Functional MRI Techniques Suggesting that the Stress System Interacts with Three Large Scale Core Brain Networks to Help Coordinate the Adaptive Response: A Systematic Review

Abstract

Objective: Synthesis of functional MRI (fMRI) and functional connectivity (FC) analysis data on human stress system (SS) function, as it relates to the dynamic function of the Salience (SN), Default Mode (DMN) and Central Executive (CEN) networks. Methods: Systematic search of Medline, Scopus, Clinical Trials.gov, and Google Scholar databases of studies published prior to September 2022 resulted in 28 full-text articles included for qualitative syn- thesis. Results: Acute stress changes the states of intra-/inter- neural network FCs and activities from those of resting, low arousal state in the SN, DMN and CEN, during which intra- and inter-network FCs and activities of all three networks are low. SS activation is positively linked to the activity of the SN and negatively to that of the DMN, while, in parallel, it is associated with an initial decrease and a subse- quent increase of the intra- network FC and activity of the CEN. The FC between the DMN and the CEN increases, while those between the SN and the CEN decrease, allowing time for frontal lobe strategy input and “proper” CEN activity and task decision. SN activation is linked to sensory hyper- sensitivity, “impaired” memory, and a switch from serial to parallel processing, while trait mindful- ness is associated with FC changes promoting CEN activity and producing a “task-ready state”. Conclusion: SS activation is tightly connected to that of the SN, with stress hormones likely potentiat- ing the intra-network FC of the latter, attenuating that of the DMN, and causing a biphasic suppres- sion-to-activation response of the CEN, all adaptive changes favoring proper decisions and survival.

Thematic Selection: Stress and Stress-related Disorders Neurobiology & Translational Aspects of Stress-related Disorders (Part 3)

“…The last two articles have focused on stress-related functional and structural imaging studies. Paltoglou et al offer an overview of functional MRI and functional connectivity analysis studies, which support the coordination of the stress response by three main dynamic networks [ 11 ]. On the other hand, Cardoner et al provide an overview of structural imaging studies investigating the impact of stress on brain morphology [ 12 ].…”