■ Real-time measurement of free radical production using specific electrochemical sensors: new insight into the consequences of O 2 - and NO flux

Direct real-time electrochemical measurements have offered new insight into the importance of free radical interplay in a number of cellular models. Initially the interrelationship between O 2 - and NO generation in astrocytic, neuronal and mixed astrocytic/neuronal cell populations was examined. Results indicated a novel function for astrocytic nitric oxide synthase (cNOS) in regulating extracellular O 2 - production on rat astrocytes was assessed. Findings show that extracellular O 2 - generation initiated the production of NO by glial cells. Other findings facilitated by electrochemical measurements included the characterisation of a novel motor neuron like cell line for its ability to produce O 2 - and NO in response to extracellular glutamate and AMPA, the interaction of O 2 - with NO in an animal models of migraine headache and the modulatory effect of α-melanocyte stimulating hormone (α-MSH) on NO production by human epidermal melanocytes.