CHEMICAL LESION OF THE INFERIOR OLIVE REDUCES [I-125] SARCOSINE(1)-ANGIOTENSIN-II BINDING TO AT(2) RECEPTORS IN THE CEREBELLAR CORTEX OF YOUNG-RATS

Citation
O. Johren et al., CHEMICAL LESION OF THE INFERIOR OLIVE REDUCES [I-125] SARCOSINE(1)-ANGIOTENSIN-II BINDING TO AT(2) RECEPTORS IN THE CEREBELLAR CORTEX OF YOUNG-RATS, Brain research, 793(1-2), 1998, pp. 176-186
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences
Journal title
ISSN journal
0006-8993
Volume
793
Issue
1-2
Year of publication
1998
Pages
176 - 186
Database
ISI
SICI code
0006-8993(1998)793:1-2<176:CLOTIO>2.0.ZU;2-R
Abstract
In young rats, AT(2) receptors and AT(2) receptor mRNA are discretely localized in neurons of the inferior olive, with highest expression in the medial nucleus. We previously detected AT(2) receptor binding, bu t not AT(2) receptor mRNA, in the molecular layer of the cerebellar co rtex. To determine whether AT, receptors are expressed in climbing fib er terminals which arise to the molecular layer from the inferior oliv e and innervate Purkinje cells, we chemically destroyed olivary neuron s of 2-week-old rats by intraperitoneal (i.p.) injection of the neurot oxin 3-acetylpyridine. Lesions of the inferior olive reduced [I-125]Sa r(1)-Ang II binding to AT(2) receptors and AT(2) receptor mRNA levels in this area by 50%, and produced a similar decrease in AT(2) receptor binding in the molecular layer of the cerebellar cortex. The extent o f binding reduction was similar 3 days and 7 days after the lesion. 3- Acetylpyridine lesions did not change [I-125]Sar(1)-Ang II binding to AT(1) receptors in the molecular layer of the cerebellar cortex or AT( 1) receptor mRNA levels in Purkinje cells. AT(2) receptor binding and AT(2) receptor mRNA levels in the deep cerebellar nuclei were also not affected by 3-acetylpyridine. Our results support the hypothesis that AT(2) receptors are produced by inferior olivary neurons and transpor ted through climbing fibers to the molecular layer of the cerebellar c ortex. The high expression of AT(2) receptors in the inferior olivary- cerebellar pathway during a crucial time in postnatal development of c limbing fiber-Purkinie cell connectivity suggest a role of AT(2) recep tors in the development of this pathway. (C) 1998 Elsevier Science B.V . All rights reserved.