Cell death in the nervous system.

Programmed cell death is an important process in many types of cell. In the central nervous system of vertebrates, up to 50% of neurons die during development. The fact that in many cases neuronal cell death depends on macromolecular synthesis suggests that there is a genetic program that must be activated for cell death to occur.

More real-time visual and haptic interaction with anatomical data.

The University of Colorado's Center for Human Simulation has developed fundamental algorithms for real-time visual and haptic interaction with polygonal and voxel base data sets, including those derived from the Visible Human Dataset. These algorithms are currently being used to create prototype simulators for surgery, needle insertion (anesthesiology, radiology, and rheumatology), dentistry, and ophthalmology. This paper briefly discusses our segmentation and classification effort as well as our ability to create texture-mapped polygonal models directly from the data: both are fundamental to the creation of anatomically based simulators.

6-hydroxydopamine induces the loss of the dopaminergic phenotype in substantia nigra neurons of the rat. A possible mechanism for restoration of the nigrostriatal circuit mediated by glial cell line-derived neurotrophic factor.

Intraparenchymal injections of the neurotoxin 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle in rats destroys the dopaminergic neurons in the pars compacta of the substantia nigra. In other transmitter systems it has been found that axotomy or neurotoxin exposure produces an initial loss of neurotransmitter phenotype, with cell death occurring over a much slower time course. To determine whether this also occurs in dopamine neurons after 6-OHDA, two approaches were utilized.

Apparent apoptotic cell death in the olfactory epithelium of adult rodents: death occurs at different developmental stages.

In the olfactory epithelium of adult rodent, receptor neurons are generated continually. Despite the ongoing generation of new neurons, no corresponding increase occurs in the thickness of the mature olfactory epithelium. Thus, epithelial cell death must occur to offset the continual generation of new cells.

Expression of the death-associated gene RP-8 in granule cell neurons undergoing postnatal cell death in the cerebellum of weaver mice.

RP-8 is one of several mRNAs elevated during apoptosis in immature thymocytes. We used in situ hybridization to look for RP-8 mRNA in the cerebella of weaver mice. In the weaver mouse cerebellar granule cells fail to differentiate and instead die during the first two weeks of postnatal development [30].