The BRAIN

 

“Why a map, Mom?”

“Well, how do people normally use a map?”

“To get oriented to a place and to use that to find their way around.” Brian thinks for a minute. “So, it’s to understand where neurons are located inside the brain and how they are connected?” He pauses. “But don’t neuroscientists and neurosurgeons already know the locations and the connections?”

“They do but the brain has more than one billion neurons–” his mom says.

“–and several trillion neural connections or roads, you can say. Wait, are the neurotransmitters like roads or like cars? I guess they are like cars.”

His mom smiles. “That’s a close analogy. How do you think they will use the map?”

Brian scratches his chin.

“There are many diseases like Alzheimer’s or Parkinsons that we don’t fully understand,” his mom says. “ Obama’s BRAIN (Brain Research through Advancing Innovative Neurotechnologies) initiative will help them develop tools that can be used to not only map the brain but to understand how the neurons behave. So, it’s not just about creating a more detailed map but it’s also about getting a dynamic view of the stuff that happens in the brain.”

“But, how, how exactly? How will they capture the messages, the path traversed by the neurotransmitters, the messengers of the brain? I mean, that’s not a static thing…”

“Good point. The current studies use fMRI technologies to measure blood flow in specific parts of the brain. This helps them locate the place where neurotransmitters are active.”

“Yes, I know that!”

“Well, the idea of BRAIN is to provide funding to create more sophisticated tools than the fMRI, to see both high-level view of the neurons and their activities and to get a more close-up view—“

“—yeah, I get it.” He says impatiently. “But how is it different than the research already happening?”

“It’s not necessarily different. It’ll build on the existing work and provide additional resources.”

“Ah, so we can learn about the brain faster.”

“Yup.”

“Mom, maybe I can get involved with the BRAIN initiative.”

“Yes, it’s a new thing. So, there will be all types of opportunities if the funding continues. But, first if you have to get qualified by studying neuroscience.”

“Maybe I can become a brain surgeon!”

“Sure, but that means you will learn and use what is already known about the brain. You won’t be making new discoveries. So you won’t be part of BRAIN.”

“So, a neuroscientist then?”

“Yes, or both,” his mom says.

“I can be like Oliver Sacks and be a brain-surgeon and a neuroscientist and a neuroscience writer.”

“Yes, you can be. But first, start exercising your brain on the math homework that’s due tomorrow.”

“Yes  Mom.”


Leena Prasad has a writing portfolio at http://FishRidingABike.com. Links to earlier stories in her monthly column can be found at http://WhoseBrainIsIt.com.

Josh Buchanan, a UC Berkeley graduate, edits this column with an eye on grammar and scientific approach.

References:

  1. Flatow,  Ira, host of President Obama Calls for a BRAIN Initiative, NPR>Science>Research News, April 5, 2013, http://www.npr.org/2013/04/05/176339688/president-obama-calls-for-a-brain-initiative
  2. Neuroscientists Weigh In on Obama’s BRAIN Initiative, Scientific American, May 2, 2013, http://www.scientificamerican.com/article.cfm?id=neuroscientists-weigh-in-obamas-brain-initiative
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mirror mirror

 

topic mirror neurons
region premotor cortex

 

I catch a glimpse of rice and mackerel. She is holding a small piece in-between her thumb and index finger. That’s the authentic way of eating sushi, instead of using chopsticks, I think.

But something else happens in my mind also. My friend and I have just been seated at the Japanese restaurant and have not even looked at the menu. Yet I can almost taste the saba (rice and mackerel) and memories of the sour salty taste make my mouth water. I recall a class lecture from my neuroscience class about mirror neurons.

I am not in the medical profession but studied artificial intelligence as part of my computer science curriculum and later worked in the field. This led to an interest in neuroscience. I use my graduate school training as a journalist to research and explore the brain using what I learned in the introductory neuroscience class as a basic foundation for my journey.

But, this is not a story about me or about sushi. It’s about specific neurons in my brain and in yours – nerve cells that help us connect to each other’s experiences. These neurons are helping to answer questions ranging from feeling hungry while watching someone else eat to feeling the pain of another person to the excitement felt by sport audiences, to learning by watching someone do something.

