Living Human Brain Slices: Network Analysis Using Voltage-Sensitive Dyes

The study of diseases of the nervous system relies heavily on the use of animal models which try to replicate the human condition via various methods. The underlying assumption is that the root causes of the impairment are similar in the animal model and the human patient, thus validating the findings in the animal model as relevant for the human condition. This assumption is difficult to verify, as experiments analogous to those being performed in the animal model obviously cannot be performed in humans. In severe cases of epilepsy and during treatment of brain tumors, surgical removal of diseased brain tissue is the last available option. The extracted tissue may be used to study the disease directly using in vitro methodology, circumventing the need for an animal model. During the surgical procedure, the epileptic “focus” is removed from the temporal lobe. The dissected tissue is usually composed of neocortex, hippocampus, and amygdala. This chapter describes the preparation of brain slices from the tissue excised during the surgery and the use of voltage-sensitive dyes to investigate network activity in the human brain slices.