Department of Psychology
Assistant Professor of Psychology
Faculty Affiliate, Chronic Brain Injury
Departments of Psychology and Neuroscience
College of Medicine
Research Interests: The Lindquist laboratory explores the neurobiology of learning and memory. His team is particularly interested in understanding the neural circuitry that underlies the acquisition and expression of different forms of Pavlovian conditioning. They are also interested in the mechanisms by which early-life alcohol exposure can disrupt such learning.
Current Research: A primary area of focus concerns the neurotoxic effects of alcohol on the developing brain in a rat model of fetal alcohol syndrome disorders (FASD). Previously they have examined the adverse effects of early ethanol exposure on the cerebellum and eyeblink conditioning.
More recently, researchers have shifted their analyses to alcohol's deleterious effects on forebrain development, particularly the hippocampus and prefrontal cortex. As adults, the FASD rats are impaired in a variety of hippocampal-dependent learning tasks. The team hypothesizes that early ethanol exposure disrupts normal developmental changes in NMDA receptor subunit composition and function. This leads to impaired synaptic plasticity and learning.
Recent work indicates that ethanol-exposed rats are especially impaired when the learning tasks require the bridging of two stimuli in time (trace fear conditioning) or the conjunctive encoding of contextual memories (context fear conditioning). Both rely on NMDA receptors within the amygdala, hippocampus and prefrontal cortex.
Other research studies seek to better understand the bidirectional interaction between emotional (amygdala) and sensori-motor (cerebellum) systems during aversive classical conditioning. Eyeblink conditioning — a simple form of motor learning — involves the repeated presentation of a neutral conditioned stimulus (CS), like light or tone, and aversive unconditioned stimulus (US), like periorbital electrical shock. Across training, the subject comes to emit an adaptively timed eyeblink-conditioned response (CR) in anticipation of the US.
The behavior and neural circuitry of eyeblink conditioning relies on the brainstem and cerebellum and is arguably better understood than any other learning and memory system. Yet it remains unclear how the amygdala — activated by the emotional attributes of the shock — enhances the eyeblink CR acquisition rate.
Recent work from this lab indicates the amygdala can amplify responsiveness to the tone CS in structures upstream of the cerebellum, facilitating motor conditioning. In turn, as eyeblink conditioning proceeds, the cerebellum is proposed to exert "emotional control" over the amygdala and extinguish the now redundant fear responses. Disruption in either system could, potentially, interfere with motor learning (e.g., discrete movements, balance and coordination) or emotional reactivity (e.g., fear, stress and anxiety).
Research Techniques: The Lindquist laboratory uses a variety of neuroscience techniques. These include multiple behavioral assays, survival surgery (lesions and cannulae implants), neuropharmacology (systemic and local drug administration), neurophysiology (extracellular unit recordings), immunocytochemistry (IHC and IF), Western blots and PCR.
Degree: Yale University
Postdoctoral: Indiana University, University of Kansas