The aim of the present study was to analyze the influence of enriched environment on the distribution of perineuronal nets (PNNs) using a stereogically based unbiased protocol and visual acuity in adult Swiss albino mice that underwent monocular deprivation during the critical period of postnatal development. Eight female Swiss albino mice were monocular deprived on postnatal day 10 and divided into two groups at weaning: standard environment (SE group, n = 4) and enriched environment (EE group, n = 4). After 3 months, all of the mice were subjected to grating visual acuity tests, sacrificed, and perfused with aldehyde fixative. The brains were removed and cut at 70 µm thickness in a vibratome and processed for lectin histochemical staining with Wisteria floribunda agglutinin (WFA). Architectonic limits of area 17 were conspicuously defined by WFA histochemical staining, and the optical fractionator stereological method was applied to estimate the total number of PNNs in the supragranular, granular, and infragranular layers. All groups were compared using Student's t-test at a 95% confidence level. Comparative analysis of the average PNN estimations revealed that the EE group had higher PNNs in the supragranular layer (2726.33 ± 405.416, mean ± standard deviation) compared with the SE group (1543.535 ± 260.686; Student's t-test, p = .0495). No differences were found in the other layers. Visual acuity was significantly lower in the SE group (0.55 cycles/degree) than in the EE group (1.06 cycles/degree). Our results suggest that the integrity of the specialized extracellular matrix PNNs of the supragranular layer may be essential for normal visual acuity development.

O objetivo deste estudo foi avaliar a atividade antimicrobiana do extrato da folha de Myrciaria cauliflora (Mart.) O. Berg., Myrtaceae (jabuticabeira) sobre: Streptococcus mitis (ATCC 903), Streptococcus mutans (ATCC 25175), Streptococcus sanguinis (ATCC 15300), Streptococcus oralis (ATCC 10557), Streptococcus salivarius (ATCC 7073) e Lactobacillus casei (ATCC 9595). A pesquisa foi realizada através de técnicas bacteriológicas laboriosas. Os ensaios foram realizados pelo método da diluição em meio sólido para a determinação da Concentração Inibitória Mínima (CIM). Os resultados obtidos foram transferidos para um banco de dados informatizado e calculados os parâmetros estatísticos mediante o emprego do programa SPSS versão 13.0. Utilizou-se, ao nível de 5% de significância, o teste t-Student. Em estudo comparativo, foi determinada a CIM do digluconato de clorexidina a 0,12%. O extrato de jabuticabeira formou halos de inibição variando de 10 a 18 mm de diâmetro e apresentou desempenho médio significativamente inferior em relação a clorexidina, na comparação do extrato bruto vs substância pura e nas concentrações 1:2 e 1:4. Conclui-se, que o extrato de Myrciaria cauliflora produziu uma significante atividade bacteriostática in vitro sobre as bactérias do biofilme dental, o que sugere a utilização dessa substância como meio alternativo e economicamente viável para o controle de afecções em Odontologia.

The aim of this study was to evaluate in vitro antimicrobial activity of Myrciaria cauliflora (Mart.) O. Berg., Myrtaceae leaves extract on: Streptococcus mitis (ATCC 903), Streptococcus mutans (ATCC 25175), Streptococcus sanguinis (ATCC 15300), Streptococcus oralis (ATCC 10557), Streptococcus salivarius (ATCC 7073) and Lactobacillus casei (ATCC 9595). The study was done using laborious bacteriological techniques. The assays were made through dilution in agar diffusion method in order to reach the Minimum Inhibitory Concentration (MIC) determination. The results obtained were transferred for database and had the statistics parameter calculated by SPSS program 13.0 version. The t-Student test was used with 5% of significance. In comparative study, the digluconate of chlorexidine (0,12%) was determinated. The leaf extract of Myrciaria cauliflora Berg. formed halos of inhibition oscillating between 10-18 mm of diameter and it showed middle performance significantly inferior in respect to digluconate of chlorexidine (0,12%), on the pure extract and in the concentrations 1:2 and 1:4. It follows that, the Myrciaria cauliflora Berg. extract produced a significative in vitro bactericidal activity on the former oral biofilm bacterias, that suggests the use of these substances as an economic and viable kind of alternative to the control of odontological diseases.