Papel do córtex insular na modulação da ansiedade

Abstract

The insular cortex (IC) is a structure that connects many regions of the brain. It has been reported as an important modulator of emotions due to its links with limbic structures and has been associated with the modulation of anxiety-like behavior. Glutamate is the main excitatory neurotransmitter in the central nervous system and its association with nitric oxide (NO) and the enzyme soluble guanylate cyclase (sGC) is well described in the literature. Among the receptors for glutamate, the N-methyl D-aspartate (NMDA) receptor stands out in this study because it’s linked to the calcium influx and to the nitric oxide – cyclic guanosine monophosphate (NO/cGMP) signaling pathway. The antagonism of the NMDA receptor and it’s signaling pathway may demonstrate the involvement of IC in the neuromodulation of anxiety. Thus, the objective of this project is to study this mechanism, in order to establish a relationship between the behavior modulated by IC and the glutamatergic action. Anxiety disorders are the second leading cause of work disability, with a high incidence and prevalence worldwide, in addition to the lack of differential diagnoses and laboratory tests for the different types of disorder, thus being an alarming point for the health sciences. currently. Male Wistar rats was used in these experiments which is based on stereotaxis surgery for cannulation of the insular cortex, where the drugs were administered directly, and then submitted to the elevated plus maze test and the open field test, for evaluation of the rat’s behavior. The recording of images and counting of inputs and outputs of the LCE was supported by a recording software (AnyMaze). The animals were divided into groups where each received a type of drug, in addition to the naive and control groups. After the experiment, the brain was removed, cut in a cryostat and analyzed for the determination of the drug injection site. Statistical analysis (Kruskall-Wallis) showed no statistically significant difference in the number of entries and exits of the maze, as well as in the length of animal staying in the center or in the periphery of the open field. However, some descriptive analyses showed some interesting points. Some problems were found in the course of the experiments, negatively influencing the results also. The experimental protocol was approved by the Animal Use Ethics Committee (CEUA) of the Federal University of Lavras (UFLA).