INCREASE OF CATECHOLAMINE CONTENT IN THE EXTRACELLULAR-SPACE OF THE RATS BRAIN CORTEX DURING SPREADING DEPRESSION WAVE AS DETERMINED BY VOLTAMMETRY

The effect of chemically initiated (KCl) spreading cortical depression on catecholamine content in the extracellular cortical space was exam ined using voltammetry technique in chloralhydrate-anaesthetized rats. Correlation between alterations in catechol-oxidative current (CA.OC) and the time-course of the slow potential (SP) change (one of the chi ef features of the spreading depression) showed that spreading depress ion wave was accompanied by the significant increase in CA.OC content (up to 158 +/- 43%, mean +/- S.D., P < 0.001). The rise of the negativ e SP preceded significant CA.OC increase by 20 +/- 8 s. This fact prov ides the evidence that catecholamine overflow cannot participate in tr iggering spreading depression wave; nevertheless it can be an importan t link of the spreading depression mechanism.