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Neuroscience Interview

This was my original interview with a Neurobiologist expert in the motor system. Email me for full disclosure of the Professor


Lately appropriate fitness program has been focusing in the  motor system, motor learning and motor planning instead of  training one isolated muscle (like bodybuilding)

Why is so important the motor system for the human being?

JM: The motor systems of the brain and spinal cord control every movement we make, from the simplest to the most complex. Movements define us as humans every bit as much as our intellect, or our art. Movements have allowed us to excel over animals throughout evolution. Movement gives us mobility; to choose to go where and do what we want. Just as movements become hampered—such as weakness or paralysis after stroke or slowed by Parkinson’s disease—we loose something is important to us.

Are motor skills really important as well?

JM: Yes. It is our skills that got us where were are today! Certainly not our brut strength. Like a sharp intellect confers great advantage, so too do well honed skills. In many professions, like athletes, dancers, or surgeons, the need for motor skill is obvious. Most of the time it is not so obvious, but nonetheless important. Think about it, when you are trying to fix a loose screw in a pair of eyeglasses or tying a bow, driving a car, peeling potatoes.

I also think that we take a certain measure of skill for granted that allows us to focus on other aspects of our live, which may not require as much motor skill. When each movement becomes a burden, it robs us of a broader spirit.


You mention that the Cerebellum is a “motor control structure”  what does it mean?

JM: It helps to control our movements. Let me give you an example. Our cardiovascular system includes our heart and all of our arteries and veins. Damage to the heart, a pump, affects the system on a whole. It doesn’t work well, even if our arteries are working just fine. The motor system has many components, located in many different parts of the brain and spinal cord. One component is the cerebellum. It is important in coordination, among other things.


The Cerebellum has three different parts. Why are these parts so important?

Each part contributes something different to the overall function of the cerebellum and the motor system. One for posture and balance, one for coordinating movements of our arms and legs, and a third for helping us to plan our movements.

How different are Purkinje cells in the Cerebellum  from the “traditional” neurons in the rest of the brain?

I think they are different in several ways. Let me tell you about two. First, they take in an enormous amount of information. Think of a big tree with lots of branches and leaves. This is like a Purkinje cell; the branches and leaves are receiving information from other parts of the nervous system. They have more “branches and leaves” than other nerve cells. Second, they are different in another way; they inhibit the firing of other neurons.  Most neurons that receive so much information excite other neurons; Purkinje cells inhibit. We don’t know why this is the case.


The Cerebellum receives information form the sensory systems—the somatic sensory system as well as the other major senses—sensory system, somatic sensory system, and cortical control centers. How is that related to muscle movement?

How important is sensory information when it comes to movement.

Movements are adapted to the goals at hand; movements are purposeful. To make movements effective, they are fine-tuned to the environment. For this to happen we need the help of the sensory systems. When we reach for a water bottle, we need to see where it is, precisely. When we step, we need to make sure where the ground is. This occurs because the sensory systems communicate with the motor systems. The cerebellum receives a lot of sensory information, but its job is not just a passive receiver. It needs to figure out what aspects of sensation are important for controlling movements.


Why is proprioception important for brain activity? In general terms How does our brain process information from our proprioceptors?

Proprioception provides critical information about the position of our body; not just our posture but the position of our limbs. It is like having GPS in our fingers, toes, hip, knees, etc.

It is not something we normally think about. It is not like listening to sounds. Because it is so basic, even subconscious, we don’t have to think about it from moment to moment. The information is present for our motor and sensory systems to use, all the time. It is important because it is the only way to tell the brain our position.

Proprioception is processed in two different ways. One way is best for movement control. That information makes its way quickly to different parts of the motor systems, primarily to the motor parts of the cerebral cortex and to the cerebellum. The other way for processing proprioceptive information is sending to sensory areas of the brain, like the somatic sensory areas of the cortex. We think that the motor areas process the information in “real time,” as it is needed to control movement. The sensory areas may be important in generating a body image, our notion of our size and where our limbs our; our body space.


In theory Do you think that 10 minutes of specific brain exercises a day is a good start? Would synapses strengthen if we are consistent?

Time is a hard question to answer. Consistent neural processing of new information over 10 minutes is certainly enough to produce lasting changes in the properties of nerve cells. But this is mostly studied in animals, and in very specialized kinds of experiments. It is hard to extend this, in a quantitative way, to people performing movement tasks. Also, each person is different. Starting from scratch, in a person who has not exercised much, a short time is apt to be more effective than the same short time in someone who has a lot of exercise experience. This is as much as I can say.

Yes, synapses strengthen when we are consistent. {{The also can strengthen when we are not, if the circumstances are particularly stressful or life threatening.}}


neurotrophic factors are produced in animals during exercise. this might lead to new connections. Is BDNF important for our brain?

Definitely. It is both important for maintaining connections and is important for making new connections, and maintaining these new connections. But there are many other neurotrophic factors (NT). We are just beginning to learn about how BDNF and other NTs are important.


Latest research has shown that cerebellum has non only motor but non motor capabilities such as cognitive learning,problem solving and speech. How is that possible?

The cerebellum receives information from all over the brain, processes this information, and sends it back to many specific parts of the brain. It is performing a specific function on that in-coming information, like a computer. For the past century or more, we have focused on its motor functions, especially since when the cerebellum is damaged most people lose the capacity to make coordinated movements. For movements, the cerebellum is fine tuning the timing and strength of muscle contractions to make the movements more effective. It does this by sending specifically timed neural signals to other brain regions and making sure that the signals are of the correct strength. We think it is doing a similar kind of function for speech and cognition. Not making adjustments for muscle contractions, but rather adjusting the timing and strength of neural signals for problem solving, etc.

