Santiago Jaramillo

Assistant Professor, Department of Biology
Member, ION

Office:
215 LISB
541-346-5207

 

Research Interests: Neuronal circuits that mediate behavioral flexibility and attention; auditory coding; neural computation

Overview: We study the neural circuits that mediate auditory cognition. Our goal is to understand how we assign meaning to sounds, how we attend to sounds or ignore them, how we remember them, and how disorders of the brain can affect these processes.
Of particular interest is how our responses to sounds can change depending on context, a phenomenon called behavioral flexibility. Behaving appropriately after changes in context requires that organisms rapidly modify their expectations, associations between cues and rewards, or attentional state. Our lab investigates these cognitive processes by addressing three questions:

  • What happens to the speed and accuracy of behavioral responses after a change in context?
  • Where in the brain is information selected and re-routed to allow for different interpretations of the same stimulus?
  • How do neural circuits implement this flexibility?

In our experiments, we use tools for monitoring and manipulating neuronal activity of specific cell types in behaving rodents, together with theoretical and computational approaches, to uncover the mechanisms that underlie flexible behaviors.

RECENT PUBLICATIONS

Related Articles

Stable representation of sounds in the posterior striatum during flexible auditory decisions.

Nat Commun. 2018 Apr 18;9(1):1534

Authors: Guo L, Walker WI, Ponvert ND, Penix PL, Jaramillo S

Abstract
The neuronal pathways that link sounds to rewarded actions remain elusive. For instance, it is unclear whether neurons in the posterior tail of the dorsal striatum (which receive direct input from the auditory system) mediate action selection, as other striatal circuits do. Here, we examine the role of posterior striatal neurons in auditory decisions in mice. We find that, in contrast to the anterior dorsal striatum, activation of the posterior striatum does not elicit systematic movement. However, activation of posterior striatal neurons during sound presentation in an auditory discrimination task biases the animals' choices, and transient inactivation of these neurons largely impairs sound discrimination. Moreover, the activity of these neurons during sound presentation reliably encodes stimulus features, but is only minimally influenced by the animals' choices. Our results suggest that posterior striatal neurons play an essential role in auditory decisions, and provides a stable representation of sounds during auditory tasks.

PMID: 29670112 [PubMed - in process]