What Is Neurogenesis?

When we are young, we think of our brains as pliable and able to retain new information as we learn. As adults, it can seem like we lose that plasticity. We find it more difficult to retain new information or recall information we once found readily available. 

We can gain an understanding of why we may feel like we’ve lost our edge by studying adult neurogenesis and learning how we can support this important brain function. We can also learn how to support the cells in our brain (and bodies) so that we thrive at every age. 

Two Types of Neurogenesis

The brain is made up of cells called neurons. Non-neuron cells have different differentiations but are collectively called glia. 

The process of making more neurons is called neurogenesis, and until recently, it was believed neurogenesis only occurred during embryonic development. Now, we know that neurogenesis can also occur in adulthood. 

Embryonic Neurogenesis

Developing new neurons during embryonic development is how our brains are created. The neural tube is formed as cells divide during the earliest stages of development. 

This is the very beginning of what will become the central nervous system. The brain reaches maturation around age 20. 

Continued development creates different areas of the brain. Neurons are diverse cell types, and this diversity is important to the development of different brain regions that are critical for all bodily functions. 

It was a long-held belief that we were born with all the brain cells we would ever have. If we lost brain cells due to injury or trauma, the brain wouldn’t make new neurons but would simply have less volume. 

Now, we know that the adult brain is capable of neuroplasticity, a way of creating new brain cells, reshaping itself and realigning neural pathways after injury, or resulting from neurodegenerative diseases. 

Adult Neurogenesis

Although the concept of adult neurogenesis was hypothesized in 1960, the only studies that showed neurogenic activity were in animals like fish and birds. Microglia, astrocytes, and oligodendrocytes are structural and immune cells inside the brain capable of cell division, but actual neural cells didn’t seem to have that same capability. 

Adult mammalian brain neurogenesis was considered impossible until scientists Joseph Altman and Gopal Das began trials in rats. 

Altman and Das intracranially injected thymidine, a marker for cell proliferation, and examined the results. They found that the thymidine marked cells that had characteristics of new neurons located in the olfactory bulb and the dentate gyrus. These two brain zones control processes like smell and memory. 

They also found that these cells within the mouse brain also had dendrites and synapses, which meant they were functioning as neural cells, not simply glial cells. 

Because neurogenesis was now discoverable in the brain of an adult mouse (a mammal with similar brain structure and function to humans), it was also hypothesized that it was possible in the adult human brain. 

The scientific community accepted this in the early 1990s after a study published by Richards, Kilpatrick, and Bartlett discovered the presence of stem cells (also known as precursor cells) in adult rat brains. 

Where Neurogenesis Happens

New cells aren’t made throughout all parts of the adult brain. In fact, neurogenesis only happens in two areas: the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone (SGZ) of the dentate gyrus within the adult hippocampus (the hippocampus being a small structure located in the cerebral cortex). 

These two areas appear to be specialized specifically for making new cells. 

Because there is a direct relationship between the hippocampus and depression, researchers focus on the SGZ to understand how antidepressant medications work. Over half of the neural stem cells located in the SGZ can relocate to other areas of the brain and establish connections with other neural cells, allowing synaptic function to continue properly. 

How Does Neurogenesis Impact Cognitive Function?

Because of these pioneering discoveries, we now have a better way of approaching cognitive dysfunction and degenerative diseases like Alzheimer’s disease. 

By examining the signaling pathways by which neurogenesis occurs, we can find better strategies for treating cognition problems and disease. 

Studies of the cells proliferated in the SGZ have found that specific cells, called dentate granule cells, are created here. These cells are important for learning and the retention of learned information. The cells proliferated in the SVZ usually become interneurons, which help other neurons communicate with one another. 

How Many New Cells Will We Make?

During our lifespans, it’s estimated that at least one-third of the neurons located in the hippocampus will be replaced with new neural cells. These new cells help mainly with regulatory functions like mood, memory, and learning. 

New cellproliferation is also important for synaptic plasticity, or how the brain can change specific communication pathways and circuitry in the presence of illness or trauma. This plasticity is also important in continuing to change and learn as we age. 

Supporting Neurogenesis

Neurogenesis naturally declines as we age. Because neurogenesis plays a key role in helping protect us from memory loss and cognitive decline, supporting the ability to continue making new cells is essential. 

Lifestyle factors like maintaining healthy blood glucose levels, regular exercise, and getting enough sleep are key to supporting our brain health. Now, we know of another way to support our brain cells (and every other cell in our body, too).

Fatty15: Cellular Support Made Easy

A newly discovered essential fatty acid called C15:0 has been found to offer numerous benefits for your cells:*

• Cell membrane support, so your cells remain protected and strong.
• Improved mitochondrial function, so cells can operate at max capacity.
• Better cellular signaling, so cells can communicate with each other.

C15:0 isn’t readily available in our diets because it’s found mostly in whole-fat dairy, and as a society we have been decreasing our intake of full-fat milk, instead drinking milk replacements like oat, almond and soy milk, which contain no C15:0. However simply increasing our intake of whole-fat dairy would mean more calories and more exposure to unhealthy, pro-inflammatory, even-chain, saturated fats. A solution? Fatty15.

Fatty15 is the first and only C15:0 supplement.. Fatty15 contains pure C15:0 and is a vegan friendly, sustainably produced and award winning supplement. Just one capsule per day is enough to support your cells, improve your focus, and restore balance to your body.* 

Ready to learn more about this cell-supporting fatty acid? Explore the science behind fatty15 and C15:0 here. 

Sources:

What is Neurogenesis? | Simply Psychology

Adult Hippocampal Neurogenesis in Different Taxonomic Groups: Possible Functional Similarities and Striking Controversies | PMC

Hippocampal Neurogenesis | PMC

De novo generation of neuronal cells from the adult mouse brain | PubMed

Efficacy of dietary odd-chain saturated fatty acid pentadecanoic acid parallels broad associated health benefits in humans: could it be essential? | Scientific Reports