Lack of effects between rupatadine 10 mg and placebo on actual driving performance of healthy volunteers

Introduction Rupatadine fumarate is a potent, selective, histamine H1-receptor antagonist and PAF inhibitor with demonstrated efficacy for the relief of allergic rhinitis. Rupatadine does not easily cross the blood–brain barrier and is believed to be non-sedating at therapeutic doses. Consequently, rupatadine should show no impairment on car driving. Objective This study compared the acute effects of rupatadine, relative to placebo and hydroxyzine (as an active control), on healthy subjects ’ driving performance

Rivastigmine but not vardenafil reverses cannabis-induced impairment of verbal memory in healthy humans

RATIONALE: One of the most often reported cognitive deficits of acute cannabis administration is an impaired recall of previously learned information. OBJECTIVE: The aim of the present study was to determine whether cannabis-induced memory impairment in humans is mediated via glutamatergic or cholinergic pathways. METHODS: Fifteen occasional cannabis users participated in a double-blind, placebo-controlled, six-way cross-over study. On separate test days, subjects received combinations of pretreatment (placebo, vardenafil 20 mg or rivastigmine 3 mg) and treatment (placebo or 1,376 mg cannabis/kg body weight). Cognitive tests were administered immediately after inhalation of treatment was finished and included measures of memory (visual verbal learning task, prospective memory test, Sternberg memory test), perceptual-motor control (critical tracking task), attention (divided attention task) and motor impulsivity (stop signal task). RESULTS: The results of this study demonstrate that subjects under the influence of cannabis were impaired in all memory tasks, in critical tracking, divided attention and the stop signal task. Pretreatment with rivastigmine attenuated the effect of cannabis on delayed recall and showed a trend towards significance on immediate recall. When cannabis was given in combination with vardenafil, there were no significant interaction effects in any of the tasks. CONCLUSIONS: The present data therefore suggest that acetylcholine plays an important role in cannabis-induced memory impairment, whereas similar results for glutamate have not been demonstrated in this study

How Gibbs distributions may naturally arise from synaptic adaptation mechanisms. A model-based argumentation

This paper addresses two questions in the context of neuronal networks dynamics, using methods from dynamical systems theory and statistical physics: (i) How to characterize the statistical properties of sequences of action potentials ("spike trains") produced by neuronal networks ? and; (ii) what are the effects of synaptic plasticity on these statistics ? We introduce a framework in which spike trains are associated to a coding of membrane potential trajectories, and actually, constitute a symbolic coding in important explicit examples (the so-called gIF models). On this basis, we use the thermodynamic formalism from ergodic theory to show how Gibbs distributions are natural probability measures to describe the statistics of spike trains, given the empirical averages of prescribed quantities. As a second result, we show that Gibbs distributions naturally arise when considering "slow" synaptic plasticity rules where the characteristic time for synapse adaptation is quite longer than the characteristic time for neurons dynamics.Comment: 39 pages, 3 figure

Cannabis and tolerance: acute drug impairment as a function of cannabis use history

Contains fulltext : 167132.pdf (publisher's version ) (Open Access)Cannabis use history as predictor of neurocognitive response to cannabis intoxication remains subject to scientific and policy debates. The present study assessed the influence of cannabis on neurocognition in cannabis users whose cannabis use history ranged from infrequent to daily use. Drug users (N = 122) received acute doses of cannabis (300 mug/kg THC), cocaine HCl (300 mg) and placebo. Cocaine served as active control for demonstrating neurocognitive test sensitivity. Executive function, impulse control, attention, psychomotor function and subjective intoxication were significantly worse after cannabis administration relative to placebo. Cocaine improved psychomotor function and attention, impaired impulse control and increased feelings of intoxication. Acute effects of cannabis and cocaine on neurocognitive performance were similar across cannabis users irrespective of their cannabis use history. Absence of tolerance implies that that frequent cannabis use and intoxication can be expected to interfere with neurocognitive performance in many daily environments such as school, work or traffic

Binding occurs at early stages of processing in children and adults

Conjoining features in a high-rate serial presentation was studied in children and adults using event-related potentials. Three blocks of trials were run in which targets were defined by colour, by orientation or by a conjunction of colour and orientation. Only adults had faster RTs when detecting targets defined by a single feature than by a combination of features. Compared with adults, children had longer RTs, longer N1 and P2 latencies, and larger P1 and P2 amplitudes. Amplitudes asymmetries were consistent with differing cortical regions being implicated in the processing of colour and form. There were, however, no EP latency effects as a function of task, suggesting that the binding of features proceeds in parallel with the processing of single features. NeuroReport 12:1949-195