Chris Moore Lecture
Amina Kureshi
Neuroscience Across the Curriculum
Neuroscientist Chris Moore recently gave a talk on Trinity’s campus about his research on the Hemo-Neural Hypothesis. As stated in the paper he co-wrote (Moore & Cao 2008), Moore describes the phenomena of increased localized blood flow to particular areas of the brain hyperemia, and the correlation of hyperemia to local brain activity is termed functional hyperemia. This increase in blood is not due to rising metabolic demands of the cell. We can see how this makes sense since the metabolic cycle of a cell would only increase activity over a longer period of time than it takes to fire the action potential. In order words, if the increase in blood flow was to provide more support for the cell to produce neurotransmitter, which is made in the cell body the slowly transported to the terminal bouton where it can then be released with the occurrence of an action potential, increase in activity would be a delayed response to hyperemia. However, what we see instead is a nearly instantaneous reaction of the neurons/glial cells to the local hyperemia. In fact, part of Moore’s talk discussed a cell that was imaged in his lab, which wraps around the blood vessel. Therefore, when the blood vessel dilates, it is proposed that mechanoreceptoros on the particular neuron cause immediate depolarization. This would theoretically relay information about local hyperemia to other cells. However, a cell need not be wrapped around the blood vessel in order to be affected by local hyperemia. As Moore himself stated, no soma in the brain is more than 30 microns away from a blood vessel. This is such a close proximity that it cannot be imaged with traditional techniques. The technique which allowed for this type of imaging is known as optogenetics, in which a light-sensitive protein is incorporated into the anatomy of genetically altered mice. This protein depolarizes the cells in response to light stimulus.
The greatest lesson to be learned through Moore’s research is that functional hyperemia, while poorly correlated with metabolic demands, is highly correlated with information processing. In layman terms: where the brain is firing is where the blood is going. It is important to note that correlation is not causation; though it may be that the blood flow increases the activity of the neurons/glial cells, it may also be likely that the neurons or astrocytes drive blood flow as a neuromodulator. One proposed mechanisms of interaction between the neural cells/glial cells and blood flow is via the neuromodulator nitric oxide gas, which might easily pass through the blood-brain barrier. Either way, blood acts as a highway to quickly communicate information long distances within the brain and throughout the body.
Chris Moore’s talk brings up many interesting points about how we see communication in the brain. It is important to have speakers like him come and talk at Trinity, as this type of research challenges our current view and context of neuroscience. That said, there were some major points for improvement in the lecture he presented. Moore seemed to jump from topic to topic, from experiment to experiment, glossing over the methods sections or mentioning it as an afterthought. This caused his lecture to lack flow and cohesion. Instead of using his slides to support the main theme of the talk, each slide stood independently of the others. This may have caused confusion for those in the audience. Perhaps the comprehensive lecture given before the common hour talk, which I was unable to attend, was better setup and more well-taught. However the common hour lectures are open to the entire campus and a non-science major who had not read his article would be like a fish out of water if they had only attended the common hour talk. Keeping these points in mind, if these lecture issues could be remedied, I would recommend Chris Moore to come and lecture at Trinity again.
Reference:
Moore, Christopher I., and Rosa Cao. “The Hemo-Neural Hypothesis: On The Role of Blood Flow in Information Processing.” Journal of Neurophysiology 99 (2008): 2035-047. Web

Julianna Maisano

30 September 2015
Douglas Coutler’s Science for the Greater Good Lecture Reflection
On Thursday, September 24, 2015, Trinity College alumnus Douglas Coutler ’80, kicked off the College’s Science for the Greater Good lecture series. A Professor of Pediatrics, and a member of the Department of Neuroscience at the University of Pennsylvania, Dr. Coutler discussed the research that he as conducted on epilepsy. Dr. Coutler’s research centers on better understanding the cellular and molecular mechanisms that enable epilepsy to develop (University of Pennsylvania, 2015). To begin his lecture, Dr. Coutler expressed that epilepsy simply does not derive from a single source, but rather many sources. In order to understand how the underlying mechanisms for epileptic seizure and the distinct types of stimuli needed to generate these seizures, Dr. Coutler uses many different physiological, functional imaging, anatomical, and molecular techniques to address this disorder (University of Pennsylvania, 2015).
Epilepsy is one of the most common neurological disorders, with the most common symptom presented as a seizure. As the uniform component of epilepsy, seizures occur when there is an abnormal amount of synchronous neuronal activity within the brain. a seizure presents itself externally as numerous uncontrolled jerking movements, as a result of the excessive amounts of synchronous activity (Fisher et al., 2005). Dr. Coutler expressed that while there is no known treatment for the underlying disorder, it is known that the hippocampus is a structure involved in epilepsy. Subsequently, it is also known that those who suffer from epilepsy are at an increased risk for unexpected death.
Through his research on the disorder, Dr. Coutler has discovered that the dentate gyrus plays a key role in understating the mechanisms of epilepsy. By examining activity in the dentate gyrus during a seizure, we are able to assimilate, break down, and discover the network of structures that are involved during a seizure. Dr. Coutler found that during an epileptic seizure, the dentate gyrus amplifies neuronal activity into the hippocampus which is not suppose to be there. Subsequently, the dentate gyrus circuit within the hippocampus falls when apart when someone experiences epilepsy early on in their lives (Coutler, 2015).
While not enough is known about the development of epilepsy to single out a certain trigger stimulus, functional studies of the disorder are necessary in order to understand how the entire epileptic system works. Because neurons do not work in isolation, activity of all parts of the brain during an epileptic seizure must be assessed. Neuronal circuit dynamics can be analyzed using MRI, EEG, and MEG imaging, however MCI and VSD imaging are more effective as they are able detect activity at the smallest cellular level. To conclude his lecture, Dr. Coutler expressed gratitude towards about the benefits of being a Trinity College alumnus. He encouraged the audience to take classes outside of their comfort zone, pursue their interests, and when conducting scientific research to look for rigor and keep a broad approach.

References

Douglas, C. (2015, September 24). Epilepsy. Lecture presented at Science for the Greater Good
Lecture Series.

Fisher, R., Boas, W., Blume, W., Elger, C., Genton, P., Lee, P., & Engel,
J. (2005). Epileptic Seizures and Epilepsy: Definitions Proposed by the International League Against Epilepsy (ILAE) and the International Bureau for Epilepsy (IBE). Epilepsia, 46(4), 470-472.

University of Pennsylvania. (2015). Douglas A. Coulter || Department of Neuroscience || School
of Medicine || University of Pennsylvania. Retrieved from, http://www.med.upenn.edu/apps/faculty/index.php/g309/p10704

After a semester of work, today I said goodbye to a great organization.

This semester, I organized a 400-person annual fundraising event that saw a 30% rise in revenue for an amazing nonprofit.  I have had a great time with BIAC, and I can’t wait for the chance to speak of them fondly in the future!

Thank you, Professor Raskin, for facilitating this experience.  It has opened my eyes to all the wonderful work that BIAC does, the hard work that goes on behind the scenes, and the great people who are involved in brain injury prevention, awareness, and rehabilitation in Connecticut.  I can now say that I know a decent amount about how small nonprofits work and how I can contribute to their goals.