Biology subjects

Moore, C. F.

Publications and source records attributed to Moore, C. F..

3 recordsLinked to original sources

bioRxiv2021

Δ9-tetrahydrocannabinol (THC) vapor exposure produces conditioned rewarding effects in male and female rats

BackgroundThe use of place conditioning procedures and drug vapor exposure models can increase our understanding of the rewarding and aversive effects of vaped cannabis products. Currently there are limited data on the conditioned rewarding effects of vaporized {Delta}9-tetrahydrocannabinol (THC), the primary psychoactive constituent of cannabis in rats, and no studies to date examining sex differences. MethodsMale and female Sprague-Dawley rats (N=96; 12 per sex/group) underwent place conditioning sessions immediately after exposure to THC or vehicle (propylene glycol, PG) vapor. Locomotor activity was measured by beam breaks during conditioning sessions. THC vapor-conditioned rats received one of three THC vapor exposure amounts (low: 5 puffs of 100 mg/ml THC, medium: 5 puffs of 200 mg/ml THC, or high: 10 puffs of 200 mg/ml THC) and matched vehicle vapor (PG) exposure on alternate days for 16 daily sessions. A no THC control group of vehicle-conditioned rats received only PG vapor exposure each day. After the 8th and 16th conditioning sessions, untreated rats were tested for conditioned place preference (CPP) or avoidance (CPA). Next, extinction tests and a THC vapor-primed reinstatement test were conducted. ResultsTHC vapor produced CPP and locomotor effects in an exposure dependent manner, and some sex differences were observed. Low THC vapor exposure did not produce CPP in males or females. Medium THC vapor exposure produced CPP in males, but not females. High THC vapor exposure produced CPP in both males and females. Medium and high THC vapor exposure amounts produced hyperactivity in female rats, but not male rats. CPP was more resistant to extinction in females than males. THC vapor re-exposure (i.e., drug-prime) after extinction did not result in reinstatement of CPP for either sex. ConclusionThis study demonstrates conditioned rewarding effects of THC vapor in both male and female rats and provides evidence for sex differences in amounts of THC vapor that produce CPP and in time to extinction. CPA was not observed at any of the THC vapor exposure amounts tested. These data provide a foundation for future exploration of the conditioned effects of cannabis constituents and extracts using vapor exposure models.

animal behavior and cognition↗

bioRxiv2021

Cannabinoid tetrad effects of oral Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in male and female rats: sex, dose-effects and time course evaluations

Rationale The legalization of medicinal use of Cannabis sativa in most US states and the removal of hemp from the Drug Enforcement Agency (DEA) controlled substances act has resulted in a proliferation of products containing {Delta}9-tetrahydrocannabinol (THC) and cannabidiol (CBD) for oral consumption (e.g., edibles, oils and tinctures) that are being used for recreational and medicinal purposes. Objective This study examined the effects of cannabinoids THC and CBD when administered orally on measures of pain sensitivity, body temperature, locomotor activity, and catalepsy (i.e., cannabinoid tetrad) in male and female Sprague Dawley rats. Methods Rats (N=24, 6 per sex/drug group) were administered THC (1-20 mg/kg), CBD (3-30 mg/kg), or sesame oil via oral gavage. Thermal and mechanical pain sensitivity (tail flick assay, von Frey test), rectal measurements for body temperature, locomotor activity, and the bar-test of catalepsy were completed. A separate group of rats (N=8/4 per sex) were administered morphine (5-20 mg/kg; intraperitoneal, IP) and evaluated for pain sensitivity as a positive control. Results We observed classic tetrad effects of antinociception, hypothermia, hyper- and hypolocomotion, and catalepsy after oral administration of THC that were long lasting (>7 hours). CBD modestly increased mechanical pain sensitivity and produced sex-dependent effects on body temperature and locomotor activity. Conclusions Oral THC and CBD produced long lasting effects, that differed in magnitude and time course when compared with other routes of administration. Examination of cannabinoid effects administered via different routes of administration, species, and in both males and females is critical to enhance translation.

pharmacology and toxicology↗

bioRxiv2020

Antinociceptive, hypothermic, and appetitive effects of vaped and injected Δ9-tetrahydrocannabinol (THC) in rats: exposure and dose-effect comparisons by strain and sex

Advances in drug vapor exposure systems utilizing e-cigarette technology have enabled evaluation of {Delta}-9-tetrahydrocannabinol (THC) vapor effects in laboratory animals. The purpose of this study was to 1) establish a range of parameters of THC vapor exposure in rats sufficient to produce a behavioral dose-effect curve in a battery of tasks sensitive to THC; 2) to investigate sex differences in the effects of THC vapor exposure and THC injection (intraperitoneal, IP) on these behaviors in two strains of outbred rats. Male and female Wistar and Sprague Dawley rats (N=22, 5-6/group) received THC via IP injection (1-20 mg/kg) and passive exposure to THC vapor (200 mg/ml; 5 conditions) in a within subject design. The effects of vaped and injected THC were determined using the tail-withdrawal assay for nociception, rectal measurements of body temperature, and progressive-ratio responding for food pellets. Plasma THC concentrations were assessed after 10 mg/kg IP THC or THC vapor. THC produced dose and exposure-dependent antinociception and hypothermia. THC vapor produced inverted U-shaped effects in motivation to obtain food, while IP THC reduced PR breakpoints. Plasma THC concentrations were higher after 10 mg/kg IP THC (152 ng/mL) compared to the highest vapor exposure condition tested (38 ng/mL). THC vapor exposure produces reliable, dose-orderly effects on nociception, body temperature, and food-maintained behavior that is comparable to effects observed after IP THC. There are considerable differences between the time course of behavioral outcomes produced by these two different routes of administration.

animal behavior and cognition↗