Researchers discover the source of new neurons in brain's hippocampus

on 31 March 2019
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Subgranular layer of the dentate gyrus

Deep within your brain, some little critters called neuronal stem cells, are hard at work helping you build memories and, hopefully, a very happy and enjoyable life. The secret to that life though is while they are hard at work; you shouldn't be. . . . 

This appears to be the neuronal version of "an apple a day, keeps the Doctor away!" What I mean by that, is, that the fact that neural stem cells grow in the dentate gyrus of the hippocampus is a well-established fact, so what they seem to be saying here is that these stem cells come from the same embryonic population and replicate themselves throughout our lifetime, from embryo to death, so to speak! Although the centre for smell, the olfactory (system) bulb is a new one on me, so some more research to do? The other major brain region where we produce neural stem cells is in the subventricular zone.

There are actually two main centres in the brain that produce neural stem cells, 1) the subgranular zone, this is a layer between the hilus and granule cell layer of the dentate gyrus of the hippocampus (as illustrated in the image above) and 2) the subventricular zone - SVZ - (part of the ventricular system of the forebrain). During the embryonic phase, all of our brain's neurons and glia develop from the ventricular zone and eventually migrate to the SVZ sometime after birth for the rest of our life. 

The most important factor, relating to the work that I do as a clinical hypnotherapist, is in the first area, the hippocampus and this is because of the ways in which stress and anxiety disorders disrupt neural stem cell production in the dentate gyrus of the hippocampus. This is important because these new stem cells play a crucial role in the formation of new memories and if we are too stressed, for too long, the hippocampus actually shrinks (hippocampal atrophy). So, obviously, the answer is to become more calm and relaxed and nothing can help you become that more than hypnosis and hypnotherapy.

The hypnotherapist uses their training, skills and experience to help you discover the source of the issue and then, via hypnosis, a psychotherapeutic intervention is delivered, effectively straight into the deeper levels of the brains language, the subconscious mind. From there, via sleep states and the proliferation of ponto-geniculo-occipital (PGO) waves during the hypnotic experience and subsequently through neural stem cells migration new memories are created. Through a process called long term potentiation, these new memories become habitual behaviours and this explains the permanence of hypnotherapy. For the most part, all behaviour is memory dependent, if you don't have a memory of something then it cannot be repeated, with, perhaps, the exception of reflexes! So, in order to create new behaviours and habits that you want to develop, you need to keep your daily build-up of neuronal stem cells flowing and the best way to do that is by being calm and relaxed as often as is possible. Hypnosis, post-therapy, will help you to maintain this peaceful and harmonious state!

Over the years I have had many clients presenting with anxiety and stress disorders, some respond very quickly and others take longer. Having said that, each client experiences hypnosis differently, so one would think that the ones who respond quickly, as in, more susceptible to hypnosis, would be the ones who get quicker relief to their anxiety and the ones who have to work a little harder (as in a few more sessions or methods of delivery) at hypnosis are the ones that take longer . . . but that isn't always the case. So, there has to be something directly related to the way their brain responds to sensory stimuli that makes this anomaly between the condition and hypnotic response factor? Some of that could be genetic, as it is known that the children of mothers who experienced a lot of anxiety/stress during their pregnancy are more likely to be predisposed to anxiety related issues. However, mostly our brain develops because of environmental factors, i.e. our experiences, living environment etc. and as children, we develop strategies of how to cope but these are childlike strategies and while they may work for us as children, they may not be at all useful to us as adults. However, the degree to which these strategies relate to emotionally, perceived, survival matters, to a child, is the degree to which they have the potential to maladapt as we develop from a child to adolescent, to adult; hence why some very mature and responsible adults behave like children when anxious or stressed! Other factors can be the possibility of brain lesions, as a consequence of a previous head injury or maybe an infection/disease or being exposed to trauma, be it via man-made or natural events (terrorist attacks, earthquakes) or even cumulative trauma, being told you are stupid, useless, no good etc. over and over.

So, the causes of anxiety disorders are varied and many and because of that of the way in which our brain is willing to respond to any particular type of therapeutic treatment, is somewhat dependent on the initial causes and developmental processes within and across the many areas of the brain that are involved in maintaining normal living as opposed to defensive living. Therefore, the more we can discover about the possible nature and development of an individual client's anxiety, the greater the prospect there is, for a complete and lasting recovery and most likely without the need for any medication!

