New directions in CNS drug delivery.

This commentary expands on the above article in 2 ways. First, it provides more recent information on polymer-based drug delivery systems. Second, it discusses experimental systems that may be clinically viable in the future such as prodrugs, cell-polymer transplants and gene transplants.

Distinct nigrostriatal projection systems innervate striosomes and matrix in the primate striatum.

Mesostriatal projections were labeled in 11 squirrel monkeys by injecting the anterograde tracer, [35S]methionine, into different parts of the dopamine-containing A8-A9-A10 cell complex of the midbrain. Two strikingly different compartmental patterns of mesostriatal projection were found. Fields of dense labeling in both the caudate nucleus and the putamen, interrupted by pockets of sparse labeling, were observed with deposits involving cell group A8, cell group A10 and/or the dorsally situated 'pars mixta' of the substantia nigra. Where striosomes could be identified as such in adjoining histochemically stained sections, the sparsely labeled zones were aligned with them. By contrast, a pattern of focally dense labeling in the caudate nucleus and putamen, with much weaker labeling surrounding the densely labeled zones, was found with injection sites centered in the horizontal band and associated ventrally extending fingers of the substantia nigra pars compacta. Many of the pockets of heightened labeling could be shown to correspond to histochemically defined striosomes. These compartmental patterns were identified both in the caudate nucleus and in the putamen. We conclude that the A8-A9-A10 cell complex of the primate contains spatially distinct subdivisions with preferential projections directed, respectively, toward the striosome and matrix compartments of the striatum.

Conservação de inimigos naturais (Insecta) em tomateiro orgânico / Conservation of natural enemies (Insecta) in the organic tomato crop

A adoção de práticas culturais como o consórcio de culturas e o tipo de irrigação podem beneficiar a comunidade de inimigos naturais no agroecossistema ao disponibilizar micro-habitas mais favoráveis e recursos alternativos, principalmente em períodos de baixa precipitação pluviométrica. O objetivo deste trabalho foi avaliar como o consórcio tomate + coentro e o tipo de irrigação (gotejamento e aspersão) podem beneficiar a comunidade de inimigos naturais no agroecossistema do tomateiro. O trabalho foi realizado no campo experimental da Embrapa Hortaliças, Gama, DF, de setembro a novembro de 2008. Os tomateiros foram plantados em monocultura ou consorciados com o coentro e irrigados por gotejamento e por aspersão (três repetições por tratamento), formando dois conjuntos de parcelas experimentais de acordo com o tipo de irrigação. A comunidade de inimigos naturais foi amostrada por observações diretas em 20 plantas de tomate por parcela e nas plantas de coentro sacudindo-se as plantas em cima de uma bandeja onde eram coletados os insetos. A abundância, riqueza e diversidade das espécies de inimigos naturais foram maiores nas parcelas cultivadas com coentro, independente do sistema de irrigação. Nas parcelas plantadas em monocultura foram encontradas mais espécies quando o tomateiro foi irrigado por aspersão. No entanto, a resposta de cada espécie de inimigo natural ou grupo de espécies foi distinta para o consórcio ou o tipo de irrigação. Portanto, em períodos de baixa precipitação, o consórcio tomate + coentro e a irrigação por aspersão podem favorecer a conservação de inimigos naturais no agroecossistema do tomateiro orgânico.

The adoption of cultural practices such as companion plants and the kind of irrigation system can benefit the community of natural enemies in the agroecosystem due to the increase of more favorable microhabitats available and as a source of alternative resources, mainly in periods of low precipitation. This study evaluated how the tomato + coriander intercrop and the kind of irrigation (drip and sprinkler) could benefit the community of natural enemies in the tomato agroecosystem. This work was carried out in the experimental field of Embrapa Hortaliças, Gama, DF, from September to November 2008. The tomatoes were planted in monoculture or with coriander (companion plant) and irrigated by drip and sprinkler irrigation (three replicates per treatment), forming two groups of experimental plots according to the kind of irrigation. The community of natural enemies was sampled by the direct observation of specimens on 20 tomatoes plants per plot and in the treatments. Coriander plants were shaken over a plastic tray for collection of insects. The abundance, richness and diversity of natural enemies were higher in tomato + coriander plots, regardless of the irrigation system. We observed more species of natural enemies in tomato monoculture plots when it was irrigated by sprinkler irrigation. However, the cultural practices adopted had a different effect on each species or group of species. Therefore, in periods of low precipitation, the tomato + coriander consortium associated with sprinkler irrigation can enhance the conservation of natural enemies in the organic tomato agroecosystem.