Manganese-enhanced MRI in a rat model of Parkinson's disease.
OBJECTIVE
To measure intra- and inter-hemispheric connectivity within the basal ganglia (BG) nuclei in healthy and in unilateral 6-hydroxydopamine (6-OHDA) Parkinson disease rat model in order to test the BG interhemispheric connectivity hypothesis.


METHODS
The manganese-enhanced MRI (MEMRI) method with direct injection of manganese chloride into the entopeduncular (EP), substantia nigra (SN), and the Habenula nuclei in unilateral 6-OHDA (N = 22) and sham-operated (N = 16) rat groups was used. MEMRI measurements were applied before, 3, 24, and 48 hours post-manganese injection. Signal enhancements in T1-weighted images were compared between groups.


RESULTS
Manganese injection into the EP nucleus resulted with bihemispheric signal enhancements in the habenular complex (Hab) at both groups with stronger enhancements in the 6-OHDA group. It also exhibited lower sensorimotor cortex signal enhancement in the 6-OHDA rat group. SN manganese injection caused enhanced anteroventral thalamic and habenular nuclei signals in the 6-OHDA rat group. Manganese habenula injection revealed enhanced interpeduncular (IP) and raphe nuclei signals of the 6-OHDA rat group.


CONCLUSIONS
Modulations in the effective intra- and interhemispheric BG connectivity in unilateral 6-OHDA Parkinson's disease (PD) rat model support the BG interhemispheric connectivity hypothesis and suggest a linkage between the dopaminergic and serotonergic systems in PD, in line with clinical symptoms.
Pelled
Galit
G
MRI/MRS Laboratory, Human Biology Research Center, Department of Medical Biophysics and Nuclear Medicine, Hadassah Hebrew University Medical Center, Jerusalem, Israel.
Bergman
Hagai
H
Ben-Hur
Tamir
T
Goelman
Gadi
G
D000818:Animals; D001479:Basal Ganglia / Q000473:pathology; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D002467:Cell Nucleus / Q000378:metabolism; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008345:Manganese / Q000494:pharmacology*; D016627:Oxidopamine / Q000494:pharmacology; D010300:Parkinson Disease / Q000175:diagnosis* / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism; D013997:Time Factors
D012701:Serotonin; D008345:Manganese; D016627:Oxidopamine; D004298:Dopamine