Becker, Klaus; Eder, Matthias; Ranft, Andreas; Meyer, Ludwig von; Zieglgänsberger, Walter; Kochs, Eberhard; Dodt, Hans-Ulrich
Low dose isoflurane exerts opposing effects on neuronal network excitability in neocortex and hippocampus.
In: PloS one
The anesthetic excitement phase occurring during induction of anesthesia with volatile anesthetics is a well-known phenomenon in clinical practice. However, the physiological mechanisms underlying anesthetic-induced excitation are still unclear. Here we provide evidence from in vitro experiments performed on rat brain slices that the general anesthetic isoflurane at a concentration of about 0.1 mM can enhance neuronal network excitability in the hippocampus, while simultaneously reducing it in the neocortex. In contrast, isoflurane tissue concentrations above 0.3 mM expectedly caused a pronounced reduction in both brain regions. Neuronal network excitability was assessed by combining simultaneous multisite stimulation via a multielectrode array with recording intrinsic optical signals as a measure of neuronal population activity.