Type 2 diabetes were compared with 30 controls volunteers

"Hippocampus" is a strange name, but we each have this brain structure which lies under the medial temporal lobe, one on each side of the brain.

Fifty-six people with Type 2 diabetes were compared with 30 controls volunteers, all non-diabetics. It was found the cortical sizes were smaller in the diabetic volunteers than in the control volunteers. Two regions of the brain, the hippocampal and the middle temporal gyrus, were especially small in the diabetics.

According to another study published in the Diabetes Metabolic Research Review, June 2011, the brain of women could be especially vulnerable to the effects of Type 2 diabetes and high blood sugar levels. Researchers at the New York University School of Medicine looked at the brain size and blood sugar levels in 40 obese Type 2 diabetes and 47 normal-weight healthy volunteers. Despite having better control of their blood sugar levels, women with Type 2 diabetes had proportionately smaller hippocampus sizes than did men.

What is the role of the hippocampus? The hippocampus is involved in:

* memory storage,
* sensations, and
* the regulation of emotions.

Most Americans can remember where we were and what we were doing when we heard the World Trade Center had been attacked on 9/11, but few of us remember the day before, or the day after. That is thought to be because 9/11 was an emotionally charged event.

We also often have clear memories associated with certain smells. One immigrant who had forgotten his trip as a child crossing the Atlantic in a ship, was able to recall the trip vividly years later when entering a boat and smelling similar odors. This is thought to be due to the hippocampal involvement in processing information from the sensory nerves leading from the nose. The hippocampus is also involved in spatial memory and navigation.

The middle temporal gyrus has been associated with recognizing faces, reading comprehension, and thinking about distance. It is also thought to be involved with speech and language.

The discovery of the connection between insulin resistance and memory storage and decision-making, will help many people who are losing their memory, whether or not they have Type 2 diabetes.