Smells Like Science!

            There’s no question that the brain is the most complicated area of study in the human body. Just think that for decades it was thought that neurons cannot regenerate themselves which would mean the neurons you currently have are the same neurons you will have for the rest of your life. Continual studying of the brain has only recently led scientist to learn that there is such thing as neurogenesis in humans seen in the hippocampus (part of the brain for memory). But that’s not the only place new neurons are being discovered. Scientists from the NIH’s National Institute of Neurological Disorders and Stroke have discovered that there are constantly new neurons found in the mouse olfactory system (part of the brain that process smell). What’s more interesting is the critical effect these new neurons are having on the olfactory system and the brain overall!

            Scientists revealed that the newly found neurons found in the olfactory system are actually crucial for creating and maintaining neuronal connections from the olfactory bulb to the rest of the brain. This is interesting because it is typically understood that neuronal circuits in a healthy system are already stable, and the introduction of new neurons causes a disruption in the stability of the preexisting circuit. In this case however, “the circuitry appears to be inherently unstable requiring a constant supply of new neurons not only to recover its organization following disruption but also to maintain or stabilize its mature structure,” as said by Dr. Belluscio, lead author of this study. What this means is that this circuit in our brains that was originally thought to be stable is actually unstable, and that the new neurons coming into this circuit are what constantly organize and stabilize the neuronal circuit in the olfactory system.

            One might wonder why this discovery of the importance of newly found neurons in the olfactory system of mice is relevant to anything. Well before you blow this off as meaningless to our lives as humans, keep in mind that olfactory loss is actually an early indicator of neurodegenerative diseases like Alzheimer’s and Parkinson’s disease. This connection between diseases such as Alzheimer’s and Parkinson’s with the olfactory system is still a mystery to scientists today. Basically what I’m getting at is that as mentioned above, scientists have recently discovered that neurogenesis is occurring in the brain and newly formed neurons are being sent to the olfactory system to create and maintain organization of the neuronal circuits. Hopefully this recent discovery can help explain the currently unknown connection between loss of olfactory function and neurodegenerative diseases.

Source:

NIH/National Institute of Neurological Disorders and Stroke. "Scientists sniff out unexpected role for stem cells in the brain." ScienceDaily. ScienceDaily, 14 October 2014. <www.sciencedaily.com/releases/2014/10/141014095208.htm>.