NRSC 4132 Blog

We Americans are so accustomed to a lifestyle of instant gratification, ease, and leisure; especially when making daily choices of what we consume individually. It's no surprise we face an unprecedented epidemic of obesity in this nation when you look at how corporate food companies cater to our demand for easy availability of virtually any type of food one could ever crave. Obviously location takes an important roll as well, but for most of us residing in urban areas, our communities are saturated with endless food options. We no longer need to get out of our car to get an eight-hundred calorie caramel macchiato in the mornings. There's something to be said about the fact that one can obtain endless high-fat and high-caloric meals at the very thought of hunger.

Researchers and statisticians seem to be very compelled in not only updating the nation's obesity statistics, but also in finding new ways to potentially counteract America's modern obesity outbreak. In the past, some of us have resorted to other behaviors and procedures in compensation such as workout rituals, personal trainers, diet pills, and even extreme actions like stomach-stapling, liposuction, etc. Regardless of whether they worked or not, it's about time something new came around.

In last month's publication of Nature & Neuroscience, and interesting study using mouse mutants to research insulin receptor function in the ventromedial nucleus of the hypothalamus (VMH). Provided that high-fat diets lead to the production of severely high levels of insulin (which we all know can initiate cascades of detrimental health issues such as diabetes, high blood pressure, etc.), Klöckener et al. suggest brain mechanisms in the VHM which if genetically modified, may be applicable to humans and anti-obesity treatments.

The VMH is a rather unclear and grey portion of the brain in terms of the knowledge that we currently know about it. We do know however, that it serves as one of the primary locations in the hypothalamus that mediates nutrient sensing, metabolism, and insulin receptor signaling. To guarantee an optimal energy environment for reproduction, the body monitors energy availability indirectly with the help of insulin and leptin that consistently circulate in the body. These two hormones can act to store fat as well as alert other metabolizing processes.

Steroidogenic factor 1 (SF-1) positive cells distribute across large parts of the VMH are directly involved with controlling systematic metabolism. These cells are highly responsive to insulin. Klöckener et al. identified a subpopulation of insulin-SF-1-positive cells in the VMH distinct from leptin-responsive neurons. They found that the systematic deletion of the insulin receptor in SF-1 expressing cells of the VMH caused no immediate changes in homeostasis. However, when both the control and mutant mice were exposed to high-fat diets, the modified SF-1 cell mice were protected from the development of obesity. It was reasoned that this protection from obesity was due to higher leptin sensitivity, since insulin was rendered useless in the mutant mice. Following this discovery, they found that the reinstatement of PtdInsP3 signaling downstream of the insulin receptor made the mutant mice that were previously protected from obesity, vulnerable again.

Even though all of the processes VMH carries out sill remains unclear, the mechanisms involved with insulin and high-fat diets are becoming clearer. These findings are on their way to future investigations where potential anti-obesity therapeutics may be revealed.

I think it's awesome that researchers are unveiling new methods that can potentially solve this epidemic in the near future and I strongly support such research for the benefit of the population. This compelling issue has not been mitigated to a satisfactory level even with counteracting behaviors as mentioned above. Statistically, just below twenty percent of the population in Colorado is diagnosed as clinically obese. It's ironic thought because Colorado tops the list for the least obese state in the nation. We clearly have to keep working, researching, and making changes in order for a valid solution to be found.