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The Gill Center for Biomolecular Science

Gill Seminars

Previous Speakers

Upcoming Speakers

April 6, 2015
Cheryl Conrad, Ph.D.

Arizona State University

Seminar will be held in Psychology, Room 101 at 4:00 p.m.

Title: Consequences of chronic stress on the brain and behavior: Mechanisms for resilience

Abstract: Chronic or persistent stress is a known risk factor for a multitude of neuropsychiatric conditions that include, but not limited to, post-traumatic stress disorder, major depression, anxiety disorders, and drug addiction/relapse. Moreover, the neurocircuitries and mediators underlying the stress system overlap with brain regions involved in many neuro-psychiatric conditions. Consequently, work using chronic stress in rodent models can provide insight into understanding mechanisms that underlie the vulnerabilities and resilience for brain health. I will describe some of my team’s past research on chronic stress effects on the hippocampus, a brain region that displays great sensitivity and functional plasticity in response to chronic stress. This is the same brain structure that has received attention for its role in guiding navigation, or spatial ability, with Drs. O’Keefe, Moser, and Moser receiving the 2014 Nobel Prize in Physiology or Medicine on their work in this structure. My team’s work has centered on how chronic stress disrupts this navigational (or “spatial”) memory and produces hippocampal dendritic retraction, which compromises neuronal communication. A novel feature of these chronic stress-induced alterations in spatial memory and dendritic morphology is that they can recover in the following weeks after the chronic stress paradigm has ended. I will discuss some new research that unveils some of the mechanisms underlying the recovery process following the termination of chronic stress. Time permitting, additional findings will be discussed that reveal sex differences in how chronic stress influences the brain and behavior, as well as some other work investigating the prefrontal cortex and amygdalar brain regions.

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April 13, 2015
Charles E. Schroeder, Ph.D.

Nathan Kline Institute, Department of Psychiatry, Columbia University College of Physicians and Surgeons

Seminar will be held in Psychology, Room 101 at 4:00 p.m.

Title: Neuronal Mechanisms of Temporal Prediction in Active Sensing

Abstract: Neuronal oscillations reflecting synchronous, rhythmic fluctuation of neuron ensembles between high and low excitability states, dominate ambient activity in the sensory pathways. Because excitability determines the probability that neurons will respond to input, a top-down process like attention can use oscillations as “instruments” to amplify or suppress the brain’s representation of external events. That is, by tuning the frequency and phase of its rhythms to those of behaviorally and/or cognitively-relevant event streams, the brain can use its rhythms to parse event streams and to form internal representations of them. In doing this, the brain is making temporal predictions. I will discuss findings from parallel experiments in humans and non-human primates that outline specific structural and functional components of this temporal prediction mechanism. I will also discuss its possible generalization across temporal scales, as well as motor system contributions to sensory systems’ dynamics.

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November 2, 2015
A. Vania Apkarian, Ph.D.

Northwestern University School of Medicine

Seminar will be held in Psychology, Room 101 at 4:00 p.m.

Title: Transition to chronic pain: Predictors and consequences

Abstract: 1) I will review accumulating evidence regarding brain reorganization with chronic pain. Both human brain imaging studies as well as animal model studies specifically interrogating the role of supraspinal plasticity will be emphasized. The primary take home message is that the grey matter of the neocortex dynamically changes with chronic pain and this reorganization is pain type specific.

2) It is common clinical knowledge that although a very large patient population presents with similar injuries that give rise to pain, only a small minority of them develop chronic pain. Thus the critical question in the field of pain research is: what characteristics differentiate between those that develop chronic pain and the ones who properly recover from their injury into health. I will review the results from the only existing longitudinal brain-imaging based study, where brain anatomical and functional properties were studied as subjects transitioned from acute to chronic pain. One hundred and twenty sub-acute back pain patients (SBP, no back pain for at least one year and persistence of back pain for 4-12 weeks of an intensity of 5/10) were recruited and followed over one year, where repeated brain imaging and pain questionnaire outcomes were collected. Sixty-eight subjects completed the study. Different subgroups of these subjects were analyzed at various phases of the study to examine 1) brain grey matter reorganization and related functional properties, 2) brain white matter properties as predictors of pain chronification, 3) changes in brain activity reflecting back pain in the transition to chronic pain, 4) relationship between smoking and chronic pain. The primary result of these analyses is the important observation that very simple brain parameters accurately predict who will develop chronic pain and who will not. Both anatomical and functional properties seem critical.
 If time permits I will present an overall mechanistic model of the transition to chronic pain that summarizes the results presented in both lectures.

Overall we envision four distinct phases for transition from acute to chronic pain:

  1. Predisposition
  2. Injury or inciting event
  3. Transition
  4. Maintenance

Mechanisms underlying each of these phases are distinct. Phase 2 is primarily determined by nociceptive processes, while phase 1 seems mainly brain dependent,  for chronic back pain.

Reference papers:
Corticostriatal functional connectivity predicts transition to chronic back pain.
Baliki MN, Petre B, Torbey S, Herrmann KM, Huang L, Schnitzer TJ, Fields HL, Apkarian AV.
Nat Neurosci. 2012 Jul 1;15(8):1117-9.

A dynamic network perspective of chronic pain.
Farmer MA, Baliki MN, Apkarian AV.
Neurosci Lett. 2012 Jun 29;520(2):197-203.