Macro- and Microscale Stress-Associated Alterations in Brain Structure: Translational Link With Depression

Area of Science:

• Neuroscience
• Psychiatry
• Cell Biology

Background:

• Major depressive disorder (MDD) is a stress-related condition with poorly understood brain changes.
• Current detection methods for MDD-related brain alterations in living individuals are limited.
• Animal models and postmortem studies provide crucial insights into MDD pathophysiology.

Purpose of the Study:

• To review evidence linking corticolimbic alterations to MDD symptomatology using neuroimaging.
• To discuss cytoarchitectural changes in neurons, astroglia, and synapses in MDD and animal stress models.
• To highlight novel in vivo positron emission tomography (PET) approaches for measuring synaptic and astroglial alterations.

Main Methods:

• Review of magnetic resonance imaging (MRI) studies in humans and animals.
• Analysis of postmortem human brain tissue and rodent chronic stress models.
• Discussion of advanced in vivo PET imaging techniques.

Main Results:

• Corticolimbic alterations are associated with depression symptoms, observed via MRI.
• Similar cytoarchitectural changes in neurons, astroglia, and synapses are found in MDD and rodent stress models.
• In vivo PET enables measurement of synaptic and astroglial changes relevant to MDD.

Conclusions:

• Synaptic deficits and corticolimbic alterations are critical to MDD and chronic stress pathology.
• Animal models effectively replicate key MDD-related cytoarchitectural changes and behavioral deficits.
• Novel in vivo imaging techniques offer promising avenues for understanding MDD pathophysiology and guiding treatment.