PT  - JOURNAL ARTICLE
AU  - G. K. Aghajanian
AU  - F. E. Bloom
TI  - ELECTRON-MICROSCOPIC LOCALIZATION OF TRITIATED NOREPINEPHRINE IN RAT BRAIN: EFFECT OF DRUGS
DP  - 1967 Jun 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 407--416
VI  - 156
IP  - 3
4099  - http://jpet.aspetjournals.org/content/156/3/407.short
4100  - http://jpet.aspetjournals.org/content/156/3/407.full
SO  - J Pharmacol Exp Ther1967 Jun 01; 156
AB  - The cellular localization of tritiated norepinephrine (H3-NE) injected into the cerebral ventricular system was studied by electron-microscopic autoradiography. The distribution of autoradiographic grains in control and drug-pretreated (reserpine and desmethylimipramine) animals was compared. In the controls, intraventricular injection of H3-NE resulted in intense autoradiographic activity over nerve endings and axons in the hypothalamus and caudate nucleus. Hypothalamic endings with autoradiographic activity also usually contained some dense-core (granular) vesicles. Reserpine (2 mg/kg i.v.) given 2 hr prior to the H3-NE almost completely abolished the autoradiographic activity. However, the dense-core vesicles were unchanged in number or electron density. Forty-eight hours after reserpine treatment there was considerable recovery of the ability of endings to retain the H3-NE and the pattern of localization of autoradiographic activity was almost identical to the controls. For example, in the hypothalamus, grains were again over endings with dense-core vesicles. Pretreatment with desmethylimipramine (20 mg/kg) also did not alter the normal cellular patterns of localization. These results suggest that certain nerve endings (e.g., in hypothalamus and caudate) can accumulate the H3-NE given via the ventricular route. The rapid return in the ability of nerve endings to retain H3-NE 48 hr after reserpine is correlated with gross behavioral recovery. © 1967 by The Williams & Wilkins Company