In the search for new drug therapies for psychiatric illness, the old view that “the brain is a soup” should no longer apply. It would be better if it was considered “a tangled mess of wires”, according to one of the world’s leading young neuroscientists.
The search for new interventions should focus on which wire to change rather than on "mass disconnection", Prof Kay Tye of Massachusetts Institute of Technology told the Schrödinger at 75 conference on the future of biology.
Current treatments lacked the necessary precision and in her opinion caused too many undesirable side effects.
How does the brain know if something it is sensing is good or bad? That may seem like a simple question, but solving this mystery was critical to human survival, and to identifying what is happening when psychiatric illness occurs, she said.
The immediate follow-on to that question was to look at how unimportant information is filtered out. If it’s a good or bad stimulus, the decision has then to be taken: “Do we want to ‘avoid’ or to ‘approach’.”
In the context of animal survival, “reward seeking is inherently risky . . . it’s is a good insurance policy to prime escape [from a predator],” she added.
Prof Tye outlined cutting-edge methodologies that are emerging to interrogate brain circuitry, which focus on positive and negative emotion in both innate and learned behaviour – and on “how we attach value” to experiences.
The processing of emotions was mainly conducted by the amygdala in the brain’s hemispheres, while experiments on fear and reward conditioning in rodents were revealing what emotional response/decision is being taken.
Light signals
This was achieved using “optogenetics”, a technique in which genes for light-sensitive proteins are introduced into specific types of brain cells to monitor and control their activity precisely using light signals.
To adopt a political metaphor, she said there was a majority vote for a given behaviour as other parts of the brain also had an influence. “Not everyone agrees who should be president. [As in the US] some exert more influence than others; like an electoral college.”
Work on “the circuitry of emotion” emerging from modern techniques has enabled brain research to be conducted at an unprecedented pace. These efforts were coming to fruition in understanding the basis of motivation and emotion, she said.
There was some controversy in her field on the issue of whether animals feel emotion in the same way humans do, she noted.
She juxtaposed two photographs on the screen at the National Concert Hall – one the famous picture of the "chuckle brothers", politicians Martin McGuinness and Ian Paisley, sharing a funny moment; the other of two jovial gorillas seemingly responding in similar way.
Prof Tye stressed, however, it was not possible to say that animals experience emotion in the same way as humans. Moreover, people responded differently to the same stimuli. The sound of gunshot was likely to prompt a rush of excitement in a track athlete, but for a war veteran it may be cause for fear or panic, she said.
She hoped in the future to be build better computational models to help identify what’s happens in the brain in response to stimuli and where information is decoded. In addition, she wanted to examine how the brain works in social groups and when people are alone.
