Importance
Neurogenesis in the adult brain is still a relatively new discovery. It has been in the news recently because of all the research regarding it. There are many different studies that show that neurogenesis may play an important role in many processes.
Depression + Stress
It was initially believed that depression was caused by lack of serotonin levels in the brain. People experiencing depression have a reduction of volume in their hippocampus so it was suspected that there is link between depression and reduced hippocampal cell proliferation. Thus, increasing neurogenesis was seen as solution to depression. Recent studies have shown that antidepressants increase neurogenesis by activating the glucocorticoid receptor in the brain. Studies have also shown, however, that stress may also be a major contributor to the effects of antidepressants. As depression and stress are closely related, there has been research showing that antidepressants may actually be responding to the stress and not the lack of neurons in the hippocampus.
Diseases
Neurodegenerative diseases are those characterized by loss of function, structure and even death of neurons in the brain. Parkinson's, Huntington's and Alzheimer's are all examples of such diseases. It has been found that these diseases can alter any of the three steps of neurogenesis. There is also a study that shows that when neurons are lost due to these diseases, neurogenesis attempts to replace them. Due to this interdependence, studies indicate that biomarkers of neurogenesis can detect early symptoms of these diseases. Finding ways to increase neurogenesis in the brain can lead to discovery of new treatment methods.
Drug And Alcohol use
Chronic drug use leads to reduction in hippocampal function as well as production of new nerve cells in the dentate gyrus. Research has shown that by understanding how drugs reduce adult neurogenesis and finding ways to increase it can potentially solve the problem of drug addiction. Even moderate drinking can cause reduced neurogenesis.
Exercise
Research shows that moderate exercise can lead to an increase in neuroplasticity and neurogenesis. This idea could be beneficial to research regarding and protecting against aging, Alzheimer's, dementia, Parkinson's and strokes. Now exercise is not only good for your physical health, it benefits your mental health by increasing cognitive function, learning, and memory.
Memory
There are many studies that delve into the details of how exactly neurogenesis can affect the encoding and storage of memories in the brain. It was first believed that neurogenesis would improve your memory. However, there have been paradoxical findings where the increase in working memory tasks has decreased adult neurogenesis. There is still research being conducted on this topic.