RESUMO
The retinohypothalamic tract is one component of the optic nerve that transmits information about environmental luminance levels through medial and lateral branches to four major terminal fields in the hypothalamus. The spatial distribution and organization of axonal projections from each of these four terminal fields were analyzed and compared systematically with the anterograde pathway tracer PHAL in rats where the terminal fields had been labeled with intravitreal injections of a different anterograde pathway tracer, CTb. First, the well-known projections of two medial retinohypothalamic tract targets (the ventrolateral suprachiasmatic nucleus and perisuprachiasmatic region) were confirmed and extended. They share qualitatively similar projections to a well-known set of brain regions thought to control circadian rhythms. Second, the projections of a third medial tract target, the ventromedial part of the anterior hypothalamic nucleus, were analyzed for the first time and shown to resemble qualitatively those from the suprachiasmatic nucleus and perisuprachiasmatic region. And third, projections from the major lateral retinohypothalamic tract target were analyzed for the first time and shown to be quite different from those associated with medial tract targets. This target is a distinct core part of the ventral zone of the anterior group of the lateral hypothalamic area that lies just dorsal to the caudal two-thirds of the supraoptic nucleus. Its axonal projections are to neural networks that control a range of specific goal-oriented behaviors (especially drinking, reproductive, and defensive) along with adaptively appropriate and complementary visceral responses and adjustments to behavioral state.
Assuntos
Axônios/fisiologia , Hipotálamo/citologia , Hipotálamo/fisiologia , Retina/citologia , Retina/fisiologia , Vias Visuais/citologia , Vias Visuais/fisiologia , Animais , Núcleo Hipotalâmico Anterior/citologia , Núcleo Hipotalâmico Anterior/fisiologia , Axônios/ultraestrutura , Comportamento Animal/fisiologia , Ritmo Circadiano/fisiologia , Região Hipotalâmica Lateral/citologia , Região Hipotalâmica Lateral/fisiologia , Masculino , Técnicas de Rastreamento Neuroanatômico/métodos , Ratos , Ratos Wistar , Núcleo Supraquiasmático/citologia , Núcleo Supraquiasmático/fisiologiaRESUMO
O objetivo deste estudo foi avaliar a ocorrência de parasitas em crianças da Comunidade da Vila Inglesa em São Paulo, SP, Brasil. Os exames coproparasitológicos realizados em amostras coletadas de 66 crianças evidenciaram resultados positivos em 69,7% em que os mais prevalentes foram Endolimax nana (48,4%), Entamoeba coli (40,9%) e Giardia lamblia (10,7%). Observou-se que 25,8% das crianças estavam infectadas por mais de um protozoário. Esses achados mostram que as enteroparasitoses ainda representam um sério problema de saúde pública em determinadas comunidades e que há necessidade de programas de saúde para orientar a população a respeito de educação sanitária para a prevenção de doenças.
This study aimed at investigating the enteroparasitosis occurrence in children of the Vila Inglesa community in São Paulo, SP, Brazil. Coproparasitological analyses performed in samples collected from 66 children revealed that 69.7% were infected with protozoa, being Endolimax nana (48.4%), Entamoeba coli (40.9%) and Giardia lamblia (10.7%) the mostly prevalent. It was also observed that 25.8% of the analyzed children were infected with more than one protozoa species. These findings show that enteroparasitosis remains to be a serious problem of public heath in certain communities, and that a health program needs to beimplemented for guiding the population on how the sanitation education can help for preventing diseases.