Neuroscience

Synthetic Neurobiology: Engineering the Brain.

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The notion of engineering the brain to change the way we think and behave may sound like a practice at home in a nightmarish Orwellian dystopia, but it could one day offer hope to those whose cognitive performance and perhaps even their very sense of self has been hijacked by a disease. When we are healthy, it is easy to take for granted the many biological processes taking place within the brain that influence how we think and behave. The fact that any kind of illness, be it mental or physical, can temporarily alter our personality is widely acknowledged; hence the common phrase upon recovering – feeling like yourself again. For some people, however, these changes can be far from transient. Individuals suffering from Alzheimer’s, Parkinson’s, epilepsy, schizophrenia, and a whole host of other neurological ailments can all experience impaired mental performance due to regions of the brain not functioning correctly. Former engineer turned neuroscientist Ed Boyden is leading a team of scientists who make up the Synthetic Neurobiology Group at the Massachusetts Institute of Technology to develop strategies to tackle these problems. Coming from an engineering background, Boyden imagines the brain like a computer system that can be engineered to optimise performance.

“We want to input information into the cells of the network. In other words, enter information like running software on a computer. And that’s important not only to reveal how the brain works, but also so that we can fix it and repair it. Repair computations that are broken”

Boyden’s team are inventing tools for analysing, engineering, and systematically repairing faulty brain circuits. Although in its early days, Boyden foresees this work being able to restore lost sensory perception, temporarily deactivate regions of the epileptic brain during seizure to prevent the spread of electrical impulses, and reactivate neurons that are abnormally inactive in schizophrenia.

“Since neurons compute using electricity, if we can put molecules into the neurons that can convert light into electricity, then we can shine light or even scan it around to target individual cells and turn them on or off. To do that, we’ve been borrowing tools from the natural world. Because there are lots of critters out there that do photosynthesis or that sense light and they do that by converting light into electricity. So we put those molecules in the neurons and then use light to turn those neurons on or off and thereby dial information into the brain.”

Getting light sensitive molecules into neurons

These molecules, found in organisms such as algae, are proteins that are coded for by the organism’s DNA. Boyden’s team take the specific DNA sequences for these molecules and put them into viral gene therapy vectors in the form of re-engineered viruses. These viruses then deliver the DNA into the nuclei of the neurons and initiate biological mechanisms to create the light sensitive molecules and install them all over the membrane of the cell.

“One of the tricks you have to do is to figure out how to deliver these genes to the cells that you want and not all the other neighbours, and you can do that, you can tweak the viruses so that they hit some cells and not others and there are other tricks you can play as well in order to get light activated cells. This field has now come to be known as optogenetics”

As well as simply activating and deactivating cells within the brain, Boyden’s team have grand ideas for how the techniques they are developing could one day work to augment cognition in individuals suffering from Alzheimer’s, or recovering from stroke.

“One of the things that we think a lot about is a concept that we like to call the brain co-processor: a machine that can connect to the brain, observe the information of the brain, compute the information that needs to be computed, and then enter information back into the brain. You can imagine many practical uses for such a thing, not only for understanding the brain, but imagine in disorders such as Alzheimer’s disease or stroke where large circuits of the brain are lost, how do you replace those functionalities, and of course if you can replace the parts that are lost with parts that are easy to upgrade in the future, that’s always a great design principle for bioengineering.”

For more information click the link for a TED talk on YouTube. Ed Boyden: A light switch for neurons.

Richard Gardner

Driven To Distraction: The Incompatibility Of Our Biology And Technology.

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Regular use of smart phones and tablet devices throughout the day has become increasingly common in our tech-savvy society. The ease at which we can flick between apps for email, calendar, Facebook, Instagram, Pinterest, WhatsApp, Snapchat…, mean that we are often doing many things at once. Whether we are working or socialising, our desire to switch from one activity to the next seems to be a part of our modern multitasking culture. But are we mentally up to the task?

“Our brains are not wired to multitask well” claims Massachusetts Institute of Technology neuroscientist Earl Miller. “When people think they are multitasking they are in fact switching from one task to another very rapidly. Every time they do so there is a cognitive cost”.

Not only does the process of switching attention in the brain require additional fuel (glucose) causing us to tire faster, but it can result in an increase of both the stress hormone cortisol and adrenaline. These hormones can over-stimulate the brain and worsen our mental performance. In a study by Glen Wilson at the University of London, individuals that regularly broke away from what they were doing to answer emails or reply to text messages suffered detrimental cognitive effects comparable with a lack of sleep.

Should we just ignore the sound of a new notification on our phones until after we have finished what we are doing?

This may not be enough. Dr Wilson also found that even just the opportunity to be distracted could worsen performance. Individuals attempting to stay focused on a task whilst aware of an unread email in their inbox suffered a 10 point loss in their effective IQ. Wilson’s study was commissioned by technology firm Hewlett-Packard (HP) who stated that although technology can help productivity users must learn to switch computers and phones off. It is worth noting that this particular study was conducted in 2005 before iPhones and Android devices were even on the market. 10 years’ worth of new technology is now at our fingertips and competing for our attention like needy children.

But why are we so easily distracted?

Focussing our attention on a task is facilitated by regions of the brain that form the prefrontal cortex. When we feel good after completing a task another region of the brain, the nucleus accumbens, receives an influx of the neurotransmitter dopamine. This interaction of dopamine in the nucleus accumbens was once thought to be the cause of our pleasure sensations, but is now widely believed to be involved in forming associations between pleasure and the activity that caused it; motivating us to repeat the behaviour that led to the reward (the nucleus accumbens also appears to be involved in negative stimulus and avoidance behaviour). However there is a problem for us. The prefrontal cortex has a bias towards novel stimulus and we will often be easily distracted by something new within our environment such as a text message or a Facebook notification. When switching attention and completing this new task, the brain receives pleasurable stimulation and the nucleus accumbens once again reinforces the association between the activity and the reward. Therefore, the more we allow ourselves to break away from our main task and engage in these mini-activities the stronger these neural associations become and the more motivated we are to engage in them. Our nucleus accumbens becomes the proverbial devil on our shoulders – ‘Go, on…have a quick read of that text message’. So even though multitasking has been found to be detrimental to our performance we still feel compelled to do it. Thinking that this type of behaviour sounds familiar? That may be because the nucleus accumbens has been found to also play a role in drug and ‘junk’ food addiction. 

Is it time we took control of our tech habit?

There may be good reason to do so as a neuroimaging study by Fadel Zeidan discovered that a region of the brain known as the anterior cingulate cortex, associated with executive-level function such as staying focused on a task, was seen to be active during meditation related anxiety relief. Engaging this ‘central executive mode’ has also been shown to lower the brain’s glucose needs. Perhaps the trick to an optimal mind then is to be more Zen in the office. If a tree falls in the woods and nobody is there to Snapchat it, does it make a sound? For many of us, multitasking has become an almost inescapable part of our working lives. But just don’t expect our ancient biology to be accommodating of this. Frankly, our two hundred thousand year old brain circuitry just doesn’t care.

Richard Gardner