THIS image by Dominik Paquet of Ludwig-Maximilians-Universität in Munich is one of the winners of the 2009 Nikon Small World Photomicrography competition. It's a confocal fluoresence microscopy image of zebrafish larvae expressing a mutant form of human Tau protein, which forms the neurofibrillary tangles that are a pathological hallmark of Alzheimer's Disease. The work is described in this recent paper.
Below are two more images from the competition.
This image of pyramidal cells in the mouse cerebral cortex was created by Celine Plachez of the University of Maryland School of Medicine. These are among the largest in the mammalian brain. First discovered by the great Spanish neuroanatomist Santiago Ramón y Cajal, they are so called because of their characteristic triangular cell body. Pyramidal cells are the brain's projection neurons, with axons that extend long distances. Most project from one region of the brain to another, and those in the motor cortex descend in the spinal cord to form connections with the neurons which control voluntary movement.
Finally, there's this image of Purkinje cells in the mouse cerebellum, by Alan Opsahl of Pfizer. These are also among the largest cells in the brain. They have a planar, or two-dimensional, structure, with an extensive dendritic tree that forms synapses with hundreds of thousands of parallel fibres, and an axon which projects down into the deep cerebellar nuclei. The information propagated along their axons is related to motor co-ordination and fine control of movement, is the sole output of the cerebellum.
Life Science
Comments (4)
Beautiful imaging, and, in the fish model, an innovative way of identifying the affected subjects. However, Alzheimer's shows not in young people, but in old age. When one peruses the paper it is shown that the symptoms begin in larval fish, not in mature ones. Is this a valid model in which to test drugs after all? It seems that the genetic manipulation has turned Alzheimer's from a disease of old age into a developmental disability.
Now, back in the dark ages (about 20 years ago) when I was working with folks who were developmentally disabled, there was a connection noted between Down's Syndrome and Alzheimer's Disease; more than 50% of the folks with non-mosaic Down's who survived past, say, 45 or so would get Alzheimer's, and their prognoses were especially grim. Perhaps these folks with the fish have once more found that connection inadvertently.
Posted by: E Wolke | October 9, 2009 1:36 PM