EEG development in normal and undernourished rats.

The development of EEG was studied in normal and undernourished white and black hooded rats, aged 9-30 days. Undernutrition of the young was accomplished by underfeeding the mothers with restricted amounts of a standard laboratory food from the 7th day after conception until the 21st day after birth. Bipolar EEG recordings were made from the sensorimotor cortex and from the visual cortex in rats with chronically implanted electrodes. The EEG was recorded, stored on magnetic tape and analyzed for amplitude distributions and frequency spectra. During the recording 3 behavioural states (defined on the basis of behavioural criteria) were distinguished.