Testing Different Combinations of Acoustic Pressure and Doses of Quinolinic Acid for Induction of Focal Neuron Loss in Mice Using Transcranial Low-Intensity Focused Ultrasound

The goal of this study was to test different combinations of acoustic pressure and doses of quinolinic acid (QA) for producing a focal neuronal lesion in the murine hippocampus without causing unwanted damage to adjacent brain structures. Sixty male CD-1 mice were divided into 12 groups that underwent magnetic resonance-guided focused ultrasound at high (0.67 MPa), medium (0.5 MPa) and low (0.33 MPa) acoustic peak negative pressures and received QA at high (0.012 mmol), medium (0.006 mmol) and low (0.003 mmol) dosages. Neuronal loss occurred only when magnetic resonance-guided focused ultrasound with adequate acoustic power (0.67 or 0.5 MPa) was combined with QA. The animals subjected to the highest acoustic power had larger lesions than those treated with medium acoustic power, but two mice had evidence of bleeding. When the intermediate acoustic power was used, medium and high dosages of QA produced lesions larger than those produced by the low dosage.