Final Google Hangout March 17, 2016

The Final Google Hangout of the last session based course of Medical Neuroscience (the course will continue in the on-demand format). With Prof. White and Nicholas Janes on Thursday, March 17, 2016.

Maggie Morton, Community Teaching Assistant (CTA) on this session reports:

Introduction Final Hangout

As usual, Dr. White was generous with his time, taking over an hour to answer questions. Before answering questions, Nicholas Janes was invited to give all students a reminder about final deadlines -here’s hoping that all the reminders paid off and all medical neuroscience students have completed all work on time.

This hangout again reflected the range of students that are involved in Medical Neuroscience. Students from Europe, North America, South America and Africa asked questions that reflect where increased knowledge of the brain is directing their thoughts.

This really felt like a final hangout which prompted more than one student to ask where to go next. While answering questions about how to become involved in research and future neuroscience studies, Dr. White said “most roads can lead to the brain” Dr. White further stated that he “welcomes all perspectives to understand the brain and it is a confluence of multiple disciplines”. This hangout was one not to be missed for those approaching neuroscience as scientists from other fields, social scientists, allied health professionals and even musicians. The following topics were discussed:

Hebb’s Postulate and Compensation Injuries

Pia from Sacramento asked, How do muscle groups go offline when you have compensation injury and how does Hebb’s postulate apply? Dr. White was able to answer this question with personal insight following a recent fracture in a bone in his foot. He has been out of an external cast for 3 weeks and found that the cast in itself altered his gait and he has been amazed at how long it took to restore a normal gait in regular walking shoes. He reflected that his nervous system became adapted through mechanisms of Hebbian plasticity to walk in a certain way while wearing the boot. Figuring out how to walk without the boot involves imposing a new wave of plasticity (not undoing plasticity imposed by wearing boot). In this way, central pattern generators and local circuits operating in the spinal cord are returned to re-establish normal gait and correct the compensations learned. Compensations can induce a kind of plasticity in sensory and motor circuits that can have a lasting impact.

Long-term depression

How do you get to the point of long term depression? Each neuron is connected to 2000 other neurons (maybe less in the spinal cord) but only a small handful of inputs are coordinated in their activity, which is reinforcing. There is always long term depression happening, something is always being reinforced and something is being depressed. In the early stages of recovery, we strengthen circuits that were previously providing us with adaptive movement (the neurobiological picture of what does it look like to develop compensatory movement in the first place). Long-term depression happens when many hundreds or thousands of inputs are being reshaped in favor of other hundreds or thousands of inputs that are now being reinforced and made more adaptive. We now have techniques that allow us to watch synapses over time and how dynamic the connections are.

Dr. White’ shared that his affiliation at Duke is with the Physical Therapy Faculty. He feels the future of physiotherapy is learning how to take the power of movement and sensory-motor experience and use it for therapeutic benefit.

Brain research

Can You Reflect on how your feel being part of these amazing times for the research of the brain? (Paula from Columbia) As part of his answer to this question, Dr. White shared that as a young graduate student, he was interested in cardiovascular physiology and through talking to mentors came to realize that the future was the brain, due to its impact on all life and all society. Dr. White recognized that many domains of science require human endeavor and another science or social science might be the next to capture the minds of people around the world. Dr. White stated that this course is a way for him to give back to the field of neuroscience and that the 21st century will be marked by the wonder of what our brain is capable of achieving.

Autism

Virginia, a nurse who is hoping to explore mental health with a research focus sees autism as being a field which is open to the contribution of nursing. She was therefore very interested about Dr. White’s mention of a possible movement based intervention for autism as an area of research. Dr. White answered that there is some evidence from brain imaging that has shown that the underlying issue with autism has to do with brain wiring: there is too much connectivity at certain stages of development and too little in others. Due to wiring then, the premotor cortex and mirror motor network may not function in a typical way in children with autism. Mirror neurons help us understand the intentionality of movement (these neurons help us understand that someone throwing their arms open to us offering an embrace, not violence for example) and there is a connection between the mirror network and social cognition.

The question worthy of research then becomes “if there is plasticity and the underlying condition is related to the motor system, might physical movement be one way to habilitate the condition?” It is interesting to think that there are many motor phenotypes that are associated with autism (such as flapping or rocking) which do not seem purposeful but may, in fact, be a person with autism’s self-shaping their experiences through movement. Physical activity or physical therapy might allow us to intervene in autism if we can better understand the nature of movement in autism and how it can be shaped.

