Brain & Behaviour

Sensory Stimuli Strategic Approaches in Treating Neurodegenerative Disorders

Introduction

Dopamine by far is considered as one of the most important neurotransmitter in the neurological cosmos. The Dopaminergic nerve cells have neural circuit connections all over the brain and spinal cord and thus these cells by their physiological behavior affect many neural routes all over the body. According to certain studies, Dopamine is not only associated with the proper locomotion and reward behavior but it also helps to trigger some of the very basic and positive emotional responses such as the serenity achieved by listening to music, the tasty pleasure of eating or the feeling of ecstasy during intercourse. Not only that but this typical neurotransmitter is also associated in development of some salient human psychological behaviors such as intelligence, vigilance, precision and agility. Any irregular or abnormal activity of dopaminergic nerve cells such as under production of Dopamine can have catastrophic effects on the whole body leading  not only to loss of  motor functions but also to anxiety, over responsivity, depression and neuro degeneration.

Background

Now a days, in many developing and third world countries such as Pakistan, the percentage of individuals with neurodegenerative disorders is increasing day by day. It is triggered by many reasons such as contaminated life style and environment which influence genetics. The current scenario indicates that a large portion of the population is prone to neurodegenerative disorders which not only compromises their physiological functions but also endanger the future generations.

One such disorder, in which the loss of motor functionality occurs is Parkinson’s disease. The onset of this disease is generally observed after the age of 40 (not mandatory for all the cases). The disease has both genetic and environmental precursors. The onset triggers slight rhythmic shakes very much similar to shivering in a single or different areas of body mostly appendages and digits that gradually increase their area making the spasm episodes more and more violent with the passage of time until the trembling condition becomes permanent resulting in the total loss of grip and movement in case of hands and legs. Biochemically, the reason behind this condition is the under production of Dopamine which gradually decreases with time leaving the person impaired. So the only way to reverse all this menace is to somehow trigger the proper production of Dopamine. Genetic engineering approaches along with molecular medicine do provide the solution to this enigma but both these techniques have their limitations, mainly the high cost and lack of approach of a common man to such techniques and products make them utterly useless. What if there were an alternative strategy that did not involve complicated procedures and high cost of production. It would be a perfect solution for a layman. Now due to advances in physiology and neuroscience, biologists have devised certain techniques that involve interfering with the physical stimuli and barriers of the body to ensure the order of desired physiological function.

Principle

The principle behind such strategies is simple. Just like a person suffering with myopia and hyper myopia can’t see properly. In order to attain the clarity in vision, he/she adjusts the lens and thresholds of his eyes by wearing glasses or contact lenses. Similarly, simply by exposing the body to certain specific stimuli, we can balance the normal production of dopamine by the body.

Experimental Design

Prof. Dr. Wolfgang Driever and his team at the University of Freiburg have been conducting experiments on the dopaminergic nerve cells of the brain and astoundingly they have discovered that certain groups of neurons in the forebrain actively produce dopamine when the subject is exposed to certain visual or tactile stimuli. The experimental trials were conducted on zebra fish larvae, the experimental version of which had optogenetic calcium sensors as markers to show the activity of dopaminergic neurons in the forebrain. These cells glow in the active state that can easily be observed under a microscope. On exposure to certain specific stimuli the zebra fish nerve cells showed normal dopamine activity.

The conclusive findings of the team were that intense sensory stimuli can motivate the fore brain to produce dopamine along with the fact that dopamine is somehow associated with the sensitivity of sensory organs of the body thus adjusting the responses and reactions to stimuli. This proves the fact that indeed dopamine is involved in development of intelligence and agility as we perceive everything with our sensory organs.

Until now, most of the research on dopamine associated complications has been done on the midbrain of vertebrates and humans. The importance of forebrain in such scenarios was never accounted. New experimental advances like this provides us with substantial evidence that certain alternative sensory stimuli strategies can provide a better solution to neurological complications.

Insights

  • The methodology mentioned above is one of the trending techniques in neurobiology. Researches have shown that mere production of dopamine by the body or its introduction in the subject reverses the devastating effects of neurodegenerative disorders such as Parkinson’s. The methodology simply involves physical therapies and sessions very much similar to those of a physiotherapist at a very low cost because no surgical or medicinal drugs are involved in the procedure.
  • The therapy can ensure modest to complete recovery from the impaired conditions like restless leg syndrome (A condition in which the patient experiences uncomfortable tingling and spasms in the leg during sleeping).
  • Such therapies can help to reduce the progression of Alzheimer’s disease as the production of dopamine is inversely proportional to the progression of Alzheimer’s.
  • Further researches on such dopaminergic neurons can provide validated information on how such diseases develop and in general how humans adapt to spontaneously and rapidly changing stimuli and conditions.

References

Sebastian Reinig, Wolfgang Driever, Aristides B. Arrenberg. The Descending Diencephalic Dopamine System Is Tuned to Sensory Stimuli. Current Biology, 2017; DOI: 10.1016/j.cub.2016.11.059

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About the author

Waleed Sohail Chohan

Waleed Sohail Chohan is currently finishing his BS from University of Gujrat. He is currently Biology Decoded's Director of Media Team and President of our Gujranwala Headquarters.