A new class of anti-obesity drugs that suppresses appetite by blocking cannabinoid receptors in the brain could also suppress the adaptive rewiring of the brain necessary for neural development in children, studies with mice have indicated. One such drug, rimonabant (trade name Acomplia) has been developed by Sanofi-Aventis and is awaiting approval for use in the U.S., and other pharmaceutical companies are developing similar drugs.

One of the major scientific questions about the brain is how it can translate the simple intent to perform an action—say, reach for a glass—into the dynamic, coordinated symphony of muscle movements required for that action. The neural instructions for such actions originate in the brain’s primary motor cortex, and the puzzle has been whether the neurons in this region encode the details of individual muscle activities or the high-level commands that govern kinetics—the direction and velocity of desired movements.

Using ingenious molecular espionage, scientists have found how a single key enzyme, seemingly the Swiss army knife in HIV's toolbox, differentiates and dynamically binds both DNA and RNA as part of the virus' fierce attack on host cells. The work is described this week in the journal Nature.

St. Jude Children's Research Hospital investigators have found that an electrically powered amplification mechanism in the cochlea of the ear is critical to the acute hearing of humans and other mammals. The findings will enable better understanding of how hearing loss can result from malfunction of this amplification machinery due to genetic mutation or overdose of drugs such as aspirin.

Retinas in newborn mice appear perfectly fine without any help from tiny bits of genetic material called microRNAs except for one thing — the retinas do not work.

Prions, the infamous agents behind mad cow disease and its human variation, Creutzfeldt-Jakob Disease, also have a helpful side. According to new findings from Gerald Zamponi and colleagues, normally functioning prions prevent neurons from working themselves to death. The findings appear in the May 5th issue of the Journal of Cell Biology.

Male seagulls may be more vulnerable to their environment during embryonic development than females, according to Maria Bogdanova and Ruedi Nager from the University of Glasgow in the UK. Until now, the sex differences in developmental rate and susceptibility to unfavorable conditions during the embryonic stage in birds have received little attention. The paper (1) has just been published in Springer’s journal, Behavioral Ecology and Sociobiology.

Genome Research is publishing several papers related to analyses of the duck-billed platypus (Ornithorhynchus anatinus) genome sequence. The place of (egg-laying) monotremes, such as the platypus, in mammalian evolutionary history has remained controversial. Now, researchers are finding that the distinctive anatomical and physiological properties of the platypus are reflected in the newly sequenced platypus genome. Through comparative genomics, the platypus genome is providing remarkable insights into the evolution of venom components, the sex-determination system, testicular descent, and small RNA pathways. Primary research reports describing these novel insights will appear online May 8, concurrent with publication of the platypus genome sequence report in the journal Nature.

The genome of a newly-emerging superbug, commonly known as Steno, has just been sequenced. The results reveal an organism with a remarkable capacity for drug resistance. The research was carried out by scientists at the Wellcome Trust Sanger Institute near Cambridge and the University of Bristol.