Radial components of the optic nerve of the mouse were studied by using thin sections and freeze-fracture replicas. The investigations were performed on normal optic nerves, as well as on those undergoing Wallerian degeneration following eyeball enucleation. Normal radial components in thin sections were observed as a series of light lines composed of small electron-lucent dots situated in the ...

Random dot kinematograms were used to simulate radial, rotational and spiral optic flow. The stimuli were designed so that, while dot speed increased linearly with distance from the centre of the display, the density of dots remained uniform throughout their presentation. In two experiments, subjects were required to perform a temporal 2AFC speed discrimination task. Experiment 1 measured the p...

The normal retinotectal path in the diencephalon of Xenopus tadpoles is widely distributed in the form of a wedge of fibres extending from the central grey to the outer margin of the diencephalon. Regenerating optic nerve fibres were shown, by silver-staining and proline autoradiography, to follow an abnormal path up the extreme lateral edge of the diencephalon. Study of tadpoles at various sta...

Registering images of a deforming surface is a well-studied problem. Solutions include computing optic flow or estimating a parameterized motion model. In the case of optic flow it is necessary to include some regularization. We propose an approach based on representing the induced transformation between images using Radial Basis Functions (RBF). The approach can be viewed as a direct, i.e. int...

A long-standing question is how fiber pathways in the mammalian CNS project to both sides of the brain. Static and real-time analyses of dye-labeled retinal axons (Godement et al., 1990, 1994) have demonstrated that at embryonic day 15-17 in the mouse, crossed and uncrossed axons from each eye diverge in a zone 100-200 microns proximal to the midline of the optic chiasm. In this study, we ident...

The trigeminal mesencephalic nucleus was studied with an electron microscope after neurotomy of the third division of the trigeminal nerve in rats. Neuronal ultrastructures were characterized by the changes of the cell organelles 17hrs after neurotomy. Especially numerous polysomes appeared in the perinuclear area and then migrated into the peripheral area. Concomitantly, the central area of th...

To investigate the role of MR imaging in wallerian degeneration, a series of animal models of increasingly complex peripheral nerve injury were studied by in vivo MR. Proximal tibial nerves in brown Norway rats were either crushed, transected (neurotomy), or transected and grafted with Lewis rat (allograft) or brown Norway (isograft) donor nerves. The nerves distal to the site of injury were im...

The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets i...