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Isolated neurons from adult central ganglia of the snail Helisoma were cultured in vitro in modified Liebowitz L-15 medium. Such neurons displayed electrical excitability comparable to that in acutely dissected ganglia. Isolated neurons remained spherical in defined medium throughout culture durations up to 2 weeks. This static morphology was contrasted by(More)
Considerable evidence supports a Ca(2+) dysregulation hypothesis of brain aging and Alzheimer's disease. However, it is still not known whether (1) intracellular [Ca(2+)](i) is altered in aged brain neurons during synaptically activated neuronal activity; (2) altered [Ca(2+)](i) is directly correlated with impaired neuronal plasticity; or (3) the previously(More)
Spatial data mining, i.e., mining knowledge from large amounts of spatial data, is a demanding eld since huge amounts of spatial data have been collected in various applications, ranging from remote sensing to geographical information systems (GIS), computer cartogra-phy, environmental assessment and planning. The collected data far exceed people's ability(More)
We describe a means of visualizing the same neuron in the superior cervical ganglion of young adult mice over intervals of up to 3 months. The dendrites of these neurons change during this interval; some branches retract, others elongate, and still others appear to form de novo. Thus, neuronal dendrites in this part of the nervous system are subject to(More)
A major obstacle to understanding the mechanism of long-term change in the vertebrate nervous system has been the inability to observe the same nerve cell at different times during the life of an animal. The possibility that changes in neural connectivity underlie the remarkable flexibility of the nervous systems of mammals has therefore not been tested by(More)
Identified neurons of the snail, Helisoma, undergo extensive remodeling in response to axotomy, including the formation of specific sets of novel electrical connections. This communication addresses the question of why, under the conditions employed, some neurons readily form new connections with a single "test" neurons, whereas others do not. The present(More)
Our previous experiments have suggested the hypothesis that conjoint active neuronal outgrowth may be necessary for formation of new electrical synapses between identified neurons of adult Helisoma buccal ganglia. This growth dependence hypothesis now has been tested by examining the responses of individual pairs of neurons in isolation from the influences(More)
The explosive growth of on-line communication, in particular e-mail communication, makes it necessary to organize the information for faster and easier processing and searching. Storing e-mail messages into hierarchically organized folders, where each folder corresponds to a separate topic, has proven to be very useful. Previous approaches to this problem(More)