Table 3.

Results of exploratory analysis showing all brain gray matter regions in which there was a correlation (positive or negative) between TSPO expression^/microglial activation (PK PET BPnd) and age in 43 healthy subjects at an uncorrected p < 0.05 threshold

Region	Spearman rho	p
Superior colliculi	–0.426	0.004
Cuneiform nuclei#	–0.331	0.030
Caudate+	–0.390	0.010
subthalamic nuclei*	0.334	0.029
hippocampi	0.322	0.035
Globus pallidus	0.360	0.018

^#Cuneiform nuclei, little studied in humans, are small nuclei adjacent and medial to inferior and superior colliculi. Cuneiform PET signal may reflect spillover from strong signal within colliculi. ^*Similar results were found in subthalamic subregions. Note that subthalamic nuclei are diencephalic regions included in the BrainstemNavigator atlas. ⁺One subject was found to have abnormally high signal in caudate as well as pallidum and putamen (>5 SD above mean.) Excluding this subject did not significantly change results in regions of interest or exploratory regions.