9 1998 by Humana Press Inc. All rights of any nature, whatsoever,reserved. 1044-7393/98/3402-3-0121 $11.00 Extensive Degeneration of Catecholarninergic Neurons to Scrapie Agent 87V in the Brains of IM Mice SEoN6-WooK YuN, 1 EuN-KYouN6 CNOI, 1 WoN-KYu Ju, 1 MYuN6-Soo AHN, 3 RICHARD I. CARP, 4 HENRYKM. WISNIEWSKI, 4 AND YONG-SUN KIM*'1'2 1Institute of Environment and Life Science; 2Department of Microbiology, 3Department of Neurosurgery, College of Medicine, Hallym University, Chunchon 200-702, Korea; and 4New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY Received January 6, 1998; Revised May 18, 1998; Accepted May 25, 1998 ABSTRACT Scrapie is a degenerative disease of the central nervous system of sheep and goats. The causative agent has been passaged to a num- ber of laboratory species, including mice and hamster. Amyloid plaque formation and vacuolation, the signs of senile dementia, are found in the brains of mice infected with 87V scrapie agent. Dopamine (DA) and norepinephrine (NE) concentrations in the brains of scrapie-infected mice were measured with high-performance liquid chromatography-electrochemical detector (HPLC-ECD). A sig- nificant decrease in NE level was exhibited in all regions tested, whereas the level of DA decreased significantly only in cerebral cortex. Imrnunohistochemistry was used to examine immunoreac- tive catecholamine neurons in substantia nigra and locus ceruleus using antisera against tyrosine hydroxylase (TH). The population of TH-immunoreactive neurons in the substantia nigra and locus ceruleus were significantly decreased in scrapie-infected mice com- pared to controls. These data suggest that both the noradrenergic and dopaminergic system are sensitive to the action of scrapie agent *Author to whom all correspondence and reprint requests should be addressed. Molecular and Chemical Neuropathology 121 Vol. 34, 1998