1. The changes in the glycogen content of different parts of the brain have been studied in mice in relation to the behaviour of these animals.
2. Increases in glycogen content have been demonstrated after a jump, a fall, after the righting reaction accompanying a fall, and after aggressive behaviour has been shown in a fight.
3. No increase has been demonstrated during sleep, after running or walking, or after defensive behaviour in a fight.
4. It was shown earlier that external stimulation must reach convulsive intensity to produce an increase in brain glycogen, and it is suggested that the particular forms of normal behaviour associated with increase in brain glycogen involve a ‘convulsive’ type of brain activity.
‘Convulsive’ in this context may mean either a disturbance of the metabolism in some or all of the brain cells, or alternatively the mobilization of cell populations for simultaneous, and probably rapid, discharge. At present there is no evidence to suggest whether either or both of these possibilities are involved.