In order to establish histochemistry alterations occurring in Spreading Depression (SD) and the importance of anti-oxidative effect of carotenoid, this work evaluated three groups of cerebral cortex from adult rats. A group of induced SD and ethanol stressed shrimp carotenoid treated rats; an induced SD and ethanol stressed non-treated group and a control group (non-induced SD and non-ethanol stressed). Since SD is a propagation of neuronal activity suppression from a focal point throughout different cortical regions and that it is involved in events such as epilepsy, trauma as well as disturbs of brain function and protection, we used four lectins (Concanavalina A – Con A; Lotus tetragonolobus agglutinin – LTA; Arachis hypogaea agglutinin – PNA; Wheat germ - WGA) to evaluate carbohydrate alterations in brain glycoconjugates. Sections were treated with 0.1% (w/v) trypsin and 0.3% (v/v) methanol-H₂O₂ solutions and incubated with lectins conjugated to horseradish peroxidase. Haematoxylin was used for counter-staining and tissues were evaluated by light microscopy. In non-treated group Con A displayed a homogeneous and mainly membranous staining pattern, especially in layers II-III while pyramidals cells showed a perinuclear and homogeneous pattern in layer II. LTA showed a strong, homogeneous and granular-cytoplasmatic staining pattern of neurons in layers III-VI, while in I-II it was weak to absent. Pyramidals cells also showed a weak pattern. PNA showed a weak cytoplasmatic pattern in superficial layers, which becomes moderate, granular-cytoplasmatic at deeper ones. WGA did not show staining in layers I-II but in III-VI staining was weak and observed in few cells. In treated group, Con A, LTA and PNA showed a decrease of staining at all layers compared to treated group. WGA did not show significant difference in staining in relation to the non-treated group. Control group, when evaluated with Con A showed a heterogeneous, moderate and membranous pattern especially in layer III. LTA, PNA and WGA did not show any substantial change in the staining pattern. Results indicate that in SD alterations in carbohydrate profile in cortex cells are observed when comparing non-treated and control groups, and that shrimp carotenoids decreased such feature related to the expression and/or accessibility of saccharide moieties in glycoconjugates of cerebral cortex.
Supported by CNPq.