What is a cognitive reserve? How we can create them?

Cognitive reserve refers to how resistant a person is to damage of the parts of the brain that are important for cognition. Damage to cognitive centers of the brain will obviously impair cognition. For a given amount of damage, we might expect a certain level of impairment. If the neural circuits for cognition are stronger in one person than another, there is evidence that the person with the stronger circuits can suffer more physical damage before showing a cognitive impairment.

Generally it is thought that we build a cognitive reserve by engaging in a lifestyle that is continuously challenging. We think that this strengthens neural circuits.


Can learning new motor coordination patterns stimulate the cerebellum and create new synapses in theory?

In theory, yes. The cerebellum is clearly important in learning new coordination patterns. But it is more than just the cerebellum. Many other parts of the motor systems respond to this challenge, especially the cerebral cortex motor centers and the areas of the nervous system that these cortical centers connect, such as the spinal cord.

Why is important for human beings to learn new coordination patterns?

I think it is just like continuously challenging the cognitive systems. It maintains the circuits for coordination/complex movements and builds new connections.

Why it could be specially important for Alzheimer disease?

Movements, and complex ones with novel coordination patterns in particular, recruit the entire brain. Not just the motor systems, but cognitive and memory systems as well. Maybe even the emotional systems, when we are pleasure or pain from our actions! For complex movements, we have to plan on the fly. It is very challenging. We need to tune into the proprioceptive capabilities of our sensory systems.


According to Lice the sensory system is one of the first systems to experience a deterioration with aging specially in specific conditions such as Alzheimer. Why do think this happens? Could we prevent this in some way?

I don’t know. My hunch is that sensory systems depend on sensory receptors in the skin, muscles, ear, eye, etc. We know that many of these sensor change with age; become less sensitive. This may be compounded by a deterioration of neural circuits in the brain that process this information.

I don’t know if we can prevent this. For the peripheral changes, probably not. For the central nervous system change, there is hope. Having an active lifestyle helps. Consider vestibular dysfunction and balance impairments, for example. Our sensors deteriorate with age, compounded by infections, etc. So, as we age the system is less sensitive and our balance is off. If someone responds by moving less, there is less challenge to the balance system, and it deteriorates further. A vicious circle. You can interrupt this cycle by challenging the balance system. It wont restore the lost sensors, but it will help to fine tune the brain circuits responding to the sensors.

We have a brain circuit that is responsible for movement, Why we go from moving fast to moving slow?? Why?

The faster we move, the more we depend on planning ahead and the less we can use formation from the sensory systems. There simply is not enough time. An adaptation is simply to slow down. More time to think.


Alan Leiner

In is article “The Treasure at the bottom of the brain” he refers on how The  cerebral cortex is connected cerebellum by 40 million fibers (40 times more than from the optical nerve). Is it important to have a powerful communication from front to back. Why>

It is important. But we see this all over the brain. For example, the cortex gets virtually all of its sensory information via another brain region called the thalamus. Remarkably, there are 10 times as many connections back, from the cortex to the thalamus, as coming in from the thalamus to cortex.

We don’t really know why. We think that these back and forth connections are important for interpreting information, by filtering out (or eliminating) the information we don’t need.


Genesis of neuronal and glial progenitors in the cerebellar cortex of peripuberal and adult rabbits.

Ponti G, Peretto P, Bonfanti L.

Department of Veterinary Morphophysiology, University of Turin, Grugliasco, Italy.

His conclusions were “This study reveals that adult cerebellar neurogenesis can exist in some mammals. Since rabbits have a longer lifespan than rodents, the protracted neurogenesis within its cerebellar parenchyma could be a suitable model for studying adult nervous tissue permissiveness in mammals”

What do you think? Would it be possible to create new neurons in the cerebellum?

It is not clear for neurons. There is minimal convincing evidence for the cerebellum or cerebral cortex. There is only convincing evidence for parts of the olfactory system and the hippocampus (memory). We do know that glial cells, which provide support for neurons (and out number neurons 10 to 1), are born throughout life and their birth rate can be affected by the activity of nearby nerve cells. I think it is very plausible that we can boost the birth of new glial cells. This can have a very positive affect on neural function.


In theory does every single movement require the same brain activity?

No. Different movements require different patterns of activity. More complex movements will activate different brain structures than simple movements.

In theory you said that my movements could recruit several brain areas. Is that good?

Yes, I think that is the key point. The more areas you recruit, the more areas become activated. It is not just activation, the different areas will need to organize and process this increased activity. The timing of the changes in activity will be important for learning.

(not sure if we would use this but just in case) Could we quote you from this? All in theory…..

In Prevention you quoted “Michael’s exercises require new coordination patterns,” says Martin. “They seem to mix a challenging posture requiring balance together with a limb movement. This may be similar to creating a cognitive reserve by learning a new language later in life, or learning to play a musical instrument. The exercises likely drive more neural activity in more parts of the brain. This can strengthen neural connections in the action systems of the brain. Perhaps, the more you need to think during a complex movement, the more you recruit connections in the cognitive systems of the brain. While speculative, this may be a way for exercises that require you to think about your moves to benefit parts of the brain for memory and for learning facts.”

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