Exploring neurogenesis and harnessing its potentials.
“You don’t grow new brain cells” my mom would tell me time and time again. “Be sure to wear a mask when you play with spray paint…You can’t afford to have another concussion…don’t do drugs… Because you don’t grow new brain cells.” Mom was right. However, current frontiers in neuroscience now demonstrate that the old belief is not true. Well, kind of… it is not that simple. We do grow new brain and nerve cells. This phenomenon is called Neurogenesis. The important questions are how we grow new brain cells and to what degree.
Current frontiers in neuroscience now demonstrate that the old belief is not true. We do grow new brain and nerve cells. This phenomenon is called Neurogenesis.
What is Neurogenesis exactly?
Neurogenesis is the birth and growth of new neurons, brain cells in the adult human brain. Neurogenesis takes place on a daily basis and can even be stimulated. It is part of an innate natural process that reduces age’s degenerative effects on the brain.1 Current research is working to uncover specific methods that stimulate neurogenesis. However, before discussing them, let’s better understand the process of neurogenesis.
Neurogenesis occurs in certain regions of the brain because of specialized brain cells called astrocytes. Astrocytes have the ability to act as neural stem cells and in turn support lifelong neurogenesis.
There are two factors that determine the level of neurogenesis in an individual’s brain. The first one is called the local cell intrinsic potential. This refers to your unique genetic blueprint- how you are designed and therefore your own unique potential for function. The second one is the supportive microenvironment. This refers to the plethora of environmental factors that either support or limit your expression of health, or in this case neurological health. Some noteworthy environmental factors include nutritional status, quality of sleep, and regularity / type of exercise.
In some regions of the brain, dormant astrocytes can be provoked by an environmental condition to produce new brain cells. Exercise and intermittent fasting are two examples. On the other hand, in conditions of brain injury or stroke, the astrocytes are not stimulated to regrow damaged areas.2
Where neurogenesis occurs in the brain
Neurogenesis occurs in the different regions of the brain to varying degrees. One primary brain region in adult humans that can produce newborn brain cells is called the hippocampus. The hippocampus is responsible for learning, memory, mood and emotion. Jonas Frisén from the Karolinska Institute estimates that we produce up to 1,400 new neurons in the adult brain every day, with the rate declining as we age. By the time we turn 50, the original hippocampal neurons from birth are completely replaced by new ones.3
Importance of the hippocampus
The hippocampus is especially important for learning and memory, particularly spatial memory. When hippocampal function is blocked in a laboratory setting, those functions decline. This observation is interestingly reminiscent of the declined functions often seen in older age.
The hippocampus and depression
The hippocampus makes up part of the limbic system, responsible for emotion and memory. Neuroscientist Sandrine Thuret explains, there is a clear link demonstrated between neurogenesis and depression. Individuals with depression suffer from lower rates of neurogenesis and anti-depressant drugs have a positive impact on neurogenesis. Likewise, when neurogenesis is blocked in a clinical setting, it also blocks the effect of antidepressant drugs.3 Therefore depression is more than a mental-emotional state, it may also be considered as a marker for neurological vitality.
Seeing depression as a marker for neurological vitality, not just mental-emotional health.
Topics of neurogenesis – preserve and potentiate
The discussions surrounding neurogenesis split into two conceptual themes. The first one is to reduce cognitive decline, meaning, brain degeneration that is already occurring. The second focuses around optimizing an innate human potential to maximize our expression of vitality. Ultimately it boils down to working to reduce cognitive decline by preserving what you have and maximizing a functional potential.
Now, how can one begin to optimize the process of neurogenesis? One more element in this discussion requires introduction. That is Brain Derived Neurotrophic Factor or BDNF for short.
Neurogenesis and BDNF – Brain Derived Neurotrophic Factor
BDNF is the most abundant neurotrophin (growth factor) in the brain. BDNF, like a garden fertilizer, stimulates new neuronal growth. It serves as the key molecule involved in learning and memory. Furthermore, it serves as a regulator molecule and participates in neuroplasticity. (Neuroplasticity, is the term given to the brain’s ability to adapt and change and is the subject of the popular book The Brain That Changes Itself by Norman Doidge). Individuals with Alzheimer’s disease have significantly lower levels of BDNF.
Factors that stimulate BDNF production therefore stimulate neurogenesis.4 This in turn optimizes vital functions the body. Stimulating BDNF production and expression can be done through exercise, certain foods in the diet, Intermittent Fasting and more. In part 2 of this series, we will be exploring those positive strategies and specifics on how to implement them.
Disclaimer. The information represented in this article is meant to provide concepts from evidence based research. It is not intended to treat or diagnose any health condition. For appropriate treatment methods please contact your healthcare provider.
