regional profile of effects is largely in accordance with the distribution of CB1 cannabinoid receptors at which THC acts (Devane et al, 1988;Mechoulam et al, 1970;Glass et al, 1997;Herkenham et al, 1990Herkenham et al, , 1991a, and THC-induced alterations in activity in these areas have also been demonstrated in previous IEG and metabolic mapping studies performed in rodents (Bloom et al, 1997;ErdtmannVourliotis et al, 1999;Mailleux et al, 1994;Margulies and Hammer, 1991;McGregor et al, 1998;Whitlow et al, 2002). In addition, human imaging studies have consistently demonstrated marked alterations in activity in frontal brain regions following acute marijuana/THC intake or chronic marijuana use (Lundqvist et al, 2001;Mathew and Wilson, 1993;Mathew et al, 1997Mathew et al, , 2002O'Leary et al, 2000O'Leary et al, , 2002Volkow et al, 1996).…”

Section: Discussionsupporting

confidence: 72%

Acute Δ9-Tetrahydrocannabinol-Induced Deficits in Reversal Learning: Neural Correlates of Affective Inflexibility

Egerton

Brett

Pratt

2005

Neuropsychopharmacol

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Despite concerns surrounding the possible adverse effects of marijuana on complex cognitive function, the processes contributing to the observed cognitive deficits are unclear, as are the causal relationships between these impairments and marijuana exposure. In particular, marijuana-related deficits in cognitive flexibility may affect the social functioning of the individual and may contribute to continued marijuana use. We therefore examined the ability of rats to perform affective and attentional shifts following acute administration of D 9 -tetrahydrocannabinol (THC), the primary psychoactive marijuana constituent. Administration of 1 mg/kg THC produced marked impairments in the ability to reverse previously relevant associations between stimulus features and reward presentation, while the ability to transfer attentional set between dimensional stimulus properties was unaffected. Concurrent in situ hybridization analysis of regional c-fos and ngfi-b expression highlighted areas of the prefrontal cortex and striatum that were recruited in response to both THC administration and task performance. Furthermore, the alterations in mRNA expression in the orbitofrontal cortex and striatum were associated with the ability to perform the reversal discriminations. These findings suggest that marijuana use may produce inelasticity in updating affective associations between stimuli and reinforcement value, and that this effect may arise through dysregulation of orbitofrontal and striatal circuitry.

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Section: Discussionsupporting

confidence: 72%

Acute Δ9-Tetrahydrocannabinol-Induced Deficits in Reversal Learning: Neural Correlates of Affective Inflexibility

Egerton

Brett

Pratt

2005

Neuropsychopharmacol

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“…In general anesthesia, somatosensory and motor signals from large parts of the body are disturbed through the application of muscle relaxants while the patient may be in a state of partial awareness due to insufficient levels of anesthetic. The resulting state (partial awareness combined with abnormal somatosensory and motor signals) has been proposed as a main pathomechanism for awareness during general anesthesia (Blacher, 1975;Moermann et al, 1993;Sandin et al, 2000;Spitellie et al, 2002) and might also account for OBEs in these circumstances (Bü nning and Blanke, 2005). Thus, disturbed somatosensory and sensorimotor signals from large parts of the body in (1) tetraplegia with severe somatosensory loss (as in our patient), (2) during general anesthesia (Moermann et al, 1993), and (3) during sleep paralysis (Nelson et al, 2006;Girard et al, 2007;Cheyne and Girard, 2009, this issue) seem to disturb integration of multisensory body-related information in personal space due to interference with brainstem, spinal cord and peripheral nervous system signalling information from the somatosensory and motor systems.…”

Section: Discussionmentioning

confidence: 99%

“…Thus, cannabis consumption does not seem to be sufficient for the induction of repeated OBEs, yet this might be the case if additional brain damage exists. At present we do not know whether differences in the induction of OBEs due to cannabis consumption exist depending on whether brain damage occurs at cortical structures, peduncular, cerebellar, or spinal mechanisms as cannabis consumptions have been shown to interfere with brain processing at these various regions (Mathew et al, 1997;Volkow et al, 1996;O'Leary et al, 2000; for review see Bü nning and Blanke, 2005). Especially, we cannot exclude that additional white matter lesions in temporo-parietal areas might have been present.…”

