Please use this link to access this publication. Abstract Frontotemporal dementia (FTD) and Alzheimer’s disease (AD) share the pathological hallmark of intracellular neurofibrillary tangles, which result from the hyperphosphorylation of microtubule associated protein tau. The P301S mutation in human tau carried by TAU58/2 transgenic mice results in brain pathology and behavioural deficits relevant to FTD and AD. The phytocannabinoid cannabidiol (CBD) exhibits properties beneficial for multiple pathological processes evident in dementia. Therefore, 14-month-old female TAU58/2 transgenic and wild type-like (WT) littermates were treated with 100 mg/kg CBD or vehicle i.p. starting three weeks prior to conducting behavioural paradigms relevant to FTD and AD. TAU58/2 females exhibited impaired motor function, reduced bodyweight and less...

Abstract Cannabis is now one of the most commonly used illicit substances among pregnant women. This is particularly concerning since developmental exposure to cannabinoids can elicit enduring neurofunctional and cognitive alterations. This study investigates the mechanisms of learning and memory deficits resulting from prenatal cannabinoid exposure (PCE) in adolescent offspring. The synthetic cannabinoid agonist WIN55,212-2 was administered to pregnant rats, and a series of behavioral, electrophysiological, and immunochemical studies were performed to identify potential mechanisms of memory deficits in the adolescent offspring. Hippocampal-dependent memory deficits in adolescent PCE animals were associated with decreased long-term potentiation (LTP) and enhanced long-term depression (LTD) at hippocampal Schaffer...

Abstract Working memory is an executive function that orchestrates the use of limited amounts of information, referred to as working memory capacity, in cognitive functions. Cannabis exposure impairs working memory in humans; however, it is unclear if Cannabis facilitates or impairs rodent working memory and working memory capacity. The conflicting literature in rodent models may be at least partly due to the use of drug exposure paradigms that do not closely mirror patterns of human Cannabis use. Here, we used an incidental memory capacity paradigm where a novelty preference is assessed after a short delay in spontaneous recognition-based tests. Either object or odor-based stimuli were used in test variations with...

Abstract Cannabis is one of the oldest crops grown, traditionally held religious attachments in various cultures for its medicinal use much before its introduction to Western medicine. Multiple preclinical and clinical investigations have explored the beneficial effects of cannabis in various neurocognitive and neurodegenerative diseases affecting the cognitive domains. Tetrahydrocannabinol (THC), the major psychoactive component, is responsible for cognition-related deficits, while cannabidiol (CBD), a non-psychoactive phytocannabinoid, has been shown to elicit neuroprotective activity. In the present integrative review, the authors focus on the effects of cannabis on the different cognitive domains, including learning, consolidation, and retrieval. The present study is the first attempt in...

Abstract   A generally undesired effect of cannabis smoking is a reversible disruption of short-term memory induced by delta-9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis. However, this paradigm has been recently challenged by a group of scientists who have shown that THC is also able to improve neurological function in old animals when chronically administered at low concentrations. Moreover, recent studies demonstrated that THC paradoxically promotes hippocampal neurogenesis, prevents neurodegenerative processes occurring in animal models of Alzheimer’s disease, protects from inflammation induced cognitive damage and restores memory and cognitive function in old mice. With the aim to reconcile these seemingly contradictory facts, this...

The effects of chronic exposure to cannabinoids on short-term memory in rats were assessed during repeated daily injections of an initially debilitating dose (3.75 mg/kg) of the potent CB1 cannabinoid receptor ligand, WIN 55,212-2. Delayed nonmatch to sample (DNMS) performance was assessed over a 35-day exposure period in which performance was initially disrupted during the first 21 days of exposure but recovered by day 30 and was stable at pre-drug levels for 5 days thereafter. Withdrawal was precipitated by injections of the CB1 receptor antagonist SR141716A and transiently reduced performance for 2 days but was restabilized to pre-drug levels within 3– 4 days. Concomitant...

Rationale Previous studies demonstrated that pharmacological blockade of CB1 cannabinoid receptors decreases the extinction of conditioned fear and spatial memory in rodents. However, the effects of CB1 cannabinoid receptor activation in this response remain unclear. Objectives To evaluate the effects of the cannabinoid agonist WIN 55,212-2 (WIN) and the cannabinoid antagonist SR 147778 (SR) on the extinction of contextual fear memory in rats 24 h or 30 days after fear conditioning. Methods For fear conditioning, rats were placed in the conditioning chamber for 3 min and received a 1-s electric foot shock (1.5 mA). Retrieval testing consisted of a 3-min exposure to the conditioning...

The search for reconsolidation blockers may uncover clinically relevant drugs for disrupting memories of significant stressful life experiences, such as those underlying the posttraumatic stress disorder. Considering the safety of systemically administered cannabidiol (CBD), the major non-psychotomimetic component of Cannabis sativa, to animals and humans, the present study sought to investigate whether and how this phytocannabinoid (3–30 mg/kg intraperitoneally; i.p.) could mitigate an established memory, by blockade of its reconsolidation, evaluated in a contextual fear-conditioning paradigm in rats. We report that CBD is able to disrupt 1- and 7-days-old memories when administered immediately, but not 6 h, after their retrieval for 3 min, with...

The possible medicinal use of cannabinoids for chronic diseases emphasizes the need to understand the long-term effects of these compounds on the central nervous system. We provide a quantitative synthesis of empirical research pertaining to the non-acute (residual) effects of cannabis on the neurocognitive performance of adult human subjects. Out of 1,014 studies retrieved using a thorough search strategy, only 11 studies met essential a priori inclusion criteria, providing data for a total of 623 cannabis users and 409 non- or minimal users. Neuropsychological results were grouped into 8 ability domains, and effect sizes were calculated by domain for each study individually, and combined...

Abstract In an increasing number of states and countries, cannabis now stands poised to join alcohol and tobacco as a legal drug. Quantifying the relative adverse and beneficial effects of cannabis and its constituent cannabinoids should therefore be prioritized. Whereas newspaper headlines have focused on links between cannabis and psychosis, less attention has been paid to the much more common problem of cannabis addiction. Certain cognitive changes have also been attributed to cannabis use, although their causality and longevity are fiercely debated. Identifying why some individuals are more vulnerable than others to the adverse effects of cannabis is now of paramount importance to public...