Spreading depression of Leão in rodent and human cortex.

Spreading depression (SD) has been implicated in the pathophysiology of a number of neurological conditions. The same methodology was used to elicit SD in anesthetized rats and in non-anesthetized patients undergoing cortical resections for intractable epilepsy. A slowly spreading DC potential shift (mean -9 mV) occurred in the cortex of 10 of 15 rats in association with attenuation of the electrocorticogram but this could not be reproduced in any of the human cortices (n = 23) where the mean potential shift was -0.56 mV (P < 0.0001). SD is more difficult to elicit in human than rodent cortex and may not occur in man.