Metabolic and electrophysiological alterations in an animal model of neocortical neuronal migration disorder

Cortical migration disorders are a major cause for intractable epilepsy syn dromes. High resolution MRI and PET are increasingly capable to identify co rtical dysgenesis. In this study we used the rat freeze lesion model to inv estigate cortical morphological and functional changes in adult rats after induction of a cortical freeze lesion at postnatal day (p) 0. Autoradiograp hic measurements of basic cortical [C-14]-deoxyglucose metabolism showed a significant reduction up to 1 mm lateral to the lesion but no remote change s. Electrophysiological in vitro recordings revealed a significant reductio n in the amplitude of stimulus-evoked field potential responses recorded la teral to the lesion as compared to medial recording sites. Our data provide further evidence that spatially restricted developmental alterations of co rtical morphology cause functional changes in surrounding and histologicall y normal areas that need to be considered for a better understanding of the resulting pathophysiology. NeuroReport 12:2001-2006 (C) 2001 Lippincott Wi lliams & Wilkins.