The neurons in the
cortex are dyed red and the axons in the higher-order thalamus are
shown in green.
(Picture: R. Mease, M. Metz, A. Groh / Cell Reports,
10.1016/j.celrep.2015.12.026,
modified, licensed
under CC BY-NC-ND 4.0)
(January 21, 2016) Every
day, we constantly absorb information through our sensory organs, which the
brain then needs to process correctly. The information initially reaches the
main relay center, the thalamus, and then travels to the cerebral cortex. The
neurons in the so-called higher-order thalamus form the connecting lines
between both areas of the brain. Prior to this, their role in sensory
processing was unknown. Scientists at the Technical University of Munich (TUM)
have now shown for the first time in an animal model that they enhance and
temporarily store sensory information.
The thalamus is essentially the size of two walnuts and is
located in the middle of the brain. All sensory perceptions converge here
first. As the main relay center, it therefore needs to reconcile the flood of
incoming information and the brain's limited computing power. But how does the
thalamus do this? How does it signal to the cortex within milliseconds which
information is important and needs to be evaluated there and brought to the
conscious mind?
Animal model for
researching sensory stimuli
The processes in the neurons at the transition point between
the thalamus and the cortex are particularly interesting for neuroscientists
like Dr. Alexander Groh at the Institute of Neuroscience and the Department of
Neurosurgery at TUM. “Very little is still known about the role and the effects
of this region, described as the higher-order thalamus. It is, however,
extremely important, as the neurons there develop contacts with numerous areas
in the cortex and potentially affect these,” explains Alexander Groh, who
headed up the study.