"Neuroscientists know a lot about different parts of the brain, but we don't know a lot about how they talk to each other. Recording how neurons are simultaneously communicating with each other in different parts of the brain and studying how the communication changes in different situations is a big step in this field," said Stanley.
The results from the experiments showed that adaptation shifted neural activity from a state in which the animal was good at detecting the presence of a sensory input to a state in which the animal was better at discriminating between sensory inputs. In addition, adaptation enhanced the ability to discriminate between deflections of the whiskers in different angular directions, pointing to a general phenomenon.
"Adaptation differentially influences the thalamus and cortex in a manner that fundamentally changes the nature of information conveyed about whisker motion," explained Stanley. "Our results provide a direct link between the long-observed phenomenon of enhanced sensory performance with adaptation and the underlying neurophysiological representation in the primary sensory cortex."
The thalamus serves as a relay station between the outside world and the cortex. Areas of the cortex receive and process information related to vision, audition and touch from the thalamus.
The study also revealed that information the cortex receives from the thalamus is transformed as it travels through the pathway due to a change in the level of simultaneous firing of neurons in the thalamus. The researchers found that the effect of adaptation on the synchrony of neurons in the thalamus was the key element in the shift between sensory input detection and discrimination.
"There is a switching of the circuit to a different function. The same neurons do two different things and switch quickly, in a matter of seconds or milliseconds, through a change in the
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Georgia Institute of Technology Research News