An atlas-based image registration method for dopamine receptor imaging with PET in rats

Area of Science:

• Neuroscience
• Radiology
• Pharmacology

Background:

• Positron emission tomography (PET) enables in vivo analysis of brain function.
• Accurate anatomical registration is crucial for quantitative PET studies in rodent models.
• Dopamine D2 receptors are key targets in neurological research.

Purpose of the Study:

• To develop a convenient and precise method for anatomical registration in rat brain PET imaging.
• To enable accurate quantification of dopamine D2 receptor binding in vivo.
• To compare dopamine D2 receptor binding across different rat strains.

Main Methods:

• Developed a stereotaxic positioning technique for aligning rat brains with a brain atlas during PET scans.
• Utilized [11C]raclopride for PET imaging of dopamine D2 receptors.
• Employed an atlas-based region of interest (ROI) approach for striatal and cerebellar identification.
• Calculated binding potential (BP) using a two-parameter compartment model with cerebellar input function.

Main Results:

• The developed method achieved precise anatomical registration for striatum and cerebellum.
• Binding potentials (BP) varied significantly across rat strains: Wistar (1.56+/-0.30), Sprague-Dawley (1.05+/-0.14), and Fischer F344 (1.29+/-0.07).
• Wistar rats exhibited significantly higher BP compared to Sprague-Dawley rats.

Conclusions:

• The novel PET imaging method provides objective and convenient anatomical registration for rat brain studies.
• This technique facilitates routine in vivo quantification of dopamine D2 receptor binding.
• The findings highlight strain-dependent differences in dopamine D2 receptor binding in rats.