Recent research has suggested that marijuana use is associated with volumetric and shape differences in subcortical structures, including the nucleus accumbens and amygdala, in a dose-dependent fashion. Replication of such results in well controlled studies is essential to clarify the effects of marijuana. To that end, this retrospective study examined brain morphology in a sample of adult daily marijuana users ( n = 29) versus nonusers ( n = 29) and a sample of adolescent daily users ( n = 50) versus nonusers ( n = 50). Groups were matched on a critical confounding variable, alcohol use, to a far greater degree than in previously published studies. We acquired high-resolution MRI scans, and investigated group differences in gray matter using voxel-based morphometry, surface-based morphometry, and shape analysis in structures suggested to be associated with marijuana use, as follows: the nucleus accumbens, amygdala, hippocampus, and cerebellum. No statistically significant differences were found between da...

Labilization is a boundary condition to memory retrieval-induced reconsolidation. Evidence suggests that GluN2B and GluN2A-containing NMDA and cannabinoid type-1 (CB1) receptors located in the dorsal hippocampus (DH) may contribute to these processes. D...

Chronic Δ9-tetrahydrocannabinol (Δ9-THC) administration produces tolerance to cannabinoid effects, but alterations in signal transduction that mediate these changes are not yet known. The present study uses in vitro autoradiography of agonist-stimulated [35S]GTPγS binding to localize cannabinoid receptor-activated G-proteins after chronic Δ9-THC treatment. Cannabinoid (WIN 55212-2)-stimulated [35S]GTPγS binding was performed in brain sections from rats treated chronically with 10 mg/kg Δ9-THC for 21 d. Control animals received saline or an acute injection of Δ9-THC. Acute Δ9-THC treatment had no effect on basal or WIN 55212-2-stimulated [35S]GTPγS binding. After chronic Δ9-THC treatment, net WIN 55212-2-stimulated [35S]GTPγS binding was reduced significantly (up to 70%) in most brain regions, including the hippocampus, caudate-putamen, perirhinal and entorhinal cortex, globus pallidus, substantia nigra, and cerebellum. In contrast, chronic Δ9-THC treatment had no effect on GABAB-stimulated [35S]GTPγS bindi...

Despite increased prevalence of maternal cannabis use, little is understood regarding potential long-term effects of prenatal cannabis exposure (PCE) on neurodevelopmental outcomes. While neurodevelopmental cannabis exposure increases the risk of developing affective/mood disorders in adulthood, the precise neuropathophysiological mechanisms in male and female offspring are largely unknown. Given the interconnectivity of the endocannabinoid system and the brain's fatty acid pathways, we hypothesized that prenatal exposure to Δ9-tetrahydrocannabinol (THC) may dysregulate fetal neurodevelopment through alterations of fatty-acid dependent synaptic and neuronal function in the mesolimbic system. To investigate this, pregnant Wistar rats were exposed to vehicle or THC (3mg/kg) from gestational day (GD) 7 until GD22. Anxiety-like, depressive-like, and reward-seeking behaviour, electrophysiology, and molecular assays were performed on adult male/female offspring. Imaging of fatty acids using matrix-assisted laser...

Lesion to the immature peripheral nervous system, such as the transection of a peripheral nerve, results in extensive degeneration of motoneurons and dorsal root ganglia (DRG) sensory neurons, mostly by apoptotic events. In turn, the axotomy of the scia...

As it is the case worldwide, marijuana (cannabis) use in the United States and Canada is highly prevalent and societal views of its use are changing rapidly, as are the policies that govern the legality of its recreational and medical use. With the rece...

The endocannabinoid signaling system (eCBs) regulates various physiological processes and is considered a potential pharmaceutical target for modulating emotional responses. Cannabidiol (CBD), a phytocannabinoid, enhances the action of eCBs and has an a...

Pain is one of the most common reasons to seek medical attention and chronic pain is a worldwide epidemic. Under some circumstances, incoming protective nociceptive signaling is prolonged leading to behavioral sensory alterations common to pathological ...

Tetrahydrocannabinol (THC) is the main psychoactive component of marijuana and exerts its pharmacological actions through activation of specific receptors highly expressed in the brain, namely cannabinoid receptors 1 (CB1) and 2 (CB2). Increasing eviden...

Synthetic cannabinoid (CB) agonists, such as WIN55,212-2 and CP55,940, are widely utilized to examine the acute physiological effects of CB receptor activation in the CNS. In most brain regions, these compounds inhibit the release of both glutamate and ...