A simple integrator to process the electroencephalogram of small laboratory animals

A simple integrator to process the EEG of small laboratory animals is described. This device simultaneously integrates, at fixed short intervals, average wave frequency (SF) and wave area (SA, in microV X sec), assumed as a simplified index of the actual EEG power. From these values the average wave area, SA/SF, i.e., the quantal component of SA is calculated. By measuring the average wave frequency and by calculating SA/SF, different conditions, such as arousal reaction, drug-induced EEG activation, seizures, and anesthesia can be easily distinguished and quantified. Moreover, this approach allows one to correlate the fundamental EEG parameters (wave frequency and SA/SF) with neurochemical signs of brain activity, such as the release of neurotransmitters from the brain. Thus, a more complete knowledge of the pharmacological profile of neuroactive compounds is made possible.