Estimating axon conduction velocity in vivo from microstructural MRI

Ionic mechanisms maintaining action potential conduction velocity at high firing frequencies in an unmyelinated axon

The descending contralateral movement detector (DCMD) is a high-performance interneuron in locusts with an axon capable of transmitting action potentials (AP) at more than 500 Hz. We investigated biophysical mechanisms for fidelity of high-frequency transmission in this axon. We measured conduction velocities (CVs) at room temperature during exposure to 10 mmol/L cadmium, a calcium current anta...

Estimating motion from MRI data

INVITED PAPER: Magnetic resonance imaging (MRI) is an ideal imaging modality to measure blood flow and tissue motion. It provides excellent contrast between soft tissues, and images can be acquired at positions and orientations freely defined by the user. From a temporal sequence of MR images, boundaries and edges of tissues can be tracked by image processing techniques. Additionally, MRI permi...

Conduction velocity costs energy

Hodgkin and Adrian’s 1975 hypothesis that the squid axon is optimized for maximum conduction velocity is flawed by (i) the inaccurate value of its prediction for channel density, and (ii) the prohibitive energetic expense entailed by their prediction. Here we investigate the metabolic cost of conduction velocity. By manipulating ion channel density or by manipulating the Nernst battery voltages...

Modeling collective axon growth from in vivo data reveals the importance of physical axon-axon interactions

Estimating 3D Strain from 4D Cine-MRI and Echocardiography: In-Vivo Validation

The quantitative estimation of regional cardiac deformation from 3D image sequences has important clinical implications for the assessment of myocardial viability. The validation of such image-derived estimates, however, is a non-trivial problem as it is very difficult to obtain ground truth. In this work we present an approach to validating strain estimates derived from 3D cine-Magnetic Resona...