Invasive consequences of using micro-electrodes and microdialysis probes in the brain

The ability to monitor the concentration of neurotransmitters in the extracellular space of living brain is crucial to improving our understanding of the neurochemical aspects of brain function and the dysfunction associated with numerous neurological disorders. Microdialysis probes and electrochemical microsensors are often used for in-vivo neurotransmitter monitoring, but these are invasive devices that are implanted directly into brain tissue. Although the selectivity, sensitivity, and temporal resolution of these devices have been characterized in detail, less attention has been paid to the impact of the trauma that they inflict on the tissue or the effect of any such trauma on the outcome of the measurements that they are used to perform. In this paper, we describe emerging evidence that suggests trauma effects deserve closer consideration than they have received to date. (C) 2003 Published by Elsevier B.V.