The effect of the cannabinoid, Δ9-THC, on conditioned and unconditioned sickness was evaluated in the Suncus murinus, an emetic species. Experiment 1 demonstrated that, at the doses tested, THC did not suppress unconditioned vomiting elicited by lithium chloride. In a drug-free test of conditioned sickness, Experiment 2 revealed that shrews displayed conditioned gaping (a precursor to vomiting) when subsequently exposed to the lithium-paired chamber. THC suppressed conditioned gaping. These results support anecdotal suggestions that THC may reduce conditioned nausea in humans.

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 ...

Chronic intermittent administration of marijuana’s major psychoactive compound, ∆9-tetrahydro-cannabinol (THC) results in adaptive changes in adult social and cognitive functions that are dependent on activity of output neurons in the prelimbic prefront...

Cannabis is the illicit drug most commonly abused by pregnant women. The main psychoactive component of marijuana, delta9-tetrahydrocannabinol (∆9-THC), can reach the fetus through the placenta and the blood-brain barrier. Several longitudinal studies o...

Repeated THC administration produces motivational and somatic adaptive changes leading to dependence in rodents. To investigate the molecular basis for cannabinoid dependence and its possible relationship with the endogenous opioid system, we explored Δ9-tetrahydrocannabinol (THC) activity in mice lacking μ-, δ- or κ-opioid receptor genes. Acute THC-induced hypothermia, antinociception, and hypolocomotion remained unaffected in these mice, whereas THC tolerance and withdrawal were minimally modified in mutant animals. In contrast, profound phenotypic changes are observed in several place conditioning protocols that reveal both THC rewarding and aversive properties. Absence of μ receptors abolishes THC place preference. Deletion of κ receptors ablates THC place aversion and furthermore unmasks THC place preference. Thus, an opposing activity of μ- and κ-opioid receptors in modulating reward pathways forms the basis for the dual euphoric–dysphoric activity of THC.

Given the recent legalization of marijuana for both recreational and medical use in several states, cannabis use has increased, even among pregnant women. The most psychoactive constituent in cannabis, delta-9- tetrahydrocannabinol (Δ9-THC), crosses the...

Non-psychoactive, phytocannabinoids such as Cannabidiol (CBD) are potential anti-epileptic drugs (AED). CBD has given hope for patient groups with uncontrollable epilepsy where other drug treatments have failed, despite the lack of knowledge of the long...

Transient receptor potential V2 (TRPV2) has been proposed to be a high-threshold thermosensor. However, further elucidation of the channel properties and physiological role of TRPV2 have been hindered by the lack of selective pharmacological tools as well as by the species-dependent differences in the activation of this channel. In the present study, we have used cell-based calcium mobilization and electrophysiological assays to identify and characterize several novel cannabinoid TRPV2 agonists. Among these, cannabidiol was found to be the most robust and potent (EC50 = 3.7 μm), followed by Δ9-tetrahydrocannabinol (EC50 = 14 μm) and cannabinol (EC50 = 77.7 μm). We also demonstrated that cannabidiol evoked a concentration-dependent release of calcitonin gene-related peptide (CGRP) from cultured rat dorsal root ganglion neurons in a cannabinoid receptor- and TRPV1-independent manner. Moreover, the cannabidiol-evoked CGRP release depended on extracellular calcium and was blocked by the nonselective TRP channe...

Our understanding of the neural mechanisms underpinning addiction and relapse to marijuana has been hampered by the lack of a self-administration and relapse rodent model. We employ a novel protocol using intravenous self-administration of two constitue...

Psychostimulants as well as cannabinoids have been shown to affect a great variety of behaviors in both, humans and laboratory animals, in a serious manner. Our previous studies repeatedly demonstrated that control groups with saline injection(s) have d...