The Experts below are selected from a list of 2352 Experts worldwide ranked by ideXlab platform

Christophe H Sotak - One of the best experts on this subject based on the ideXlab platform.

  • Spreading waves of decreased diffusion coefficient after Cortical stimulation in the rat brain
    Magnetic Resonance in Medicine, 1994
    Co-Authors: Lawrence L Latou, Yasuhiro Hasegawa, James E Formato, Marc Fishe, Christophe H Sotak
    Abstract:

    A method is demonstrated for the noninvasive detection and study of Spreading Cortical Depression. Spreading Depression (SD) was elicited in rats by topical application of potassium chloride to the exposed cortex. The apparent diffusion coefficient (Dapp) of water in a region of the cortex, measured using a PFG-NMR spin echo sequence with an observation time of 40 ms, declines 35% within 30 s and recovers to the normal value within the next 30 s. The region of decreased Dapp was shown to be 2 mm in size and to move in the cortex, away from the point of application, with a uniform velocity of 3.3 +/- 0.5 mm/min. The behavior of the affected region is consistent with other reports of the behavior of SD as monitored by electrophysiological means. The technique can be implemented on currently available MRI equipment and makes possible the noninvasive study of SD in animal models of neurological disorders, their therapeutic intervention, and possibly the study of SD in humans.

Yoshio Okada - One of the best experts on this subject based on the ideXlab platform.

  • analysis of meg signals of Spreading Cortical Depression with propagation constrained to a rectangular Cortical strip ii gyrencephalic swine model
    Brain Research, 1999
    Co-Authors: Susan M Bowyer, Norman Tepley, Nicholas Papuashvili, Seiya Kato, Gregory L Barkley, K M A Welch, Yoshio Okada
    Abstract:

    Currents produced during Spreading Cortical Depression (SCD) in a gyrencephalic species (swine) were studied with magnetoencephalography (MEG) and electrocorticography (ECoG). SCD, initiated using electrical stimulation of the cortex, was constrained to propagate within a rectangular Cortical strip in order to simplify the interpretation of the underlying currents. The ECoG signals monitored along the strip revealed that SCD propagated from an initiation site on the gyrus at a rate of 7.9+/-3.2 mm/min (n=23), entered the deep coronal sulcus and in most cases emerged from the other side of the sulcus, continuing to propagate across the next gyrus at a rate of 5.9+/-2.7 mm/min (n=22). The apparent propagation velocity within the sulcus was reduced to 1.7+/-0.8 mm/min (n=21). Strong MEG signals were observed as SCD entered the sulcus. The direction of magnetic field was opposite for SCD's on opposite banks of the sulcus. The currents were directed from a superficial layer to deeper layers of the cortex. The characteristics of SCD and associated MEG patterns from a gyrencephalic species may be similar to those in human patients during migraine aura.

Norman Tepley - One of the best experts on this subject based on the ideXlab platform.

  • analysis of meg signals of Spreading Cortical Depression with propagation constrained to a rectangular Cortical strip ii gyrencephalic swine model
    Brain Research, 1999
    Co-Authors: Susan M Bowyer, Norman Tepley, Nicholas Papuashvili, Seiya Kato, Gregory L Barkley, K M A Welch, Yoshio Okada
    Abstract:

    Currents produced during Spreading Cortical Depression (SCD) in a gyrencephalic species (swine) were studied with magnetoencephalography (MEG) and electrocorticography (ECoG). SCD, initiated using electrical stimulation of the cortex, was constrained to propagate within a rectangular Cortical strip in order to simplify the interpretation of the underlying currents. The ECoG signals monitored along the strip revealed that SCD propagated from an initiation site on the gyrus at a rate of 7.9+/-3.2 mm/min (n=23), entered the deep coronal sulcus and in most cases emerged from the other side of the sulcus, continuing to propagate across the next gyrus at a rate of 5.9+/-2.7 mm/min (n=22). The apparent propagation velocity within the sulcus was reduced to 1.7+/-0.8 mm/min (n=21). Strong MEG signals were observed as SCD entered the sulcus. The direction of magnetic field was opposite for SCD's on opposite banks of the sulcus. The currents were directed from a superficial layer to deeper layers of the cortex. The characteristics of SCD and associated MEG patterns from a gyrencephalic species may be similar to those in human patients during migraine aura.

Susan M Bowyer - One of the best experts on this subject based on the ideXlab platform.

  • analysis of meg signals of Spreading Cortical Depression with propagation constrained to a rectangular Cortical strip ii gyrencephalic swine model
    Brain Research, 1999
    Co-Authors: Susan M Bowyer, Norman Tepley, Nicholas Papuashvili, Seiya Kato, Gregory L Barkley, K M A Welch, Yoshio Okada
    Abstract:

    Currents produced during Spreading Cortical Depression (SCD) in a gyrencephalic species (swine) were studied with magnetoencephalography (MEG) and electrocorticography (ECoG). SCD, initiated using electrical stimulation of the cortex, was constrained to propagate within a rectangular Cortical strip in order to simplify the interpretation of the underlying currents. The ECoG signals monitored along the strip revealed that SCD propagated from an initiation site on the gyrus at a rate of 7.9+/-3.2 mm/min (n=23), entered the deep coronal sulcus and in most cases emerged from the other side of the sulcus, continuing to propagate across the next gyrus at a rate of 5.9+/-2.7 mm/min (n=22). The apparent propagation velocity within the sulcus was reduced to 1.7+/-0.8 mm/min (n=21). Strong MEG signals were observed as SCD entered the sulcus. The direction of magnetic field was opposite for SCD's on opposite banks of the sulcus. The currents were directed from a superficial layer to deeper layers of the cortex. The characteristics of SCD and associated MEG patterns from a gyrencephalic species may be similar to those in human patients during migraine aura.

Daniel C Beard - One of the best experts on this subject based on the ideXlab platform.