Ann M. Castelfranco

Learn More
Children in the first weeks of independent locomotion display a wide variety of walking forms. The walking forms differ in mechanical strategy and concern with balance. Three extreme walking forms are presented: the Twister, who uses trunk twist, the Faller, who uses gravity, and the Stepper, who remains balanced as much as possible. Each walking form is(More)
Significant error is made by using a point voltage clamp to measure active ionic current properties in poorly space-clamped cells. This can even occur when there are no obvious signs of poor spatial control. We evaluated this error for experiments that employ an isochronal I(V) approach to analyzing clamp currents. Simulated voltage clamp experiments were(More)
Multilayered, lipid-rich myelin increases nerve impulse conduction velocity, contributes to compact nervous systems, and reduces metabolic costs of neural activity. Based on the hypothesis that increased impulse conduction velocity provides a selective advantage that drives the evolution of myelin, we simulated a sequence of plausible intermediate stages of(More)
This paper reports a theoretical analysis of the transformation from a tactile stimulus of the face to climbing fiber responses in three regions of the cat cerebellum. The database consisted of climbing fiber receptive fields on the face from 75 responses from the anterior lobe, 33 responses from the paramedian lobule (PML), and 52 responses from the crus(More)
The ability to correct parameters of voltage-gated conductances measured under poor spatial control by point voltage clamp could rescue much flawed experimental data. We explore a strategy for correcting errors in experiments that employs a full-trace approach to parameter determination. Simulated soma voltage-clamp runs are made on a model neuron with a(More)
Almost 90 years ago, Lillie reported that rapid saltatory conduction arose in an iron wire model of nerve impulse propagation when he covered the wire with insulating sections of glass tubing equivalent to myelinated internodes. This led to his suggestion of a similar mechanism explaining rapid conduction in myelinated nerve. In both their evolution and(More)
The ability to correct parameters of voltage-gated conductances measured under poor spatial control by a point voltage clamp could rescue much awed experimental data, but requires a detailed understanding of errors caused by poor space clamp. We evaluated errors in simulated voltage-clamp experiments on a soma with a single (0:5) cylindrical process having(More)
Despite the medical urgency presented by cubozoan envenomations, ineffective and contradictory first-aid management recommendations persist. A critical barrier to progress has been the lack of readily available and reproducible envenomation assays that (1) recapitulate live-tentacle stings; (2) allow quantitation and imaging of cnidae discharge; (3) allow(More)
Rapid conduction of nerve impulses is a priority for organisms needing to react quickly to events in their environment. While myelin may be viewed as the crowning innovation bringing about rapid conduction, the evolution of rapid communication mechanisms, including those refined and enhanced in the evolution of myelin, has much deeper roots. In this review,(More)
  • 1