Section: Discussionmentioning

confidence: 99%

Deficient mental own-body imagery in a neurological patient with out-of-body experiences due to cannabis use

Overney

Arzy

Blanke

2009

Cortex

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Mental imagery Body Drug use a b s t r a c tIn the present work, we report repeated out-of-body experiences (OBEs) in a patient with tetraplegia and severe somatosensory loss due to multiple sclerosis and predominant involvement of the cervical spinal cord. OBEs were experienced on a daily basis and induced by cannabis treatment that was started for severe spasticity with painful cramps and cloni.In order to investigate the link between OBEs and mental own-body imagery, the patient was asked to imagine himself in the position and visual perspective that is generally reported during OBEs, using front-and back-facing schematic human stimuli. Performance was measured before and after cannabis consumption. First, our data reveal that the patient was less accurate for back-facing than front-facing stimuli. This was found before and after cannabis consumption and is the opposite pattern to what is generally observed in healthy participants and in our control subjects (who did not use cannabis). We refer to this as lesion effect and argue that this relative facilitation for stimuli reflecting the position and visual perspective that is generally reported during OBEs might be due to recurrent and spontaneous own-body transformations during the patient's frequent OBEs. Secondly, we found a cannabis effect, namely a performance improvement in the back-facing condition while performance in the front-facing condition remained unchanged, after cannabis administration. We argue that cannabis administration may interfere with own-body imagery when reflecting the actual body position and only when associated with brain damage. Based on these data we propose an extended neurological model for own-body illusions including multisensory and sensorimotor mechanisms, cannabis consumption, and cortical and subcortical processing.

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“…Positron emission tomography (PET) imaging has given investigators further clues for the site of action of smoked marijuana on brain function. O'Leary et al demonstrated substantial reduction in blood flow to the temporal lobe when volunteers showed impaired performance of auditory attention tasks [21]. Marijuana smoking has also been shown to increase blood flow in the frontal lobes and lateral cerebellum at rest [22,23].…”

Section: Introductionmentioning

confidence: 99%

Medical Marijuana and Driving: a Review

et al. 2014

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Medical marijuana remains a highly debated treatment regimen despite removal of state penalties against care providers prescribing the drug and patients treated with the drug in many areas of the USA. The utility of marijuana in specific medical conditions has been studied at length, but its effects on driving performance and risk of motor vehicle collision remain unclear. As with other medications that affect psychomotor function, the healthcare provider should be informed of the potential risks of driver safety prior to prescribing this psychotropic drug to give appropriate anticipatory guidance for appropriate use. The goal of this narrative review is to assess the current literature regarding marijuana as it relates to driving performance and traffic safety. With a foundation in the pharmacology of cannabinoids, we consider the limitations of testing cannabinoid and metabolite concentration. In addition, we will review studies on driving performance and epidemiological studies implicating marijuana in motor vehicle collisions. The increasing prevalence of medical marijuana laws in the USA suggests that clinicians should be aware of marijuana's influence on public safety. Patients should abstain from driving for 8 h if they achieve a subjective "high" from self-treatment with smoked marijuana and should be aware of the cumulative effects of alcohol and other psychoactive xenobiotics.

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Acute marijuana effects on rCBF and cognition

Cited by 63 publications

References 4 publications

Acute Δ9-Tetrahydrocannabinol-Induced Deficits in Reversal Learning: Neural Correlates of Affective Inflexibility

Acute Δ9-Tetrahydrocannabinol-Induced Deficits in Reversal Learning: Neural Correlates of Affective Inflexibility

Deficient mental own-body imagery in a neurological patient with out-of-body experiences due to cannabis use

Medical Marijuana and Driving: a Review

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