Figure 2.

Experimental results from an [¹⁸F]fallypride bolus injection and hypercapnia challenges of 7% CO₂ applied five times for 12 min during the experiment (5×CO₂). (a) Time activity curves for putamen, thalamus and cerebellum are not noticeably affected by hypercapnia (timing of challenge indicated by shaded areas). (b) Measured cerebral blood flow changes with pcASL show increases in flow in the putamen and cerebellum ROIs during hypercapnia. (c) End-tidal CO₂ values are well-matched with flow changes for the duration of the experiment.