If you are suffering from unwanted and unnecessary anxiety or stress, now is the time to seek help, hypnotherapy can provide you with that!

Hypnotherapy stands out as one of the most effective strategic life management methods there is, especially in its ability to promote clear thinking and good states of mental wellness. The behaviours that make life challenging are often a result of too much stress, too little sleep and too little by way of clarity! So, to get or take back control of your mind and your life, it makes perfect sense to use a methodology that addresses the subconscious mind's role in perpetuating negative, vague and ambiguous states of mind. Hypnosis helps us to create calm relaxing states of mind that make life work better! If you would like to address any concerns you have in this direction, or, if you just want to make your life feel better,  then why not make an appointment for a Free Consultation? Hypnosis gives you the ability to have a good life! 

The objective here is to help people understand how and why we become illogically trapped into irrational emotional experiences that may actually be happening for reasons different to that which we would imagine! If you want to know more about how Hypnotherapy can help you; why not make an appointment for a Free Consultation?

For more information on the Free Consultation - Go Here or to book your Free Consultation today, you can do so here

The Research:

It was once believed that mammals were born with the entire supply of neurons they would have for a lifetime. However, over the past few decades, neuroscientists have found that at least two brain regions -- the centres of the sense of smell and the hippocampus, the seat of learning and memory -- grow new neurons throughout life.

Researchers from the Perelman School of Medicine at the University of Pennsylvania have shown, in mice, that one type of stem cell that makes adult neurons is the source of this lifetime stock of new cells in the hippocampus. Published this week in Cell, these findings may help neuroscientists figure out how to maintain youthful conditions for learning and memory, and repair and regenerate parts of the brain after injury and ageing.

"We've shown for the first time, in mammals, that neurons in the dentate gyrus of the hippocampus grow and develop from a single population of stem cells, over an entire lifespan," said senior author Hongjun Song, PhD a professor of Neuroscience. "The new immature neurons are more flexible in making connections in the hippocampus compared to mature neurons, which is paramount for healthy learning, memory, and adjusting mood."

The researchers showed that the neural stem cells they found had a common molecular signature across the lifespan of the mice. They did this by labelling neural stem cells in embryos when the brain was still developing and following the cells from birth into adulthood. This approach revealed that new neural stem cells with their precursor's label were continuously making neurons throughout an animal's lifetime.

"This process is unique in the brain," said co-senior author Guo-li Ming, MD, PhD, a professor of Neuroscience. "In the hippocampus, these cells never stop replicating and contribute to the flexibility of the brain in mammals."

This capacity is called plasticity, which is the brain's ability to form new connections throughout life to compensate for injury and disease and to adjust in response to new input from the environment. Ming likens the process of new neuron growth in the hippocampus to adding new units into the circuitry of the brain's motherboard.

The teams' next steps will be to look for the same neural stem cells in other mammals, most importantly in humans, starting the search in post-mortem brain tissue, and to investigate how this population of neural stem cells are regulated.

This work was funded by the National Institutes of Health (P01NS097206, R37NS047344, R35NS097370, R01MH105128), EMBO, and the Swedish Research Council.

Story Source:

Materials provided by the University of Pennsylvania School of MedicineNote: Content may be edited for style and length.

Journal Reference:

  1. Daniel A. Berg, Yijing Su, Dennisse Jimenez-Cyrus, Aneek Patel, Nancy Huang, David Morizet, Stephanie Lee, Reeti Shah, Francisca Rojas Ringeling, Rajan Jain, Jonathan A. Epstein, Qing-Feng Wu, Stefan Canzar, Guo-Li Ming, Hongjun Song, Allison M. Bond. A Common Embryonic Origin of Stem Cells Drives Developmental and Adult NeurogenesisCell, 2019; DOI: 10.1016/j.cell.2019.02.010

Cite This Page:

University of Pennsylvania School of Medicine. "Researchers discover the source of new neurons in brain's hippocampus: Findings extend understanding of how a continuous supply of neurons throughout life is connected with learning and memory." ScienceDaily. ScienceDaily, 28 March 2019. <>.