An intricate communication network that carries information from the brain to the digestive tract regulates a variety of behaviours, including feeding, mental state, and even some neurological illnesses. However, the technology required to comprehend this "brain-viscera interoceptive signalling" is restricted.
In order to examine those connections, a new device that functions as a multipurpose neural interface is now available. The researchers have demonstrated that they can manipulate the neural circuits in mice that connect the gut and the brain using fibres embedded with various sensors and light sources for optogenetic activation.
"What's fascinating about this is that we now have technology that can influence gut health and actions like feeding. More significantly, we can use optogenetics' millisecond accuracy to access the crosstalk between the gut and the brain in behaving animals, according to Polina Anikeeva, PhD, an MIT professor of materials science and engineering and a member of the McGovern Institute for Brain Research.
The body and the brain are constantly communicating with one another in both directions, according to Anikeeva. "For a very long time, we believed that the brain was a tyrant that dictated everything and sent output into the organs. However, we now know that the brain receives a lot of feedback, and this feedback may be responsible for some of the mental processes that we previously thought were solely under the control of the central nervous system.
Analysing the impulses that travel between the brain and the gastrointestinal nervous system was of interest to Anikeeva. Hormone release and neuronal interaction are two ways that gut sensory cells affect appetite and satiety.
Flexible fibres that can perform a number of tasks and can be placed into the target organs make up the electronic interface. Atharva Sahasrabudhe, a graduate student at MIT, employed thermal drawing to produce the fibres. This technique allowed him to produce polymer filaments that are about as thin as human hair and can contain electrodes and temperature sensors.
Additionally, the filaments contain microfluidic channels that can be used to distribute medications and microscale light-emitting components that can be used to optogenetically stimulate cells. Additionally, the fibres are made to be wirelessly controllable by a temporary attachment to the animal during an experiment using an external control circuit.
The scientists conducted a number of studies using this interface to demonstrate that they could affect behaviour by altering both the gut and the brain.
They first delivered optogenetic stimulation to the brain's ventral tegmental region (VTA), which releases dopamine, using the fibres. The scientists put mice in a cage with three chambers, and when the animals entered a particular compartment, the dopamine neurons were triggered. The mice were more likely to return to that compartment in quest of the dopamine reward after the ensuing dopamine explosion.
The scientists next looked to see if they might trigger such behaviour by affecting the gut. To achieve this, scientists released sucrose using gut fibres, which also stimulated the production of dopamine in the brain and caused the animals to seek out the chamber in which the sucrose had been administered.
You must be logged in to post a comment.