Learn More
Behavioral categories were measured in rats left on an elevated plus-maze for 5 min, in addition to the traditional measures. Four independent factors emerged from a factor analysis. The variables that loaded highly and positively on Factor 1, seemingly related with anxiety, were: number of entries onto open arms, time spent on open arms, percentage of(More)
Anxiety disorders are heterogeneous and existing animal models do not discriminate specific types of anxiety. The elevated T-maze is being developed to fulfill this purpose. The apparatus consists of three elevated arms, one enclosed and two open. Inhibitory avoidance--representing learned fear--is measured by recording the time taken to leave the enclosed(More)
There are conflicting results on the function of 5-HT in anxiety and depression. To reconcile this evidence, Deakin and Graeff have suggested that the ascending 5-HT pathway that originates in the dorsal raphe nucleus (DRN) and innervates the amygdala and frontal cortex facilitates conditioned fear, while the DRN-periventricular pathway innervating the(More)
In order to assess the presence of anxiolytic properties in cannabidiol (CBD) the drug was tested in an elevated plus-maze model of anxiety, in rats. Doses of 2.5, 5.0 and 10.0 mg/kg significantly increased the entry ratio (open/total number of entries), an anxiolytic-like effect. CBD at a dose of 20.0 mg/kg was no longer effective. None of the doses of CBD(More)
To explore the role of 5-HT receptor subtypes in controlling aversion, we measured the effect of 5-HT1A and 5-HT2A/2C receptor agonists microinjected into the dorsal periaqueductal gray (DPAG) of rats on aversive behavior induced by electrical stimulation of the same brain area. The 5-HT1A agonists 8-OH-DPAT (4-16 nmol) and BAY-R-1531 (4-16 nmol) raised the(More)
In an attempt to analyze different types of anxiety, and at the same time assess memory, a new experimental model was developed. The apparatus, named the elevated T-maze, consisted of three arms of equal dimensions (50 x 10 cm) elevated 50 cm from the ground. One arm, enclosed by 40-cm high walls, was perpendicular to two open arms. The first experimental(More)
The effects of ipsapirone and cannabidiol (CBD) on healthy volunteers submitted to a simulated public speaking (SPS) test were compared with those of the anxiolytic benzodiazepine diazepam and placebo. Four independent groups of 10 subjects received, under a double-blind design, placebo or one of the following drugs: CBD (300 mg), diazepam (10 mg) or(More)
Earlier observations have shown that systematically injected minor tranquilizers decrease the aversive consequences of electrical stimulation of the dorsal periaqueductal gray (DPAG) matter of the rat brain. In order to verify if these drugs can act directly on the DPAG, chlordiazepoxide (CDP) and pentobarbital (PB) were locally injected into the dorsal(More)
The microinjection of 80, 160 and 320 nmol chlordiazepoxide (CDP) as well as of 20, 40 and 80 nmol midazolam (MDZ) into the dorsal midbrain of rats bearing chronically implanted chemitrodes raised the threshold electrical current inducing escape behaviour by stimulating the dorsal periaqueductal grey matter (DPAG). Parallel linear regressions were obtained(More)