Effects of unilateral 6-hydroxydopamine lesions on neuropeptide immunoreactivity in the basal ganglia of the common marmoset, Callithrix jacchus, a quantitative immunohistochemical analysis.
Previous immunocytochemical studies in rats have indicated that striatal dopamine depletion leads to an increase in enkephalin-immunoreactivity and a decrease in substance P-immunoreactivity in the striatum. Similar studies in primates have lead to contradictory results. In the present study changes in tyrosine hydroxylase-, met-enkephalin- and substance P-immunoreactivity were determined in the basal ganglia of 6 common marmosets Callithrix jacchus following dopamine depletion by unilateral intracerebral 6-hydroxydopamine (6-OHDA) injections using three different survival times. The non-lesioned side served as an intra-individual control. Tyrosine hydroxylase immunoreactivity was strongly reduced in the entire ipsilateral striatum. Enkephalin-immunoreactivity was increased throughout the striatum. Substance P-immunoreactivity was significantly increased in only one case in the caudate nucleus and in two cases in the putamen, while in other cases either a non-significant increase or decrease was found. Therefore, the results of the present study indicate that in marmosets dopamine has a inhibiting effect on the levels of striatal enkephalin, while its effect on substance P (SP) appears to be absent.
Roeling
T A
TA
Department of Anatomy and Embryology, Vrije Universiteit, Faculty of Medicine, Graduate School Neurosciences, Amsterdam, The Netherlands.
Docter
G J
GJ
Voorn
P
P
Melchers
B P
BP
Wolters
E C
EC
Groenewegen
H J
HJ
D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects / Q000378:metabolism*; D001522:Behavior, Animal / Q000187:drug effects; D002144:Callithrix; D004298:Dopamine / Q000502:physiology*; D015259:Dopamine Agents / Q000633:toxicity; D004744:Enkephalin, Methionine / Q000378:metabolism; D004745:Enkephalins / Q000378:metabolism; D007150:Immunohistochemistry; D020267:MPTP Poisoning; D017072:Neostriatum / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D016627:Oxidopamine / Q000633:toxicity*; D013373:Substance P / Q000378:metabolism; D013565:Sympatholytics / Q000633:toxicity*; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D015259:Dopamine Agents; D004745:Enkephalins; D009479:Neuropeptides; D013565:Sympatholytics; D013373:Substance P; D004744:Enkephalin, Methionine; D016627:Oxidopamine; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine