Ascorbic acid: A useful reductant to avoid oxidation of catecholamines in electrophysiological experiments in vitro?

The actions of the reductant ascorbic acid on rat neocortical
neurons in vitro was investigated by means of intracellular
recordings. At a concentration (500 μM), which reduced the
magnitude of dopamine degradation in oxygen-saturated saline
solutions by about 50%, ascorbic acid reversibly depressed synaptic
potentials and enhanced direct excitability of cortical neurons.
The latter effect was not reversible within the observation period.
Ascorbic acid did not alter membrane potential and input resistance
of the neurons. On the basis of our results we conclude that
ascorbic acid is not a useful reductant to avoid oxidation of
catecholamines in oxygen-saturated solutions used in
electrophysiological experiments in vitro.