This study determined whether the cannabis constituent cannabidiol attenuates the development of morphine reward in the conditioned place preference paradigm. Mice received either saline or morphine in combination with increasing doses of cannabidiol us...

Marijuana remains the most commonly abused illicit substance in the United States, however, the effects of cannabis on cerebral blood volume (CBV) have not been fully examined. Given reported changes in frontal BOLD activation in marijuana smokers the objective of the present study was to examine both cerebral (frontal and temporal areas) and cerebellar blood volume during a period of supervised abstinence. Dynamic susceptibility contrast (DSC) MRI data were collected on eleven current, long-term marijuana users (MJ) between 6 hours and 36 hours after the subject's last reported cannabis use. Resting state CBV images were also acquired in 11 healthy comparison subjects (NCs). Data were acquired in the axial plane following a bolus of gadolinium contrast agent with a 1.5-Tesla GE Signa scanner. MJ smokers demonstrated significantly increased blood volumes in the left temporal area (p= 0.018) and in the cerebellum (p= 0.023) relative to control subjects. A regression analysis revealed that age was not signif...

We have previously shown that cannabinoid agonists, including delta-9-tetrahydrocannabinol (THC), are more potent and in some cases more efficacious in female than in male rats, in terms of their antinociceptive and motoric effects (Tseng & Craft, Eur J Pharmacol 430:41, 2001). In the present study, we manipulated gonadal steroid hormone state in adulthood, to determine to what extent activational effects of gonadal steroids are responsible for sex differences in sensitivity to the behavioral effects of THC. Adult Sprague-Dawley rats were gonadectomized; half of the females were implanted s.c. with estradiol (1-mm capsule/rat), and half of the males were implanted with testosterone (10-mm capsule/100 g body weight), and the rest of the rats were implanted with blank capsules of comparable length and number. Three weeks later, rats were injected with THC (5 mg/kg i.p.) or vehicle (1:1:18 emulphor:ethanol:saline) and tested for antinociception (tail withdrawal and paw pressure tests) and motor behaviors (hor...

The aim of this study was to evaluate the effects of cannabidiol (CBD) in alcohol reinforcement, motivation and relapse in C57BL/6J mice. To this purpose, the effects of CBD (60 mg/kg i.p.) and ethanol on rectal temperature (3 g/kg p.o.), ethanol-handli...

Marijuana consumption elicits diverse physiological and psychological effects in humans, including memory loss. Here we report that Δ9-tetrahydrocannabinol (THC), the major psychoactive component of marijuana, is toxic for hippocampal neurons. Treatment of cultured neurons or hippocampal slices with THC caused shrinkage of neuronal cell bodies and nuclei as well as genomic DNA strand breaks, hallmarks of neuronal apoptosis. Neuron death induced by THC was inhibited by nonsteroidal anti-inflammatory drugs, including indomethacin and aspirin, as well as vitamin E and other antioxidants. Furthermore, treatment of neurons with THC stimulated a significant increase in the release of arachidonic acid. We hypothesize that THC neurotoxicity is attributable to activation of the prostanoid synthesis pathway and generation of free radicals by cyclooxygenase. These data suggest that some of the memory deficits caused by cannabinoids may be caused by THC neurotoxicity.

Anxiety disorders are becoming more prevalent every year, with almost 19% of the adult population suffering from some sort of anxiety disorder within the past year. Due to a variety of biological and social factors, females are more likely to be diagnos...

Week of July 2, 2018: Read the Latest Advocacy and Science News

Evidence suggests that the phytocannabinoids Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) differentially regulate salience attribution and psychiatric risk. The ventral hippocampus (vHipp) relays emotional salience via control of dopamine (DA) neuronal activity states, which are dysregulated in psychosis and schizophrenia. Using in vivo electrophysiology in male Sprague Dawley rats, we demonstrate that intra-vHipp THC strongly increases ventral tegmental area (VTA) DA neuronal frequency and bursting rates, decreases GABA frequency, and amplifies VTA beta, gamma and ε oscillatory magnitudes via modulation of local extracellular signal-regulated kinase phosphorylation (pERK1–2). Remarkably, whereas intra-vHipp THC also potentiates salience attribution in morphine place-preference and fear conditioning assays, CBD coadministration reverses these changes by downregulating pERK1–2 signaling, as pharmacological reactivation of pERK1–2 blocked the inhibitory properties of CBD. These results identify vHipp...

Cannabis is the most widely used illicit drug and its use is often associated with psychiatric disorders. THC is an agonist of cannabinoid 1 and 2 receptors (CB1R, CB2R), through which it acts on brain reward systems to increase dopamine (DA) neuron act...

The present investigation assessed the neuroprotective efficacy of cannabidiol (CBD) in a kainic acid (KA) seizure model of temporal lobe epilepsy. Sixty-six male Sprague-Dawley rats were used. Each animal was housed individually in a clear polycarbonat...