Comparative internal anatomy of Staurozoa (Cnidaria), with functional and evolutionary inferences.

Comparative efforts to understand the body plan evolution of stalked jellyfishes are scarce. Most characters, and particularly internal anatomy, have neither been explored for the class Staurozoa, nor broadly applied in its taxonomy and classification. Recently, a molecular phylogenetic hypothesis was derived for Staurozoa, allowing for the first broad histological comparative study of staurozoan taxa. This study uses comparative histology to describe the body plans of nine staurozoan species, inferring functional and evolutionary aspects of internal morphology based on the current phylogeny of Staurozoa. We document rarely-studied structures, such as ostia between radial pockets, intertentacular lobules, gametoducts, pad-like adhesive structures, and white spots of nematocysts (the last four newly proposed putative synapomorphies for Staurozoa). Two different regions of nematogenesis are documented. This work falsifies the view that the peduncle region of stauromedusae only retains polypoid characters; metamorphosis from stauropolyp to stauromedusa occurs both at the apical region (calyx) and basal region (peduncle). Intertentacular lobules, observed previously in only a small number of species, are shown to be widespread. Similarly, gametoducts were documented in all analyzed genera, both in males and females, thereby elucidating gamete release. Finally, ostia connecting adjacent gastric radial pockets appear to be universal for Staurozoa. Detailed histological studies of medusozoan polyps and medusae are necessary to further understand the relationships between staurozoan features and those of other medusozoan cnidarians.

On the centenary of the birth of Francis H. C. Crick – from physics to genetics and neuroscience / O centenário de nascimento de Francis H.C. Crick – da física para a genética e a neurociência

ABSTRACT The year 2016 marks the centenary of the birth of Francis Crick (1916–2004), who made outstanding contributions to genetics and neuroscience. In 1953, in a collaborative study, Francis Crick and James Watson discovered the DNA double helix, and in 1962 they and Maurice Wilkins were awarded the Noble Prize in Physiology or Medicine. Crick subsequently became very interested in neuroscience, particularly consciousness and its relationship to the claustrum, a small gray matter structure between the insula and putamen.

RESUMO O ano de 2016 é o centenário de nascimento de Francis Crick (1916–2004), físico, biólogo e neurocientista, cujas contribuições para a genética e a neurociência foram magníficas. Crick, em um estudo colaborativo com Watson, descobriu a estrutura molecular do DNA (dupla hélice) em 1953, e em 1962 ambos receberam o prêmio Nobel de Fisiologia ou Medicina, junto com Wilkins. Após Crick tornou-se muito interessado na área de neurociência, particularmente no estudo da consciência, e a sua relação com o claustrum, uma pequena estrutura de substância cinzenta localizada entre a ínsula e o putame.

Subcortical connections of area V4 in the macaque.

Area V4 has numerous, topographically organized connections with multiple cortical areas, some of which are important for spatially organized visual processing, and others which seem important for spatial attention. Although the topographic organization of V4's connections with other cortical areas has been established, the detailed topography of its connections with subcortical areas is unclear. We therefore injected retrograde and anterograde tracers in different topographical regions of V4 in nine macaques to determine the organization of its subcortical connections. The injection sites included representations ranging from the fovea to far peripheral eccentricities in both the upper and lower visual fields. The topographically organized connections of V4 included bidirectional connections with four subdivisions of the pulvinar, two subdivisions of the claustrum, and the interlaminar portions of the lateral geniculate nucleus, and efferent projections to the superficial and intermediate layers of the superior colliculus, the thalamic reticular nucleus, and the caudate nucleus. All of these structures have a possible role in spatial attention. The nontopographic, or converging, connections included bidirectional connections with the lateral nucleus of the amygdala, afferent inputs from the dorsal raphe, median raphe, locus coeruleus, ventral tegmentum and nucleus basalis of Meynert, and efferent projections to the putamen. Any role of these structures in attention may be less spatially specific.