Mapping the structural connectivity between the periaqueductal gray and the cerebellum in humans

• Published in: Brain Structure and Function Vol. 224; no. 6; pp. 2153 - 2165
• Main Authors: Cacciola, Alberto, Bertino, Salvatore, Basile, Gianpaolo Antonio, Di Mauro, Debora, Calamuneri, Alessandro, Chillemi, Gaetana, Duca, Antonio, Bruschetta, Daniele, Flace, Paolo, Favaloro, Angelo, Calabrò, Rocco Salvatore, Anastasi, Giuseppe, Milardi, Demetrio
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2019; Springer Nature B.V
• Subjects: Adult; Automation; Biomedical and Life Sciences; Biomedicine; Cell Biology; Cerebellar Nuclei - physiology; Cerebellum; Cerebellum - physiology; Cerebral Cortex - physiology; Cognitive ability; Connectome - methods; Diffusion Magnetic Resonance Imaging - methods; Diffusion Tensor Imaging - methods; Female; Humans; Investigations; Magnetic resonance imaging; Male; Neural Pathways - physiology; Neurology; Neurosciences; Nuclei; Original; Original Article; Periaqueductal Gray - physiology; Periaqueductal gray area; Registration; Young Adult; Diffusion MRI; Connectome; CSD; White matter; Tractography
• ISSN: 1863-2653; 1863-2661; 1863-2661; 0340-2061
• DOI: 10.1007/s00429-019-01893-x

The periaqueductal gray is a mesencephalic structure involved in modulation of responses to stressful stimuli. Structural connections between the periaqueductal gray and the cerebellum have been described in animals and in a few diffusion tensor imaging studies. Nevertheless, these periaqueductal gray–cerebellum connectivity patterns have yet to be fully investigated in humans. The objective of this study was to qualitatively and quantitatively characterize such pathways using high-resolution, multi-shell data of 100 healthy subjects from the open-access Human Connectome Project repository combined with constrained spherical deconvolution probabilistic tractography. Our analysis revealed robust connectivity density profiles between the periaqueductal gray and cerebellar nuclei, especially with the fastigial nucleus, followed by the interposed and dentate nuclei. High-connectivity densities have been observed between vermal (Vermis IX, Vermis VIIIa, Vermis VIIIb, Vermis VI, Vermis X) and hemispheric cerebellar regions (Lobule IX). Our in vivo study provides for the first time insights on the organization of periaqueductal gray–cerebellar pathways thus opening new perspectives on cognitive, visceral and motor responses to threatening stimuli in humans.