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Updated: Jul 11, 2026
Functional Neuroimaging Using Ultrasonic Blood-brain Barrier Disruption and Manganese-enhanced MRI
Published on: July 12, 2012
Manganese-enhanced MRI in a rat model of Parkinson's disease
Galit Pelled1, Hagai Bergman, Tamir Ben-Hur
1MRI/MRS Laboratory, Human Biology Research Center, Department of Medical Biophysics and Nuclear Medicine, Hadassah Hebrew University Medical Center, Jerusalem, Israel.
Purpose:
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.
Material And 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.
Conclusion:
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.
Insights
Parkinson's disease (PD) in rats shows altered brain connectivity. Manganese-enhanced MRI reveals changes in basal ganglia (BG) networks, supporting the interhemispheric connectivity hypothesis in PD.
Area of Science:
- Neuroscience
- Neuroimaging
- Parkinson's Disease Research
Background:
- The basal ganglia (BG) play a crucial role in motor control.
- Altered connectivity within and between BG nuclei is implicated in Parkinson's disease (PD).
- The interhemispheric connectivity hypothesis proposes significant changes in BG network communication in PD.
Purpose of the Study:
- To investigate intra- and inter-hemispheric BG connectivity in a unilateral 6-hydroxydopamine (6-OHDA) rat model of PD.
- To test the validity of the BG interhemispheric connectivity hypothesis in this PD model.
Main Methods:
- Utilized manganese-enhanced MRI (MEMRI) for assessing neural pathway activity.
- Administered manganese chloride via direct injection into key BG nuclei: entopeduncular (EP), substantia nigra (SN), and habenula.
- Compared MEMRI signal enhancements in 6-OHDA lesioned rats (N=22) versus sham-operated controls (N=16) at multiple time points post-injection.
Main Results:
- EP nucleus manganese injection showed bilateral habenular enhancement, more pronounced in 6-OHDA rats, and reduced sensorimotor cortex signal.
- SN manganese injection led to increased thalamic and habenular signals in 6-OHDA rats.
- Habenula manganese injection revealed heightened interpeduncular and raphe nuclei signals in 6-OHDA rats.
Conclusions:
- Observed modulations in intra- and interhemispheric BG connectivity in the 6-OHDA PD rat model support the interhemispheric connectivity hypothesis.
- Findings suggest a potential link between dopaminergic and serotonergic systems in PD pathophysiology, correlating with clinical symptoms.
