Rutgers study reveals how different parts of the brain interact with each other
Researchers at the Margolis Lab, which is in the Department of Cell Biology and Neuroscience, have discovered a new difference in the behavior of mice when different parts of the brain are stimulated.
“We were interested in understanding how different sensory inputs can affect how mice respond to a particular sensory input or sensory stimulus,” said Christian Lee, the study's lead author and research associate.
The structure of the parts of the brain studied are largely similar between mice and humans, Lee said. The part of the brain that the study focused on was the cortex, which is involved in motor control and transforming sensory input into action.
In the study, researchers found that mice trained to respond to texture tend to respond more when their motor cortex, which is the part of the brain that controls movement, was activated compared to their sensory cortex, which is the part of the brain that receives information from all five senses.
This is one of the first studies to show that different parts of the cortex engage striatal circuitry differently. The striatum is the part of the brain that goes wrong in people with Parkinson’s disease and Huntington’s disease, said David Margolis, the study's senior author and an assistant professor in the Department of Cell Biology and Neuroscience. Thus, the results have implications for new treatments for these disorders.
“You need to understand how all the pieces interact with each other before you can really come up with the best therapy,” Margolis said.
The findings from the study are significant because they suggest that there is both a behavioral and physiological difference in how the striatum takes in information from the sensory cortex and motor cortex, Lee said.
Many people see diseases such as Parkinson’s disease as “something going wrong in a black box,” Margolis said. The lab focuses more on how all the pieces of the box fit together, rather than developing therapies for the diseases themselves.
Future studies will be based on observing the natural behavior of mice to observe the relationships between their brain and behavior, Margolis said. In this study, different parts of the brain were manipulated to see how the mouse responded.
The mice used were roughly half the size of an adult’s cupped hands, with a short white device attached to its head.
This antenna-like structure was surgically installed to deliver light to the mouse’s brain. Using a method called optogenetics, Margolis said light-sensitive proteins were used to activate the mouse’s neurons.
This method is otherwise known as “remote-control” of neurons, since it essentially allows researchers to control the activity of neurons, such as how the brain cells would communicate with each other in a mouse, he said.
Research for optogenetics is typically used to understand how the brain works on a mechanical level. For this study specifically, the lab focused on understanding how groups of neurons work, because they are responsible for the flow of information throughout the brain. For example, the process of looking at a phone involves photons hitting the eye, and then information traveling to the brain to recognize it as a phone.
Margolis said he was personally more interested in how neurons work on a macro level, as opposed to the micro level.
“(What I’m more interested in) is how people interact with the world, how we learn things ... eventually, if we understand enough about how the brain works, then we will have a much better chance of finding treatments and cures for disease,” Margolis said.