Azair Canto-de-Souza

Learn More
The biogenic amine histamine is an important neurotransmitter in the central nervous system that has been implicated in learning and memory processes. Experimental evidence indicates that the role of the cerebellum may be more complex than the simple regulation of motor responses, and recent studies have demonstrated significant involvement of the(More)
The effects of L-histidine (LH) on anxiety and memory retrieval were investigated in adult male Swiss Albino mice (weight 30-35 g) using the elevated plus-maze. The test was performed on two consecutive days: trial 1 (T1) and trial 2 (T2). In T1, mice received an intraperitoneal injection of saline (SAL) or LH before the test and were then injected again(More)
Studies have demonstrated the relationship between the histaminergic system and the cerebellum, and we intend to investigate the role of the cerebellar histaminergic system on memory consolidation. This study investigated the effect of intra-cerebellar microinjection of histamine on memory retention of inhibitory avoidance in mice, and the role of H1 and H2(More)
Histaminergic fibers are present in the molecular and granular layers of the cerebellum and have high density in the vermis and flocculus. Evidence indicates that the cerebellar vermis is involved in memory consolidation. Recently, we demonstrated that when histamine is microinjected into the cerebellar vermis it results in impaired emotional memory(More)
Intra-amygdala infusion of midazolam, a benzodiazepine receptor agonist, produces anxiolytic-like effects in mice when first exposed to the elevated plus-maze (EPM) and blocks antinociception induced in mice confined in the open arm of the EPM. However, benzodiazepines fail to alter anxiety in maze-experienced rodents, a phenomenon defined as "one-trial(More)
RATIONALE Mice exhibit antinociception after a single experience in the elevated plus maze (EPM), an animal model of anxiety. OBJECTIVE This study investigated the mechanisms involved in this form of anxiety-induced antinociception. METHODS Nociception was evaluated by means of the writhing test in mice confined either to the open or enclosed arms of(More)
The positive profile of systemically-administered 5-HT(1A) receptor antagonists in several rodent models of anxiolytic activity suggests an important role for postsynaptic 5-HT(1A) receptor mechanisms in anxiety. To test this hypothesis, we investigated the effects of WAY-100635 microinfusions (0, 0.1, 1.0 or 3.0 microg in 0.2 microl) into the dorsal (DH)(More)
Previous studies have demonstrated that microinjections of midazolam, a benzodiazepine receptor agonist, into the amygdala produce anxiolytic-like effects in elevated plus-maze (EPM)-naïve rodents. However, systemic or intracerebral administration of benzodiazepines (BDZ) fails to alter anxiety in maze-experienced animals, a phenomenon defined as "one trial(More)
Rodents can recognize pain-related responses in conspecifics. Therefore, cohabitation with a conspecific animal with chronic pain can potentially promote a stressful situation, which can trigger behavioral changes such as anxiety and depression and alter nociceptive responses. In this study we investigated the effect of cohabitation with a mouse undergoing(More)
Studies in several laboratories have confirmed the anxiolytic potential of a wide range of 5-HT(1A) receptor antagonists in rats and mice, with recent evidence pointing to a postsynaptic site of action in the ventral hippocampus. It would, therefore, be predicted that blockade of 5-HT(1A) somatodendritic autoreceptors in the midbrain raphe nuclei should(More)