Epilepsy often develops after the brain is damaged, and patients commonly must take anticonvulsant drugs for a lifetime despite unpleasant side effects.
The battlefield can be a laboratory for assessing response of the human body to stress.
Marine threespine sticklebacks haven't morphologically changed in an estimated 10 million years, but their freshwater offshoots show no signs of slowing down. These 5-cm-long, freshwater fish have undergone a recent evolutionary change, variably losing their calcified body armor and retractable pelvic and dorsal spines. Remarkably, isolated marine and freshwater sticklebacks can be hybridized in the laboratory, a fact that is allowing researchers to analyze the genetics behind their natural dive
Courtesy of Martin ChaplinWater molecules cluster to form hydrogen-bonded bicyclo-octamers (H2O)8 (top left) that can link together into larger structures (top right). Ideally they form 280-member icosahedral clusters, (H2O)280, (below), shown looking down the two-fold, three-fold, and five-fold axes of symmetry. Only the oxygen atoms of the constituent water molecules are shown (except at top left).Researchers are beginning to glimpse water's secret social life. Evidence is mounting that water
HALF FULL, HALF EMPTY, OR ...© 2004 AAASAfter each neurotransmitter release, MK801, an open-channel blocker that can only block a channel that has been activated, decreases initial current (which has been normalized for wild type and mutant cells). In the colocalization model, VGLUT1 and VGLUT2 occupy the same vesicles filling them partially. The commingling model proposes that transporters occupy distinct vesicles in the same synapse. The segregation model proposes that the transporters ar
USE IT OR LOSE IT:© 2004 AAASIn A, a 40-day-old mouse in which one nostril was cauterized at birth shows a single X-gal stained M71 glomerulus at the half bulb corresponding with the open nostril (bulbO). In B, two glomeruli appear in the half bulb corresponding to the closed nostril (bulbX) – a seeming sign of immaturity. In the graphs C and D, the critical period for glomerulus maturation appears longer for M71 than for the closely related odorant receptor M72.A smell can conjure in
VISUALIZING VESICLES:© 2003 Nature Publishing GroupIn A, researchers used a fluorescent protein (synaptopHluorin) to visualize synaptic vesicle movement. Some vesicles stay open briefly before retrieval (kiss-and-run). Others stay open longer but also don't collapse fully into the plasma membrane (compensatory). Still others collapse and are not retrieved until another stimulus is delivered (stranded). In B, another group used a dye FM1-43, to study vesicle retrieval and found that single v
CILIA FOR ASYMMETRY:Courtesy of Joseph R. Marszalek and Lawrence S.B. GoldsteinCilia from a mouse embryo found on the embryonic node. Researchers have shown that embryos without the genes encoding motor subunits for such cilia develop defects in left-right body asymmetry determination.Most biologists are familiar with motile cilia, the finger-like appendages that allow unicellular organisms to swim, and the specialized cells that move fluids and clear away debris in our kidneys and lungs. Few ar
MUTAGENS AND MITOSIS:Courtesy of Thea GoepfertSection cut through the mammary gland of a rat that had been treated with the carcinogen MNU. Centrosomes (green) are arranged at the base of each nucleus (red), and 45% of cells show amplified chromosomes.Comments from journal article reviewers often surprise or frusrate. But the reviewer response that cell biologist William Brinkley received six years ago left him stunned.Brinkley and his collaborator, Subrata Sen at the University of Texas M.D. An
Erica P. JohnsonA biomolecular 'piston' derived from viral peptides should respond to changes in pH.Engineers expect that tomorrow's nanomachines – biomolecular devices that might patrol cells, repair genes, scour out infections, and haul away debris – will be powered by nature's own motors: the proteins kinesin, myosin, and dynein, which turn adenosine triphosphate (ATP) into fuel and move loads along microtubular tracks of actin and tubulin.It makes sense to use these off-the-shelf