When I see the saba, the occipital lobe in the back of the brain, processes the visual information. The hippocampus and other parts of the brain retrieve the memory of my own experiences with saba. When I eat the sushi, neurons in the premotor cortex, in the frontal lobe of the brain, enable me to use my fingers to pick up the sushi, bring it to my mouth, and to eat it. Every single action, from the details of the movement of my arms and fingers to the complexities of biting and chewing are handled by the premotor nerve cells.

But if I am not eating the rice and mackerel myself, how is it that my mouth waters as if I can taste the sushi?

As human beings, most of us (excluding people with autism and other brain related diseases) understand empathy. Now, neuroscientists are exploring the coding of empathy within our brain. They have discovered nerve cells which mirror the actions of other people as if we are experiencing what we see. These neurons reside in the premotor cortex along with the premotor neurons which cause motor reflexes. Mirror neurons are a special subset of the premotor neurons and they fire whether we perform an action ourselves or watch others perform the action.

Mirror neurons were discovered by researchers in Parma, Italy in 1992. The scientists had placed electrodes in the brain of a monkey to record and study nerve cell activity by amplifying the sounds made inside the brain when a neuron fires. By chance, they heard the same set of premotor neurons fire off both when the monkey was picking up a peanut and also when the monkey was just watching someone else pick up a peanut. Similar experiments were repeated in monkeys and humans by several follow-up studies conducted by the scientists at Parma and by other scientists around the world.

“I predict that mirror neurons will do for psychology what DNA did for biology,” says Dr. Vilayanur Subramanian Ramachandran, a Professor in the Department of Psychology and the Neurosciences Graduate Program at the University of California, San Diego. In a recent TED lecture entitled “The neurons that shaped civilization” Dr. Ramachandran theorizes that a lot of human learning, and thus evolution, probably speeded up due to mirror neurons.

There are two types of mirror neurons, according to Dr. Christian Keysers, a Professor at Netherlands’ largest medical faculty, the University Medical Center in Groningen. The two types are: strictly congruent and broadly congruent. The strictly congruent neurons are activated for very specific familiar actions. So, when I watch someone eat saba or eat it myself, I’m using strictly congruent neurons. The broadly congruent neurons are activated for actions that might be unfamiliar to me. For example, if I start taking classes in auto repair, I would be using broadly congruent neurons since I do not know much about this topic.

This is an exciting discovery. I found many articles and books and videos on the topic. A lot of the current research is speculation and excitement with a smattering of data to backup the assertions. There are ongoing discussions and experiments to locate mirror neurons in other parts of the brain, in addition to those in the premotor cortex. This trendy subject has been used to explain a range of behavioral phenomena such as language learning, empathy, and lack of emotional intelligence in autism. I look forward to learning more about these neurons as scientists gather more data and develop theories on how the knowledge can be used to understand and fine-tune human behavior. For now, at least I understand why I can taste the sushi by just looking at someone else put it in her mouth.

 


Dr. Nicola Wolfe is a neuroscience consultant for this column. She earned her Ph.D. in Clinical Psychopharmacology from Harvard University and has taught neuroscience courses for over 20 years at various universities.

References:

Ramachandran. Vilayanur Subramanian. Ph.D. The neurons that shaped civilization: VS Ramachandran. TED Talk, January 4, 2010

Keysers, Christian, Ph.D. The Empathic Brain. Social Brain Press, 2011

Do the dance

 

topic Dance
region precuneus

 

“Are you nervous at all?” Sanjay says.

“Excited,” Dana responds to her husband. “Yes, nervous, but with excitement.”

She is having her brain examined today. Well, not exactly examined, but observed by a method called Positron-Emission Tomography (PET scan) which is used to measure changes in cerebral blood flow as a result of brain activity.

“It’s not too late for you to take part in this also, you know.”

“No, no, I’d rather watch.”

Since her decision to participate in the study, they have been reading up on how the brain controls muscular movements.  There is a region towards the back of the brain, appropriately called the posterior parietal cortex, which takes visual information as input and translates it into motor commands. These commands travel through a pipeline of several brain regions to the primary motor cortex, a region that sends neural impulses to the spinal cord resulting in muscle contractions.

Later that afternoon, Dana dresses as if she’s going out dancing.

“Does my primary motor cortex look ready for action?”

“I don’t know but I think my posterior parietal cortex is getting activated.” Her husband winks at her.

