Neuroreport
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Comparative Study
Topiramate inhibits cortical spreading depression in rat and cat: impact in migraine aura.
Cortical spreading depression is thought to be the pathophysiological correlate of the neurological symptoms in migraine with aura. Topiramate is an anti-epileptic drug that is also used as a migraine preventive. ⋯ Topiramate at 30 mg kg(-1) was able to inhibit regional cerebral blood flow changes and cortical depolarization and spreading depression in all rats, and in 8 of 13 cats. We conclude that topiramate may act on mechanisms involved in the initiation and propagation of spreading depression, and that these mechanisms may be similar to those involved in the therapeutic role.
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Comparative Study
Geometric visual illusions in microgravity during parabolic flight.
This investigation explores whether the absence of gravitational information in a microgravity environment affects the perception of several classical visual illusions based on the arrangement of horizontal and vertical lines. Because the perception of horizontal and vertical orientation changes in microgravity, our prediction was that the strength of visual illusions based on the arrangement of horizontal and vertical lines would be altered when study participants were free-floating during parabolic flight. ⋯ Because the former illusions rely more heavily on perspective cues for generating inaccurate judgments of depth and size, these results suggest an alteration in the role of linear perspective for three-dimensional vision in microgravity. They also confirm that the visual system normally relies on otolith and somatosensory information for providing accurate judgments about the size and distance of objects when presented with planar presentations of geometric figures.