Brain Norepinephrine and Behavior A Behavioral and Kinetic Study

The behavioral effects induced by the injection of Z-norepinephrine into the cis-terna magna of dogs have been examined. As an aid to understanding the be-havioral shifts observed, the over-all fate of di-norepinephine-H3 injected via this route was followed through time, and kinetic models were constructed which ade-quately describe the level of the isotope in cerebrospinal fluid and blood. These models suggest that approximately 71 % of c/Z-norepinephrine-H3 injected into the cisterna magna enters the peripheral circulation and hence raise the strong possi-bility that the initial behavioral changes have a peripheral component. Relation-ships between behavioral changes and levels of brain norepinephrine several hours following injection are discussed. A N 1904 Weber18 noted that epinephrine injected intraspinally produced analgesia. Many subsequent reports7 ' 0.12.1s- " indi-cate that when epinephrine is injected either into the cisterna magna, cerebral ventricles, or intravenously, behavioral effects ranging from arousal to stupor are observed, depending upon the dosage used. Mannarino et al.13 recov-ered radioactivity in the major metabo-lites of norepinephrine (NE) following intraventricular injection of NE-C14. Maas and Landis14 found that, following injec-tion of NE-H3 into the cisterna magn