Concurrent assessment of neurometabolism and brain hemodynamics to characterize the functional brain response to psychotropic drugs: An S-ketamine study.

Summary

S-ketamine was tested in a study involving 32 healthy controls using a novel approach that combined pharmacological MRI and spectroscopy to assess brain responses. The results showed significant hemodynamic changes in specific brain regions, which correlated with increases in glutamate and lactate, particularly at higher doses. This method improved the prediction of whether participants received placebo or S-ketamine, demonstrating the effectiveness of using both imaging techniques together.

Study at a glance

Abstract

Neuroimaging techniques offer valuable insights for understanding pharmacological treatment effects in neuropsychiatric disorders. Here, we present a novel approach that simultaneously assesses hemodynamic and neurometabolic brain responses to psychotropic drugs using interleaved pharmacological magnetic resonance imaging (phMRI) and pharmacological magnetic resonance spectroscopy (phMRS). This method was tested using a double-dose, placebo-controlled, randomized, crossover design using S-ketamine as the pharmacological agent. We acquired 7 Tesla phMRI and phMRS data to evaluate time- and dose-dependent effects of S-ketamine in 32 healthy controls. S-ketamine elicited robust phMRI responses in the dorsofrontal, cingulate, and insular cortices, which correlated with glutamate and opioid receptor maps and subjective dissociation scores. These hemodynamic changes were paralleled by increases in glutamate and lactate, especially at higher doses. Furthermore, accuracy in predicting received condition (placebo, a low, or a high S-ketamine dose) increased when combining both techniques. Here, we show for the first time that concurrent phMRI and phMRS assessments provide important complementary insights into the functional brain response to pharmacological interventions.

Tags