Different striatal D2 -like receptor function in an early stage after unilateral striatal lesion and medial forebrain bundle lesion in rats

• Published in: Brain research 2010-03, Vol.1317, p.227-235
• Main Authors: Sun, Wei, Sugiyama, Kenji, Fang, Xin, Yamaguchi, Hiroshi, Akamine, Soichi, Magata, Yasuhiro, Namba, Hiroki
• Format: Article
• Language: English
• Subjects: Adult and adolescent clinical studies; Animals; Biological and medical sciences; Corpus Striatum - diagnostic imaging; Corpus Striatum - injuries; Corpus Striatum - metabolism; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Disease Models, Animal; Dopamine - metabolism; Dopamine Plasma Membrane Transport Proteins - metabolism; Male; Medial Forebrain Bundle - diagnostic imaging; Medial Forebrain Bundle - injuries; Medial Forebrain Bundle - metabolism; Medical sciences; Motor Activity - physiology; Neurology; Neurons - metabolism; Neuropsychological Tests; Organic mental disorders. Neuropsychology; Oxidopamine; Parkinsonian Disorders - chemically induced; Parkinsonian Disorders - metabolism; Presynaptic Terminals - metabolism; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Radionuclide Imaging; Rats; Rats, Sprague-Dawley; Receptors, Dopamine D2 - metabolism; Time Factors
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2009.12.048

Abstract Unilateral striatal lesion and complete medial forebrain bundle (MFB) lesion by 6-hydroxydopamine in rats have been widely used as Parkinson disease (PD) models. However, the difference of pre- and post-synaptic dopamine (DA) system in these two models are not well concerned. In order to investigate the pathophysiologic difference between the MFB lesion rats and striatal lesion rats, we studied the variation of pre-synaptic DA transporter and post-synaptic D2 -like receptor in nigrostriatal DA system using binding assay, behavioral test and a small animal PET. Our data showed that there was a same tendency of the striatal DA transporter decrease both in MFB lesion rats and striatal lesion rats 4 weeks after lesion, however, it showed increase (up-regulation) of D2 -like receptor in the MFB lesion rats, whereas showed decrease (down-regulation) in the striatal lesion rat. This finding strongly indicated the different dynamic pathophysiologic process between the MFB lesion model and striatal lesion model. MFB lesion model mimics an early stage of PD, whereas striatal lesion model mimics Parkinson syndrome, such as vascular Parkinson syndrome. Such difference should be taken into account in the selection of these model systems.