A substantial population of cells from the nucleus tegmenti pedunculopontinus was demonstrated to have descending projections to the spinal cord using fluorescent retrograde axonal tracers. Double-labeling studies showed that separate perikarya in this region have descending versus ascending projections. The distributions of the cell bodies with ascending… (More)
Motivated by EEG recordings of normal brain activity, we construct arbitrarily large McCulloch-Pitts neural networks that, without any external input, make every subset of their neurons fire in some iteration (and therefore in infinitely many iterations).
An antiserum against tubulin, NS20, was previously shown to specifically attenuate both fast axonal transport in vivo (Johnston, K. M. et al., Brain Res. 385, 38-45 (1986)) and in vitro (Johnston, K. M. et al., Cell Motil. Cytoskel. 7, 110-115 (1987)) and flagellar motility (Goldsmith, M. et al., Cell Motil. Cytoskel. 20, 249-262 (1991)). We hypothesized… (More)
Microtubules (MTs) interact with force-generating proteins to generate a variety of intracellular movements, including intracellular particle transport, ciliary-flagellar beating, and chromosome-spindle movements during mitosis-meiosis. Relatively little is known about the mechanics of these motor-MT interactions, in part because the motor binding domains… (More)
In a pioneering classic, Warren McCulloch and Walter Pitts proposed a model of the central nervous system. Motivated by EEG recordings of normal brain activity, Chvátal and Goldsmith asked whether these dynamical systems can be engineered to produce trajectories that are irregular, disorderly, and apparently unpredictable. We show that they cannot build… (More)
In a pioneering classic, Warren McCulloch and Walter Pitts proposed a model of the central nervous system; motivated by EEG recordings of normal brain activity, Chvátal and Goldsmith asked whether or not this model can be engineered to provide pseudorandom number generators. We supply evidence suggesting that the answer is negative. Electroencephalogram… (More)
The Maximal Lyapunov Exponent of a Time Series Mark Goldsmith Techniques from dynamical systems have been applied to the problem of predicting epileptic seizures since the early 90's. In particular, the computation of Lyapunov exponents from a series of electrical brain activity has been claimed to have great success. We survey the relevant topics from pure… (More)