Scopolamine provocation-based pharmacological MRI model for testing procognitive agents

Area of Science:

• Neuroscience
• Pharmacology
• Medical Imaging

Background:

• Pathological cognitive impairment presents a significant unmet medical need.
• Current animal models for cognitive disorders lack predictive, face, and construct validity.
• Developing effective cognitive enhancers is hampered by inadequate models and differing outcome measures between species.

Purpose of the Study:

• To validate a novel rodent pharmacological magnetic resonance imaging (MRI) provocation model for testing cognitive enhancers.
• To assess the utility of this model in predicting the efficacy of procognitive agents.
• To enable direct comparison of cognitive agents across species using functional MRI.

Main Methods:

• Validation of a scopolamine-induced cognitive impairment model in rodents using functional MRI.
• Administration of known procognitive agents (donepezil, vinpocetine, piracetam, EVP-6124, PNU-120596) to assess their effects on blood-oxygen-level dependent (BOLD) responses.
• Correlation of functional MRI findings with performance in rodent cognitive tests (water labyrinth).

Main Results:

• The scopolamine-based rodent model demonstrated significant effects on BOLD responses for most tested procognitive agents, with piracetam being an exception.
• Functional MRI results were largely consistent with cognitive outcomes in the water labyrinth test, where only PNU-120596 showed no significant effect.
• The model proved suitable for evaluating the efficacy of compounds aimed at enhancing cognition.

Conclusions:

• The validated scopolamine-provoked rodent functional MRI model is a promising tool for preclinical assessment of cognitive enhancers.
• This model's ability to parallel human studies may improve the translation of findings and reduce failures in clinical trials.
• The approach facilitates the development of disease-modifying cognitive enhancers by providing a more predictive preclinical evaluation method.