Julianna Maisano
Neuroscience Across the Curriculum
12 October 2015
Christopher Moore’s Lecture, Neocortical Dynamics: Computation Beyond Neurons
On Tuesday, October 6, 2015, Christopher Moore, a Professor of Neuroscience at Brown Univeristy spoke about his research in understanding how dynamic the brain truly is. To do this, Dr. Moore and his research team analyzed cell-type specific activity in 2-photon imaging. By combing multiple levels of electrophysiology imaging and optogenetics with behavior, calcium signals across the cortex are able to be examined. Through the development of new electrophysiological tools, neuronal networks can be mapped, recorded and controlled at distinct times during certain behaviors. During his lecture, Dr. Moore discussed his past and present recent projects on the inner workings of neurons through electrophysiology and hemo-neural dynamics.
To date, Dr. Moore has been working on studies that involve neocortical dynamics in both top-down and bottom-up perception. He noted that during top-down perception, gamma rhythms drive perception, however during bottom-up perception, multi-electrode and optogenetics aid in how things are perceived. To analyze behavior and perception, Dr. Moore analyzed the sensory impact of repeated synchronization of fast-spiking interneurons (FS), top understand the response activity pattern believed to underlie neocortical gamma oscillations (Siegle et al., 2014). Through the use of new electrophysiology systems such as OP-EEG, bioluminescence, and BLOG or GLOG, stimuli that are hard to perceive and require neocortical circuitry, will be able to be analyzed, especially if they are in need of consistent attention and detection (Siegle et al., 2014).
In his lecture, Dr. Moore also spoke of his research concerning the hemo-neural hypothesis. Dr. Moore has hypothesized that hemodynamics, local dilations as in fMRI, drive neural excitability on the time scale of milliseconds to seconds. To test the validity of his theory, Dr. Moore set out to analyze neuro-vascular coupling, the key factors that contribute to vascular disease, and the neuromodulator of informational processing. Local vaso-dilations are used to predict information in the neocortex. The vasculature forms a densely interconnected network in close opposition to the neighboring neurons in which the cells are also found to sit on top of the vasculature. By using fMRI techniques, Dr. Moore is able to stimulate an area of the brain that controls specific movements to analyze increased blood flow to these areas. To add, Dr. Moore has also analyzed hyperemia, to which he defined as an excess of blood in the vessels supplying an organ or other part of the body. Hyperemia does not have a role in regulating metabolism, however, the condition does increase the tendency of cells to over-shoot in oxygen supply, which in some cases enables blood flow to be considered a neuro-modulator (Moore, 2015).
Despite the progress Dr. Moore and his research team have made, there are limitations to the types of research that he and his team are able to conduct. Dr. Moore has experienced challenges in testing the impact of vaso-dilation on neurons in vivo, as the use of anesthesia can be controversial and the use of electrodes for 2-photon calcium imaging can be difficult. To conclude his lecture, Dr. Moore discussed the future of his research. He noted that selective vascular motion is derived from neural activity and that by moving small bodily features such as whiskers we can look directly into the cortex to analyze brain activity.
References
Moore, C. (2015, October 6). Neocortical Dynamics: Computation Beyond Neurons. Lecture.
Siegle, J., Pritchett, D., & Moore, C. (2014). Gamma-range synchronization of fast-spiking
interneurons can enhance detection of tactile stimuli. Nature Neuroscience Nat Neuroscience, 1371-1379.