PHYSIOLOGICAL FACTORS INFLUENCING BRAIN GLYCOGEN OF THE MOUSE

Abstract

SUMMARY 1. Following the demonstration [Chance & Yaxley, 1950] that the brain glycogen of the mouse rises during a convulsion, an attempt has been made to study the effect of various substances on the level of brain glycogen in the mouse both when resting and after a convulsion induced by metrazol. The substances used were glucose, adrenaline, insulin, deoxycorticosterone glucoside, cortisone acetate and the anti-insulin principle of the anterior pituitary. The effect of fasting on the brain glycogen of the resting mouse was also examined. 2. The level of glycogen in the brain rose in the presence of a raised blood sugar or following injection of the anti-insulin principle. Insulin antagonized the effect of the latter without altering the level of the blood sugar. 3. During convulsions induced by metrazol after the administration of insulin, the level of the blood-sugar was reduced, and the usual increment in brain glycogen was suppressed. It reappeared when sufficient glucose was injected to restore the blood-sugar level to normal. None of the other substances tested affected the rise in glycogen level of the brain induced by a convulsion. 4. During certain types of normal behaviour [Chance, 1953 a] the levels of the blood sugar and brain glycogen generally change independently of each other, but on occasion both rise simultaneously. It is concluded that they represent independent responses resulting from central nervous activity.