Banca de QUALIFICAÇÃO: DANIELE OLIVEIRA SOUZA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : DANIELE OLIVEIRA SOUZA
DATA : 23/11/2018
HORA: 08:00
LOCAL: Auditório do PPg em Biologia Estrutural e Funcional
TÍTULO:

Study of Lippia alba essential oil treatment in rats with chronic neuropathic pain induced by chronic constriction of the sciatic nerve: evaluation of the electrophysiological and morphological parameters of the sciatic nerve and dorsal root ganglion

PALAVRAS-CHAVES:

Peripheral nervous system; ciatic nerve; ciatic constriction; eletrophysiology; dorsal root ganglia.

PÁGINAS: 77
GRANDE ÁREA: Ciências Humanas
ÁREA: Psicologia
RESUMO:

Peripheral nerve lesions induce degeneration of injured axons, causing functional deficits, in which endogenous recovery mechanisms contribute to the occurrence of Neuropathic Pain (DN). Chronic constriction injury (CCNC) model is widely used for DN induction in experimental animals due to similarity of DN in humans. The adaptation of this model was necessary for a better development of functional evidence of the compound nerve action potential (PAC) in the electrophysiological evaluation. In this context, the present study aimed to evaluate the electrophysiological changes of the sciatic nerve, produced from the changes in anatomical location of the CCNC from the model of Bennett and Xie (1988). Rattus novergicus (Wistar) rats were used, both sexes, body mass ranging from 200-250 g. Divided into two groups: control and experimental group subjected to CCNC in the right hind paw of the rat. On the 14th day after CCNC the animals were euthanized. The dissection of right and left sciatic nerve was performed to analyze the PAC in the extracellular system. According to the results the technique of the CCNC model was modified, it was divided into four steps according to the CCNC localition and the camera used to record the PAC. In the 3rd and 4th stages, only in the proximal segment from the CCNC was analyzed. All PAC parameters measured were: Peak-to-Peak Amplitude (APP), chronaxia, positive amplitude reobase, and conduction velocity of the 1st and 2nd PAC components. In first stage, only the first component of the PAC was registered. In step two, no sign of PAC was noticed. In the 3rd stage, only one component of the PAC was registered. In the 4th stage, two components of the PAC were registered. All electrophysiological parameters were evaluated and compared between all the steps. However, to present this data, it was selected data from 1st and 4th stages. Because they are the stages that present the most different results among themselves. The CCNC surgery presented depressant effect on APP (1st stage: 71.12%, 4th stage: 57.39%), positive amplitude (1st stage: 75.84%, 4th stage: 47.66%) and conduction velocity of the first component of the PAC, which is just  a tendency for the 4th stage, not statistically significant. The reobase obtained an increase of 42.4% in the first stage and a reduction of 36.11% in the 4th stage. Chronaxia presented a tendency to increase in both stages. In the second component evidenced in the 4th stage, the positive amplitude of the PAC decreased, but it did not differ statistically from the control values. Conduction velocity presented a reduction of 33% of the control value. Therefore, electrophysiological records showed that CCNC affects myelinated and non-myelinated axons, compromising mainly the fibers that integrate the second component of the PAC. The other versions of this technique enable to verify the functionality changes of the PAC transmission according to the location of CCNC over the sciatic nerve, exploring the most efficient form of PAC signaling evidence.

MEMBROS DA BANCA:
Presidente - 4363493 - EXPEDITO SILVA DO NASCIMENTO JUNIOR
Externo ao Programa - 1076490 - FERNANDO VAGNER LOBO LADD
Externo ao Programa - 1733434 - RENATA FIGUEIREDO ANOMAL