Pharmacokinetics of cannabidiol-/cannabidiolic acid-rich hemp oil in juvenile cynomolgus macaques (Macaca fascicularis).

Introduction: Cannabinoids are increasingly popular in human and veterinary medicine and have been studied as an alternative treatment for a wide range of disorders. The goal of this study was to perform a pharmacokinetic analysis of oral cannabidiol (CBD)-/cannabidiolic acid (CBDA)-rich hemp oil (CBD/ArHO) in juvenile cynomolgus macaques (Macaca fascicularis). Methods: After a 2 mg/kg CBD/ArHO pilot study, 4 and 8 mg/kg direct-to-mouth CBD/ArHO were administered (n = 4 per dose) once daily for 14 days and blood was collected at 0-, 0.5-, 1-, 2-, 4-, 8-, 12-, and 24-h, and on Days 7 and 14, to quantify serum cannabinoid concentrations by high-performance liquid chromatography-tandem mass spectrometry. Serum biochemistries and complete blood counts were performed on Days 0, 1, and 14. Results: The maximum mean serum concentration (Cmax) of CBDA was 28.6-36.2 times that of CBD at 4 and 8 mg/kg. At 8 mg/kg, the Cmax of CBD was 1.4 times higher (p = 0.0721), and CBDA was significantly 1.8 times higher (p = 0.0361), than at 4 mg/kg. The maximum mean serum concentration of ∆9-tetrahydrocannabinol (THC) was 4.80 ng/mL at 8 mg/kg. Changes in serum biochemistries and complete blood counts over time were not clinically significant. Discussion: Given the low serum CBD concentrations, the doses and frequency used in this study may be insufficient for a therapeutic effect of CBD in particular; therefore, clinical studies are needed to determine the therapeutic dose of CBD and CBDA for macaques, which may differ based on the disorder targeted.

Intraperitoneal Alfaxalone and Alfaxalone-Dexmedetomidine Anesthesia in Sprague-Dawley Rats (Rattus norvegicus).

Due to their unpredictability and variable effects, injectable anesthetic regimens in laboratory rodent species warrant refinement. In our study we sought to evaluate alfaxalone, which has gained recent popularity in veterinary medicine, alone and in combination with dexmedetomidine to evaluate their anesthetic ability in Sprague-Dawley rats when administered intraperitoneally. Three doses of alfaxalone only and 4 dose combinations of alfaxalone-dexmedetomidine were tested in males and female rats. The time to induction, anesthetic duration, pulse rate, respiratory rate, temperature, and time to recovery were recorded by a blind observer. The level of anesthesia induced by the various anesthetic protocols was assessed by using pedal withdrawal reflex to a noxious stimulus and scored according to the response. Dependent on the treatment group, atipamezole or saline was administered intraperitoneally once animals reached 60 min of anesthesia. Regardless of the dose, alfaxalone alone achieved only a sedative level of anesthesia, whereas all alfaxalone-dexmedetomidine combinations led to a surgical level of anesthesia in all animals. Anesthesia regimens using alfaxalone alone and in combination with dexmedetomidine demonstrated sex-associated differences, with female rats maintaining longer durations of sedation or anesthesia than their male counterparts. Both male and female rats displayed decreases in physiologic parameters consistent with the effects of dexmedetomidine. Given the results described herein, we recommend 20 mg/kg alfaxalone for sedation and 30 mg/kg alfaxalone combined with 0.05 mg/kg dexmedetomidine for surgical anesthesia in female rats. Appropriate doses of alfaxalone only and alfaxalone-dexmedetomidine for male rats were not determined in this study and need further evaluation.

Inferential reasoning in the visual and auditory modalities by cotton-top tamarins (Saguinus oedipus).

Nonhuman primate species appear to vary markedly in inferential reasoning abilities as measured by a classic inference-by-exclusion cup task. Even within species, individuals who can solve the cup task in the visual domain often struggle to use analogous auditory cues. Here we tested five cotton-top tamarins (Saguinus oedipus), cooperatively breeding New World monkeys that use both visual and auditory information when foraging, to investigate whether they might be able to solve the inference-by-exclusion task in both domains. Four subjects completed the testing series in both domains. Although three subjects performed well in the visual task, only one subject chose food location significantly above chance in response to positive auditory cues. These results demonstrate the first evidence of inferential reasoning abilities in a callitrichid species, while also revealing the performance asymmetry between the visual and auditory modalities observed in many other primates. (PsycINFO Database Record (c) 2019 APA, all rights reserved).