Our brains exist to allow us to interact adaptively with our environment. At any given moment, we are bombarded with various streams of sensory information, only a small portion of which is relevant for our current behavioral goals. In order for the brain to prioritize specific types of information and link this information to goal-directed motor behaviors, neuronal networks require mechanisms for flexibility – processing and routing signals differently according to different contexts.
The (neo)cortex, the outermost portion of the mammalian brain, is responsible for many of the most complex aspects of mammalian behavior – from perception and motor control to higher cognitive functions. The gateway to the cortex is a subcortical structure called the thalamus. The vast majority of sensory information must be relayed by the thalamus to the cortex for further processing.
The cortex is a massively interconnected network – a panoply of feedforward and feedback connections, such as those connecting the various cortical regions associated with vision (above). The immense connectivity of the cortex offers an anatomical substrate for flexible information processing by providing a multitude of pathways by which neural signals can be routed and combined. What are the mechanisms by which cortical information flow is orchestrated and regulated?
A traditional view of cortical processing is that once sensory information is relayed from the thalamus, this information flows through the cortex via direct synaptic connections between cortical regions (corticocortical connections). However, this “cortico-centric” view neglects a significant portion of the thalamus, specifically the higher-order thalamus. The higher-order thalamus receives most of its driving input not from the sensory periphery, but from the cortex itself. This arrangement suggests that a key role of the higher-order thalamus is to transmit information between cortical regions, and perhaps to dynamically modulate the efficacy of distinct corticocortical pathways. Yet, what kinds of information does the higher-order thalamus send to the cortex? By what synaptic mechanisms? And how does the higher-order thalamus factor into diseases associated with pathological corticocortical communication, such as autism, schizophrenia, and Parkinson’s disease?
The current core focus of our lab is to expand our knowledge of about the synaptic function of higher-order thalamocortical and corticothalamic circuits, determine how these circuits function in cortical sensory representations, cognitive flexibility, and motor function, and how dysfunction of these circuits contributes to neurological and neuropsychiatric disease. Learn more about the specific projects underway in the lab and the techniques we use to address them.