Optogenetics: Controlling The Brain With Light By Karl Deisseroth

“The Human Brain”, by myPerspectives, is an informative article that claims that the brain is a complex organ that is truly impressive. The brain is a key part of the central nervous system, that controls the entire body’s activities, to simple things such as breathing. These actions are fired through neurons, that quickly travel through the spinal cord. Surprisingly, the brain transmits these messages at an unimaginable rate, at 150 miles per hour, through 85 billion cells, called neurons. These neurons can form up to 10,000 synapses, or connections to each other. By itself, the brain can create billions of synapses, which change the structure of the brain every time new information is learned. However, there is still much that scientists

I read the article, “Secrets of the Brain”, found in the February 2014 issue of National Geographic written by Carl Zimmer. I chose this subject because I have been fascinated with the brain and how it works. The research of the brain has been ongoing for many centuries now. The history in this article is interesting. It explained how scientists used to understand the brain and its inner workings. For example, “in the ancient world physicians believed that the brain was made of phlegm. Aristotle looked on it as a refrigerator, cooling of the fiery heart. From his time through the Renaissance, anatomists declared with great authority that our perceptions, emotions, reasoning, and actions were all the result of “animal spirits”—mysterious, unknowable vapors that swirled through cavities in our head and traveled through our bodies.” (Zimmer, p. 38)

The brain is one of the most complex organ in our bodies. To learn about the brain scientists use electrical stimulation. Electrical stimulation is the use of electrical probes to determine functions of the brain. Clinical observation of patients have also helped scientists learn more about the brain. Case studies of different patients such as Phineas Gage have helped to learn about the different functions of the brain and how they work together to perform complex activities. (Barron’s AP Psychology 6th Edition)

Chapter two begins to go in depth about how the brain works and what makes a human tick . It amazes me that an average person could have up to one hundred billion neurons. Chapter two gives insight on the early discoveries of neurons, and the doubt that the brain is composed of individual cells. The discovery was made by Santiago Ramón y Cajal using a newly developed staining technique to show that a small gap separates the tips of one neuron's fibers from the surface of the next neuron thus proving that the brain is similar to the rest of the body in that is contains individual cells. Neurons share common characteristics with animal cells but more look like a spider web network all interlinking, keeping in mind there are around one hundred

Reading minds is something that everyone at some time in their life wants to do. Now, with improved technology, we can. Scientists have started to study the mind of a fruit fly and what they have found is amazing. Scientists have stumbled upon a possible solution to figuring out the brain of a fly, and possibly the mind of a human. Using fluorescent molecules, researchers are “tagging” neurons in the brain of a fruit fly. After “tagging” the neurons in the brain, the flies are exposed to certain situations, like excessive heat. The scientists observe the behavior of the brain’s neurons as the fly is presented with the situation. The scientists are especially interested in a certain point of nervous contact. This point is called a synapses.

Have you ever wondered how you can speak, walk, listen, memorize, read, and feel? How does one organ, weighing three pounds, control everything? This is where neuroscience comes in. I was first introduced to the topic while preparing for the regional Brain Bee during my junior year of high school. I was reading Brain Facts and I was immediately intrigued. I would run to my biology teacher’s classroom right after school so I could receive answers to my many questions. I’ve never before been so excited to learn. I finally found my passion. I no longer ask, “why did the chicken cross the road?” Instead I ask, “why did the action potential cross the optic chiasm?” To get to the other side, of course. If you can't tell by now, I like brains.

“The neuroscience area - which is absolutely in its infancy - is much more important than genetics,” by Leon Kass. Something about the way the brain functions has intrigued me for so long. The simple questions of how we do things, why we do the things we do, why we feel the way we feel, where does this all come from have been the questions that sparked my interest in the human brain. I have chosen Neuroscience as my major and I aspire to become a neurologist.

The authors were trying to achieve a goal that they describe as a major goal in the field of neuroscience. They were looking for some method of reporting electrical activity in neuronal populations, specifically optical reporting. They developed a voltage sensor that they named Accelerated Sensor of Action Potentials 1 or ASAP1. This allows for GFP to be inserted into an extracellular loop of a voltage-sensing domain (VSD) and making fluorescence responsive to membrane potentials. They were looking for ASAP1 to detect a broad spectrum of membrane potentials, ranging from subthreshold to rapid trains of action potentials. For this to be the case they had to have the appropriate brightness, dynamic range and kinetics.

