Acute or chronic exposure to tetrahydrocannabinol (THC), the primary psychotropic component of cannabis, is known to induce schizophrenia-like symptoms in humans and other animals. The developing brain is particularly sensitive to the effects of THC. Wh...

Adolescent exposure to alcohol or delta-9-tetrahydrocannabinol (THC), which is the main psychoactive component in cannabis, has been associated with structural and functional changes in the brain of adult humans and laboratory animals. Considerably less...

More than 500 molecules have been identified as components of Cannabis sativa, of which the most studied is Δ9-tetrahydrocannabinol (Δ9-THC). Several studies have indicated that Δ9-THC exerts diverse biological effects, ranging from fragmentation of DNA...

The potential of repeated exposure to delta-9-tetrahydrocannabinol (THC) to produce long lasting changes in synaptic connections in a manner similar to other drugs of abuse was evaluated in Sprague-Dawley rats. For 14 days, rats received two intraperitoneal injections per day (8 hr apart) of vehicle, a low dose of THC (0.5 mg/kg) or escalating doses of THC (0.5 – 4.0 mg/kg). Thirty days later, they were evaluated for sensitized locomotor activity (during the night cycle) for 60 min on each of three trials. Using a within-groups design, rats were tested following an injection of vehicle, 0.5 mg/kg THC or 2.0 mg/kg. The rats showed no evidence of sensitized locomotor activity in any group. On Day 33, their brains were removed and then processed for Golgi-Cox staining. Prior exposure to THC (both the low dose and the escalating doses) increased the length of the dendrites as well as the number of dendritic branches in the shell of the nucleus accumbens and in the medial prefrontal cortex. There were no signif...

Increased eating is a common effect of systemically-administered cannabinoid drugs in both humans and rats. Microinjections of these drugs into the nucleus accumbens shell (NAc) and other brain areas can also increase feeding in rats. The psychological mechanism of these effects is as yet unknown, however. In particular, it is unknown whether cannabinoids actually increase palatability of tastes (‘liking’), beyond elevating food intake. The taste reactivity test is a useful way to assess changes in hedonic impact of taste palatability in rats. In these experiments, we tested whether intra-nucleus accumbens microinjections of anandamide altered positive hedonic reactions (e.g. tongue protrusions, paw licking) elicited by oral infusions of sucrose solution. We then compared these hedonic effects to effects of the same microinjections on food intake. These results provide insight into the involvement of NAc cannabinoid receptors in food ‘liking’ vs. ‘wanting.’.

Cannabidiol (CBD) is one of the major cannabinoids present in Cannabis sativa with great therapeutic potential. According to evidence from preclinical and clinical studies, CBD was shown to have anticonvulsive effect and has recently been proposed for t...

Curcumin (Curc) and tetrahydrocurcumin (THC) are both phenolic compounds, exerting antioxidant and anti-inflammatory properties that contribute to neuroprotection, for example, in Alzheimer’s Disease (AD) and in chemoprevention. One inflammatory pathway that has been implicated in both diseases is iNOS which catalyzes the production of nitric oxide (NO). Here we examine the bioavailability and anti-inflammatory effects of Curc and THC with different routes of administration: (gavage, GV; intra-muscular, IM; or intra-peritoneal, IP). Mice were injected IP with LPS (lipopolysaccharide, 0.5 µg/g body weight) or vehicle and iNOS production measured in mouse brain. We administered Curc and THC by GV, IP and IM (0.4, 0.4,and 0.2µmoles, respectively) to C57bl mice with or without LPS and collected their plasma and brain. IM-injected Curc and THC resulted in their elevation in plasma and brain by HPLC detection,and significantly reduced CNS iNOS production by Western. Two-step QPCR studies of mouse brain tissue al...

Throughout the world, cannabis remains one of the most widely used illicit drugs during pregnancy (Porath-Waller, 2015). The main psychoactive component of marijuana (delta9-tetrahydrocannabinol, THC) passes through the placenta, and its use is correlat...

To estimate the effects of Delta-9-THC on locomotion activities, we used multiple-channel, single unit recording technique to investigate the neuronal activity in the dorsal striatum, the globus pallidus, the subthalamic nucleus and the substantia nigra pars reticulata during freely moving and treadmill locomotion tasks in rats. Sixty-four stainless steel microwires were implanted in those brain areas and neuronal activity were recorded simultaneously with a 64 channel recording device. Six infrared beams were used to measure the locomotion activity in the open field condition. Delta-9-THC pre-treatment (0.05-2.0mg/kg, i.p.) caused a decrease in locomotion activity in a clear dose dependent manner. Delta-9-THC treatment resulted in significant inhibition in the neural activities across all four basal ganglia areas recorded in the freely moving conditions. A treadmill task was employed to test the actions of Delta-9-THC in different behavioral contexts. Each trial consists of 20 seconds walking followed by ...

Cannabinoid receptor agonists may produce anxiogenic and anxiolytic effects in rats. Clinical reports suggest that cannabidiol (CBD) attenuates aversive effects of Δ9-tetrahydrocannabinol (Δ9-THC). We investigated the effects of Δ9-THC and CBD on conditioned and unconditioned aversion. Male Lister-Hooded rats (250-300g, n=6-8) received (i.p.)Δ9-THC (1 or 10 mg/kg), CBD (5 or 50 mg/kg) or vehicle (ethanol:cremophor:saline; 1:1:18) 30 min prior to aversive conditioning (10x1s foot shocks, 0.4mA, 1 min intervals). After 24 hrs, duration of contextually-induced freezing was scored. Separate groups of rats received (i.p.) Δ9-THC (1 mg/kg), Δ9-THC (1 mg/kg) + CBD (5 mg/kg), CBD (5 mg/kg) or vehicle 30 min prior to 3 min exposure to ultrasound (20kHz, 85dB). Freezing and explosive hyperlocomotor activity were scored. Drug effects on locomotor activity were assessed separately in activity boxes. Data analysed by one-way ANOVA and Duncan’s multiple range test. Contextually-induced freezing was significantly attenua...