Brain activity

A new imaging system developed by researchers at MIT has revealed the brain in action for the first time. This, coupled with brain disease models could offer advantages in understanding pathological processes in real time, leading to potential new drugs and treatments for various neurological and mental disorders.

Thanks to the new imaging system, researchers at the Picower Institute for Learning and Memory had an unprecedented look at how genes shape the brain in response to the environment. One of the authors of the study, Kuan Hong Wang explained the significance was that it is the first study to demonstrate the ability to directly visualise the molecular activity of individual neurons in the brain of live animals at a single cell resolution and observe changes in the activity in response to a changing environment.

Although baby animals are born with a handful of neurons tuned to respond to edges of light at specific orientations, the ability to detect these orientations improves with experience. The more the animal is exposed to shapes, objects and light, the better it can perceive them to be. Plasticity, Wang explained is the ability of a neuron or a synapse to change in response to experience. Changes in synaptic strength require rapid protein synthesis, but at the molecular level, little is known about the factors contributing to experience-dependent changes in orientation selectivity.

To investigate this, researchers developed an imaging system in which transparent cranial windows were implanted over the primary visual cortex, allowing researchers to monitor over time the expression of proteins in brains of live mice. To do so, the study exploited two-photon microscopy (called because it uses two infra-red photons to emit fluorescence in tissue), which allows imaging of living tissue up to 1mm deep, enough for researchers to see proteins expressed within individual neurons within the brain.