Reinaldo Naoto Takahashi

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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. To evaluate the effects of the cannabinoid agonist WIN 55,212-2 (WIN) and the cannabinoid antagonist(More)
The present study investigated the central effects of the eCB uptake/metabolism inhibitor AM404 and the phytocannabinoid cannabidiol (CBD) on the extinction of contextual fear memories in rats. Rats were conditioned and 24 h later subjected to three consecutive 9-min non-reinforced exposures to the conditioning context (extinction sessions, 24 h intervals).(More)
Caffeine, a non-selective adenosine receptor antagonist, has been suggested as a potential drug to counteract age-related cognitive decline since critical changes in adenosinergic neurotransmission occur with aging. In the present study, olfactory discrimination and short-term social memory of 3, 6, 12 and 18 month-old rats were assessed with the olfactory(More)
Many studies have shown that deficits in olfactory and cognitive functions precede the classical motor symptoms seen in Parkinson's disease (PD) and that olfactory testing may contribute to the early diagnosis of this disorder. Although the primary cause of PD is still unknown, epidemiological studies have revealed that its incidence is increased in(More)
In addition to classic motor symptoms, Parkinson's disease (PD) is characterized by cognitive and emotional deficits, which have been demonstrated to precede motor impairments. The present study addresses the question of whether a partial degeneration of dopaminergic neurons using 6-hydroxydopamine (6-OHDA) in rats is able to induce premotor behavioral(More)
Object location task (OLT) has been used as a model of hippocampal-dependent memory. Despite this application, there is neither a consistent pharmacological validation of NMDA receptor modulation nor an evaluation of hippocampal participation in mice. In the OLT, mice were placed in the open field with two identical objects for 3 min and, after a delay of(More)
The memory deficits induced by cannabinoid agonists have been found in several behavioral paradigms. Nevertheless, there is evidence that not all types of memory are impaired after cannabinoid administration. The aim of this study was to investigate whether the cannabinoid agonist WIN 55212-2 (WIN) is able to influence the acquisition of fear conditioning(More)
Intra-nigral administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrindine (MPTP) caused a lesion in the substantia nigra, compact part (SNc) and a specific loss of dopamine and its metabolites in the striatum of rats. The animals were then tested in the two-way active avoidance task. MPTP-treated animals presented lower learning scores in the training(More)
Increased brain deposition of amyloid beta protein (Abeta) and cognitive deficits are classical signals of Alzheimer's disease (AD) that have been highly associated with inflammatory alterations. The present work was designed to determine the correlation between tumor necrosis factor-alpha (TNF-alpha)-related signaling pathways and inducible nitric oxide(More)
Facilitation of memory extinction by manipulation of the endocannabinoid (eCB) system has been recently studied in several paradigms. Our previous results pointed to facilitation of contextual fear memory extinction by a low dose of a cannabinoid agonist, with a suggestion of short-term effects. The aim of the present study was to further investigate the(More)