7-Tesla evidence for columnar and rostral--caudal organization of the human periaqueductal grey response in the absence of threat: a working memory study

Fischbach, A. K.; Satpute, A. B.; Quigley, K. S.; Kragel, P. A.; Bianciardi, M.; Wald, L. L.; Wager, T. D.; Feldman Barrett, L.; Theriault, J. E.

doi:10.1101/2022.12.21.521479

bioRxiv · 10.1101/2022.12.21.521479

7-Tesla evidence for columnar and rostral--caudal organization of the human periaqueductal grey response in the absence of threat: a working memory study

Fischbach, A. K.·Satpute, A. B.·Quigley, K. S.·Kragel, P. A.·Bianciardi, M.·Wald, L. L.·Wager, T. D.·Feldman Barrett, L.·Theriault, J. E.

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Abstract

The periaqueductal gray (PAG) is a small midbrain structure that surrounds the cerebral aqueduct, regulates brain-body communication, and is often studied for its role in "fight-or-flight" and "freezing" responses to threat. We used ultra-high field 7-Tesla fMRI to resolve the PAG in humans and distinguish it from the cerebral aqueduct, examining its in vivo function in humans during a working memory task (N = 87). Relative to baseline fixation, both mild and moderate task-elicited cognitive demands elicited bilateral BOLD increases in ventrolateral PAG (vlPAG), a region previously observed to show increased activity during anticipated painful threat in both non-human and human animals. The present task posed only the most minimal (if any) "threat". The mild-demand condition involved a task easier than remembering a phone number, elicited a heart rate decrease relative to baseline, yet nonetheless elicited a bilateral vlPAG response. Across PAG voxels, BOLD signal intensity correlated with changes in physiological reactivity (relative to baseline) and showed some evidence of spatial organization along the rostral-caudal axis. These findings suggest that the PAG may have a broader role in coordinating brain--body communication during a minimally to moderately demanding task, even in the absence of threat.

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Fischbach, A. K., Satpute, A. B., Quigley, K. S., Kragel, P. A., Bianciardi, M., Wald, L. L., Wager, T. D., Feldman Barrett, L., Theriault, J. E.. 2022-12-22. 7-Tesla evidence for columnar and rostral--caudal organization of the human periaqueductal grey response in the absence of threat: a working memory study. https://doi.org/10.1101/2022.12.21.521479

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