Balance between hemispheres

Virginia then stated that autism is a condition where there are often gross imbalances in the brain between aptitudes (so the same child may be brilliant at math but have motor coordination difficulties). She asked: Do you need to have a balance between the left and right hemispheres or is this junk science? Dr. White stated that any attempt to simplify ASD (Autism Spectrum Disorder) and typical neurodevelopment to left and right hemispheric balance is not useful. What does happen in autism is the specialization of neurons to produce behaviors we value more or less. Dr. White states that we need to expand our view of what typical development is all about to include a greater diversity of neural architectures at all stages of life (especially early stages and end of life). There need to be changes in public policy and education, etc so that we optimize the chances for each individual to flourish in their context but also challenge that context.

Music

Why do you think playing music is so good for your brain? (Virginia)

Dr. White states that a typical functional MRI experiment to find out what stimulus captures as much of the brain and modulates the amplitude of its activity, you will find out that it is likely music. Music engages sensory systems (in raw acoustic signals), emotion, memory and the motor system (when you play an instrument but also when you feel that impulse to move. Very few experiences have that impact on our brain function.

Research process

What advice can you give about the research process and what it is like to take part in research that deals with the brain? (Anna’s question – a clinical psychology student who is taking part in a research and innovation program). As Anna’s focus in on cognitive neuroscience, it seems she will have human subjects. Dr. White suggested Anna affiliate with departments of cognitive neuroscience or psychology. In thinking of how to measure neurological function, Dr. White mentioned electroencephalography and MRI as well as more low-tech measures of byproducts of brain function such as those measuring the visceral motor state (heart rate, breathing rate, galvanic skin conductance response).

The eloquent cortex

Idris, a medical student from Cameroon: This term is one used by neurosurgeons to discuss the important brain areas to preserve in neurosurgery. (one that Dr. White introduced and confessed he dislikes). In reflecting on the time he spends as a medical student in Cameron, Idris reflected that he had seen children after hydrocephalus surgeries on their brains that seem unaffected. He asked if we could remove sections of the cortex and have nothing happen. Dr. White answered that some parts of the brain if damaged will lead to significant morbidity or functional deficits but that there is no part of the brain that is useless. We were reminded of the right temporal lobe, which adds meaning to the language that is understood in Wernicke’s area and produced in Broca’s area in the corresponding areas of the left hemisphere. Damaging these might cause a more subtle deficit. It is important therefore to work with patients to preserve their own personal goals.

Vaccines and autism

Do vaccines cause autism? (Idris from Cameron). International groups of scientists have looked for neurological evidence that vaccines cause autism and the strong conclusion reached is that this is false. While there may be immunological triggers that can affect the developing brain, we do know that vaccines are not a cause of autism.

Eyes and perceptional illusion

Can we trust our eyes? (Idris from Cameron)
Dr. White states we can trust our eyes no more than we can trust any sensory system. Over the past two weeks, this has been debated by vision scientists in the Colour Vision Network where the question has been asked: “what is an illusion and how can we differentiate illusion from perception?” Dr. White says “All of the perception is illusion”. Our brain generates perception, which is validated through interactions with the world. We are surprised when our perception is not validated. In other words, objects reflect protons and the protons enter our eyes, strike our retinas and create neural signals which the brain uses to create the world we see.
We do not see what actually exists as we are only able to see a small band of energy emanating from the world around us (the visual portion of the electromagnetic spectrum), the information which is important for life on this planet. If we processed all the sensory information we take in from all our senses, we would have a very different perception (and might even lose our minds).

Duke’s medical graduate program

Is your program friendly to international medical graduates? (Idris) Although it is challenging for international medical students largely due to finance and restrictions on eligibility for funds, it is not impossible. Dr. White let Idris know of a team of neuroscientists at Duke have begun a residency in Uganda and that there are international partnerships.

Obsessive Compulsive Disorder

Our last question came from Grace who studies human life engineering from Denmark. She wanted to share that she followed a tip shared with another student at the last hangout and has contacted a neuroscientist in Denmark and will enter research working with rehabilitation after hippocampal injuries. Her question is about OCD, where in the brain is it found and how can it be treated?

Two parts of the brain are thought to be involved with obsessive compulsive disorder. The obsessive part of OCD might relate to the medial prefrontal cortex (just below the genu of the corpus callosum). This part of the brain is involved in determining the value we place in our decisions. We suspect that the selection of the behaviors which are a part of obsessive compulsive disorder happens due to dysfunction in the basal ganglia where habits and repetitive behavior are stored and selected, which enforces the habit or repetitive behavior. These parts of the nervous system are interconnected and may be part of a circuit affecting our motivation for these behaviors. There are trials currently where deep brain stimulation is being used to treat OCD by treating that area of the cingulate cortex where the obsessive part of the disorder originates.