Bipolar: What is Going on in the Brain?

Bipolar and the Brain

So what’s going on in the brain of people with Bipolar Disorder? There are multiple theories about Bipolar and the Brain. We are blessed with different types of imaging such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), near infrared spectroscopy (NIRS), and a ton more.  Because of these ways to image the brain, we can see that the neurons have different circuits where neurotransmitters are passed from one part of the brain to the next.  When there is disturbance in these circuits things go wrong in the brain. It’s similar to your lamp. If there is something wrong in the cord, or the light bulb is burnt out, you can’t effectively use the lamp.  It’s the same with the brain.

In Bipolar, studies using different types of imaging have shown that there is abnormalities in the fronto-limbic-subcortical circuits. This is not just one loop by one set of neurons as it might look like in the following picture but rather there are many many of these circuits. The areas affected are associated with the ability to regulate emotions.

The hippocampus is another are in the brain that neuroscientists suspect there is a problem. The hippocampus is in the lower part of the temporal lobe. You might remember the hippocampus plays a role in memory, attention, and emotion. The hippocampus helps you to remember the past and look forward to the future.  When people are depressed, the hippocampus shrinks. Remember that in bipolar depression, those who suffer often just want to die because of the severity of the depression. We could hypothesize that the hippocampus in that person will not allow them to look forward to the future. When you have no hope of a future, you want to die.

Another area of the brain in question, include various areas of the white matter of the brain. The gray matter is on the outside of the brain while the white matter is on the inside. Remember that white matter is made up of billions of neurons.  Hyperintensities in the white matter may be responsible for some of the problems found in Bipolar Disorder. Hyperintensities are what would show up in imaging.  These hyperintensities are found on the same circuits we talked about above, the fronto-limbic-subcortical tracts. They find in cadavers and during imaging, there are fewer of a specific type of neuro called oligodendrocytes in the front of the brain.

Why is Bipolar Disorder important to understand? Because it’s one of the leading WORLD WIDE causes of disability and death. We can help prevent Bipolar Disorder in a number of ways.  Although there is a genetic component to Bipolar Disorder, there are also many environmental issues that when attended to, can assist in preventing Bipolar Disorder. A wide label I could use would be trauma.  I will be addressing the idea of trauma in another post, but let me mention some of the traumatic experiences that people who have Bipolar Disorder may have gone through.

• Drugs or infection in the womb
• Maternal smoking
• Economic instability
• Child abuse- physical, sexual, emotional
• Neglect
• Lack of social support

These are only a few of the possibilities. I think it is important that we don’t say, “This has nothing to do with me,” because it does. We need everyone to help stop these things. We need each other. Anyway, I will talk about how we can help, in a future post.

Thanks for reading about Bipolar Disorder. If there are things you want to me to cover, please write in the comment area and I would love to address them.

References:

Frey, Benicio N.a e; Andreazza, Ana C.a b; Nery, Fabiano G.c f g; Martins, Marcio R.d; Quevedo, Joãod; Soares, Jair C.h; Kapczinski, Flávioa The role of hippocampus in the pathophysiology of bipolar disorder, Behavioural Pharmacology: September 2007 – Volume 18 – Issue 5-6 – p 419-430.

Mahon K, Burdick KE, Szeszko PR. A role for white matter abnormalities in the pathophysiology of bipolar disorder. Neurosci Biobehav Rev. 2010 Mar;34(4):533-54. doi: 10.1016/j.neubiorev.2009.10.012. Epub 2009 Nov 6. PMID: 19896972; PMCID: PMC2847441.