One field of study in the realm of biology that still leaves much to be discovered is neuroscience, more specifically, the neurological pathways and signaling within the brain. While there have been many developments and breakthroughs in identifying areas of activity and neural pathways, there are still many obstacles to overcome and discoveries to be made. The authors of the journal High-fidelity optical reporting of neuronal electrical activity with an ultrafast fluorescent voltage sensor sought to overcome one such obstacle. They understood the potential for fluorescent proteins to be used for visualizing the firing of action potentials throughout neuronal pathways of the brain, but realized that such proteins were unable to accurately record higher frequency signaling across synapses where there was frequent action potential activity. Within this journal, they describe the methods used to produce a new fluorescent protein, accelerated sensor of action potential 1(ASAP1), and the benefits that it can provide to the field of visualizing the activity of action potentials as they propagate through synapses in the brain. They hypothesized that ASAP1 should be able to give definitive fluorescent readings for the activity of action potentials propagating through the brain, even in areas with high frequency activity that have not been measurable before.

Neurons are the rudimentary particles of the nervous system, and they are the body’s rapid electrochemical information system. Every single neuron receives signals through its branching dendrites, and conducts signals through its axons. Some of our axons are enclosed in a myelin sheath, which enables faster transmission of the signal. If the combined received signals exceed a certain minimum threshold, the neuron “fires” a signal, transmitting an electrical impulse, also known as the action potential, down its axon by way of a

In a recent study, researchers report a novel and easy way to hijack the brain’s natural processes. This technique, which involves the fusion protein GFE3, interferes with the inhibitory synapses between neurons resulting in an overall rise in the brain’s electrical activity.

Two experiments were conducted to examined the movement of the planarians toward different light intensities. There are four light intensities, including ambient, high (19 cm), medium (29 cm), and low (43 cm). The hypothesis of the two experiment is that as the light intensity increases, the planarians’ speed increases as well. Generally, planarian brain perceives information from multiple external signals that receive from sensory neurons. The brain will then integrate the information and produce appropriate behaviors in response, such as thermotaxis, phototaxis, or chemotaxis (Inoue, 2015). When planarians were exposed to the ambient light, the brain sent out phototaxis. When the motor neurons received the signal, the planarians would gradually move to different place with dimmer lighting. However, when the intensity of light suddenly changed from ambient lighting to high intensity (19 cm), the planarians immediately changed the behavior and moved much faster which moving from 44.96 sec to 28.04 sec (Table 3) to go from one end to another end. This data indicates that planarian brain send out the same behavior but stronger signals which caused the planarian to move faster. In this case, the neural nervous system received the strong signals from the sensory neuron which generated the strong intensity in graded potential and high frequency in action potential (Campbell, 2010, 1097). The

and the Brain by John J. Ratey, M.D and Eric Hagerman. This paper focuses on a

Although essentially a broad term, the principal technology in optogenetics incorporates two key functions: light-responsive, control tools that can convey a function in the cell and customizable elements for delivering light to cells of interest; personalizing the control tools for use in the cell of interest; and acquiring analyzable data (Boyden, et. al., 2005). Optogenetically controlled systems had their beginnings in neuroscience, where the need to control a certain type of cell without altering others in the brain was the ultimate goal. This was the underlying concern with classic techniques used to obtain neuronal data; electrical stimulation could not be used for the targeting of individual cells, and the use of drugs to alter neuronal functioning is a slow, imprecise method that is potentially toxic to the cells. Fortunately, optical manipulation of neural activity was accomplished through a microbial opsin gene, a light-sensitive protein that allowed the neurons to react to specific wavelengths of light (Boyden, et. al., 2005). This “light-switching” was capable of being tested in freely motile organisms with no harm inflicted to the organism. Success with this particular group of proteins directed the research of optogenetics to the engineering of several variable

Don: What can I make out of this, we found something that may be important. Describes how scientists went from using quantum entanglement for measuring quantum states by putting those electrons into different kinds of monomers. Then, they converted monomers into a polymer, sending the polymer to the brain, they found out that the brains' bio-electricity are affected and can affect quantum states. So, they were doing trials on grounding of the electrons, forcing the patient to use less brain power to do normal tasks. They wanted to make that thing, hmm