University of Hertfordshire

From the same journal

By the same authors

Documents

View graph of relations
Original languageEnglish
Pages (from-to)1493-1505
JournalJournal of Neural Transmission
Volume121
Issue12
Early online date30 Apr 2014
DOIs
Publication statusPublished - 1 Dec 2014

Abstract

In Parkinson's disease (PD), destruction of noradrenergic neurons in the locus coeruleus (LC) may precede damage to nigral cells and subsequently exaggerate dopaminergic cell loss. We examine if destruction of the locus coeruleus with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) alters dopaminergic cell loss in substantia nigra (SN) initiated by lipopolysaccharide (LPS) in the rat through an effect on glial cell activation. In rats, a single intraperitoneal dose of DSP-4 administered 8 days previously, caused a marked loss of tyrosine hydroxylase positive neurons in LC but no change in dopaminergic cell number in SN. Unilateral nigral LPS administration resulted in marked dopaminergic cell death with reactive microgliosis associated with enhanced p47 phox in OX-6 and OX-42 positive microglia. There was proliferation of inducible nitric oxide synthase (iNOS)-positive cells, formation of 3-nitrotyrosine (3-NT) and proliferation of astrocytes that expressed glial cell line-derived neurotrophic factor (GDNF). Following combined DSP-4 treatment and subsequent administration of LPS, unexpectedly, no further loss of tyrosine hydroxylase (TH)-immunoreactivity (-ir) occurred in the SN compared to the effects of LPS alone. However, there was a marked alteration in the morphology of microglial cell and a reduction of 3-NT- and iNOS-ir was evident. Expression of p47 phox was downregulated in microglia but up-regulated in TH-ir neurons. No further change in GFAP-ir was observed compared to that produced by DSP-4 alone or LPS alone, but the expression of GDNF was markedly reduced. This study suggests that in contrast to previous reports, prior LC damage does not influence subsequent nigral dopaminergic cell degeneration induced by LPS. Rather it appears to attenuate the microglial response thought to contribute to disease progression in PD.

Notes

This is the accepted version of the following article: Mahmoud M. Iravani, Mona Sadeghian, Sarah Rose and Peter Jenner, “Loss of locus coeruleus noradrenergic neurons alters the inflammatory response to LPS in substantia nigra but does not affect nigral cell loss”, Journal of Neural Transmission, Vol. 121(12): 1493-1505, first published online 30 April 2014. The version of record is available online via doi: 10.1007/s00702-014-1223-1. © Springer-Verlag Wien 2014

ID: 7414009