Thalamus is a brain structure located in the center of the brain in every vertebrate animal including humans. Except for the primary olfactory information thalamus provides almost all spatially and temporally coordinated, fast nerve signals to the cerebral cortex. In other words, no sensory, emotional, movement, arousal, stress or sleep related information directly reach cortical neurons without a thalamic transfer. The cortex is isolated from the environment and rest of the brain without thalamic inputs.
Thalamus project to and receives information from all parts of the cortex. Cortical regions have different functions. Distinct regions are specialized to vision, audition, motor functions, planning, forming memories or personal traits. Despite this heterogeneity the structure of cortical regions is quite homogeneous. As a consequence it is implicitly assumed that the nature of communication between cortical regions and thalamus is also homogeneous. Thus, the first major objective of the project is to study how cortical regions specialized to different functions communicate with the thalamus.
In the second part of the project, we address how stress can have lasting consequences on cortical activity and behavior and what role thalamus can play in this project. In this part of the project we focused on a specific thalamic nucleus called paraventricular thalamic nucleus, PVT in short. We examined what role this nucleus play in normal arousal when we wake up from sleep and what role it plays after a stressful situation when behavior can persistently changes.
Finally, we need to use mouse models in which specific regions or cell types can be selectively studied, the effect of their activation, inactivation on the activity of other neurons or on the behavior can be investigated. Thus the third major objective is to compare the organization of human and rodent thalamus.
