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Brain structure

Brain structural alterations have been observed in people with bipolar disorder. These alterations are have been found using magnetic resonance imaging (MRI), diffusion tensor imaging (DTI) and optical coherence tomography (OCT). Cellular changes have also been investigated. Click on the links or the tabs below to access the information, or browse the drop-down menu to the left.

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Cellular changes

What are brain cell changes in bipolar disorder? Neurons send and receive information via electrical and chemical processes in the brain. Interneurons are a subset of neurons that are involved in the processing and modulation of information. Glial cells are brain cells that play a role in neurodevelopment, neurotransmission, connectivity, brain metabolism, and the clearance of extracellular ions and neurotransmitters. Astrocytes are the most prevalent glial cell and are primarily involved in neurodevelopment. They also regulate synaptic transmission, mediate glutamate reuptake, and aid in the maintenance of the blood-brain barrier. Oligodendrocytes are glial cells that produce myelin that is used…

Diffusion tensor imaging

What is diffusion tensor imaging (DTI)? DTI is a specialised imaging technique that uses MRI technology to investigate the movement of water within tissues of interest. It is a powerful imaging method for characterising the integrity of white matter circuitry because it links anatomical and functional neuroimaging. By applying a magnetic field, the movement (“diffusivity”) of water molecules can be visualised in vivo. The diffusion of water is influenced by the cellular structure of the surrounding tissues, and measures such as fractional anisotropy were derived as an approximate measurement for the freedom of movement. In areas of high structural coherence…
MRI

Magnetic resonance imaging

What is magnetic resonance imaging (MRI)? MRI is based on the magnetisation properties of cellular protons. The application of a strong magnetic field causes the protons within cells to shift direction, which will return to their original position over time (“precession”). The rate of precession differs across tissue types (such as grey matter and white matter in the brain), which can be interpreted by specialised programs to represent a 3D image. What is the evidence for MRI findings in people with bipolar disorder? Grey matter decreases compared to controls High quality evidence shows small decreases in hippocampal subfields in people…

Optical coherence tomography

What are optical coherence tomography changes in bipolar disorder? Optical coherence tomography (OCT) is an imaging technology that assesses the thickness of the peripapillary retinal nerve fibre layer, macular thickness, and volume. It has been used to assess neurologic diseases such as multiple sclerosis, Alzheimer’s disease, and Parkinson’s disease, and more recently, in bipolar disorder. What is the evidence for OCT in people with bipolar disorder? Moderate to low quality evidence finds a large reduction in overall peripapillary retinal nerve fibre layer thickness in people with bipolar disorder, particularly in the inferior retinal nerve fibre layers. December 2021 Image: ©Med…

NeuRA Libraries

Title Colour Legend:
Green - Topic summary is available.
Orange - Topic summary is being compiled.
Red - Topic summary has no current systematic review available.