RESUMO
Although the use, and misuse, of methylphenidate is increasing in childhood and adolescence, there is little information about the consequences of this psychostimulant chronic use on brain and behavior during development. The aim of the present study was to investigate hippocampus biochemical, histochemical, and behavioral effects of chronic methylphenidate treatment to juvenile rats. Wistar rats received intraperitoneal injections of methylphenidate (2.0 mg/kg) or an equivalent volume of 0.9 % saline solution (controls), once a day, from the 15th to the 45th day of age. Results showed that chronic methylphenidate administration caused loss of astrocytes and neurons in the hippocampus of juvenile rats. BDNF and pTrkB immunocontents and NGF levels were decreased, while TNF-α and IL-6 levels, Iba-1 and caspase 3 cleaved immunocontents (microglia marker and active apoptosis marker, respectively) were increased. ERK and PKCaMII signaling pathways, but not Akt and GSK-3ß, were decreased. SNAP-25 was decreased after methylphenidate treatment, while GAP-43 and synaptophysin were not altered. Both exploratory activity and object recognition memory were impaired by methylphenidate. These findings provide additional evidence that early-life exposure to methylphenidate can have complex effects, as well as provide new basis for understanding of the biochemical and behavioral consequences associated with chronic use of methylphenidate during central nervous system development.
Assuntos
Astrócitos/patologia , Comportamento Animal/efeitos dos fármacos , Hipocampo/patologia , Metilfenidato/toxicidade , Neurônios/patologia , Animais , Antígenos Nucleares/metabolismo , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Citocinas/metabolismo , Comportamento Exploratório/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Modelos Biológicos , Fatores de Crescimento Neural/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Wistar , Reconhecimento Psicológico , Transdução de Sinais , Proteína 25 Associada a Sinaptossoma/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Aim: This study aimed to compare the microbiological potential and gustatory perception of essential oils (EO) mouthrinses containing and not containing alcohol. Methods: Twenty healthy adult volunteers rinsed with 10mL of the following test solutions: EO with alcohol, EO without alcohol, or a control solution (saline solution with mint essence). A washout period of at least seven days was adopted after a single-use protocol of the respective solution. All participants used all three tested substances. Antimicrobial potential was assessed by counting salivary total viable bacteria both before and after each rinse. Gustatory perception was evaluated using the Visual Analogue Scale (VAS). Multiple comparisons were performed with the Wilcoxon test, using Bonferroni correction. Results: Both EO solutions presented a higher antimicrobial potential in comparison to the control solution (p<0.017). However, no significant difference in antimicrobial potential was observed between EO containing or not containing alcohol (p=0.218). VAS of EO with alcohol (median: 2.7) was similar to control solution (median: 1.6) (p=0.287). A better gustatory perception was observed of the EO without alcohol (median 7.6) when compared to the control solution (p<0.0001). When EO groups were compared, EO without alcohol also demonstrated a significantly better gustatory perception (p=0.001). Conclusion: Mouthrinse containing EO without alcohol presented a better taste perception when compared to the EO with alcohol, but no difference was observed in the antimicrobial potential of both EO solutions after a single rinse protocol