She is wearing a flowing jade silk skirt that comes up just above her knee, a silk shirt with just the amount of cleavage that her husband likes, and pencil heels. She has been told that she should prepare for tango dancing as if she was going out to a nightclub and not to a science lab.

Dana and Sanjay have been dancing for many years now. They won an amateur tango contest last year which is what brought them the attention that had led to her participation in this experiment.

When they arrive at the place where the study is to be conducted, she looks around for a dance floor, perhaps a live band. The place looks like an office with a few desks and computers. Through an open door, she sees some large machines. The professor, Dr. D, arrives soon and explains the procedure to her.

“So, I, uh, I’ll be lying down the whole time,” she says. How can they study tango dancing if she will be lying down the entire time? She looks over at Sanjay and he looks as skeptical as she feels.

Dr. D laughs. “I know it sounds very strange.”

“I thought someone said that I will be moving my legs, I mean, I was told to dress for dancing.”

“Yes, yes, the machine is designed so that there is a surface area for moving your legs as if you are dancing. That’s the idea, to watch what’s happening in your brain as your legs move to the music.”

Dana does not look convinced. But she has committed to this, trusts the scientist, and is curious about the outcome. She follows the professor to a room with a large intimidating machine. She has seen these machines on television. People usually lie down in them with their head placed inside the machine. The only difference is that this particular machine actually has an inclined bottom surface where here legs would rest.

“That surface is for you to move your legs,” Dr. D says. “You’ll be listening to tango music through headsets.”

As Dana moves her legs in rhythm to the tango music, sensory organs in her leg muscles will pass on data to the brain’ in terms of the location and orientation of her muscles. The brain will use this information to update the motor commands that it sends back to the muscles. Scientists understand the neural mechanisms of basic motor functions. They are curious, however, to observe how these same mechanisms scale up to handle the complexity of the motions of dance.

In a study at the University of Texas Health Science Center at San Antonio, scientists used PET scans to observe the brains of five male and five female tango dancers in an experiment that occurred as described for the fictional character Dana.

Once Dana is lying inside the scanner with her head immobilized, she is asked to execute the basic salida step of the Argentine tango as she hears the music through her headset. By restricting the legs to motions where the body could not actually move in space, the scientist were able to limit the study to the exact movement of the leg muscles without having to worry about the extra movements of the entire body moving from one location to another.

Sanjay is not allowed to be in the lab so he is unable to watch the results but the professor explains what he and his colleagues saw in the brains of Dana and the other participants.

“We were able to confirm a hypothesis about the parietal lobe,” he said. “That’s the area in the back part of your head.”

“That’s such a large area,” Dana says. “Was there a specific region that you were observing?”

“Yes, yes, the hypothesis is that the brain contains a representative image of the body in a specific area called the precuneus. This representation helps the precuneus to choreograph the movements of the muscles, with the help of other parts of the brain. Of course, we can’t exactly see the representation in the precuneus but we can see blood flow activity in the area with a PET scan.”

“So more blood flow means more activity?” Sanjay says.

“Yes. And the tango dancing created a high level of activity in this region.”

“What’s name of the region, again?” Dana asks.

“Precuneus. You can google it to see the location and the size.”

“But what’s the point of this study,” Sanjay says. “It’s just curiosity or does it provide some answers?’

“Well, possibly. This area is one of the least studied areas of the brain so the more we know about it, the better we can use the knowledge.”

“We were asked to do the steps with and without music. What was the reason for that?”

“Very good question. That was to subtract the affect of music on the brain and to confirm that the precuneus is still activated.”

As they are driving  home, Dana searches for precuneus on her iPhone and reads out parts of the Wikipedia definition to her husband:

The precuneus is…involved with episodic memory, visuospatial processing, reflections upon self, and aspects of consciousness.

“Precuneus,” Sanjay says. “Sounds like it’s a busy part of the brain.”

“Tango dancing will never be the same for me again.”

“Well, it will be, except now the precuneus will be helping to choreograph the dancing and also be aware of itself while you are dancing.”

 


Please send feedback and suggestions for future columns to leena@fishridingabike.com. Go to WhoseBrainIsIt.com for links to past columns and to FishRidingABike.com for Leena’s writing portfolio. Leena has a journalism degree from Stanford University.

References:

Brown, Steven & Parsons, Lawrence M. “The Neuroscience of Dance.” Scientific American July 2008:78-83. Print.