Skip to main content

IASP Pain Research Forum Seminar: The Parabrachial Complex as a Nexus of Aversive Behaviors

Thank you

Thank you for attending today's seminar. We hope you enjoyed our event.


If you have registered for this webinar, please ensure you are logged in before proceeding to the live webinar. The log in appears in the top right corner. You will see your name displayed if you are already logged in.

  • PRF webinars are a complimentary IASP member benefit. If you are an IASP member, please log in using your IASP credentials, and register for this webinar for free.
  • If you are a nonmember and would like to access the webinar, the fee is USD $25. Please click “Add to Cart” to pay the fee and register. You will be asked to create a nonmember IASP account. If interested in joining IASP as a member, information on joining is included in the “Become an IASP Member” tab above. Questions about IASP membership can be directed to

The IASP Pain Research Forum hosted a seminar with Asaf Keller, PhD, University of Maryland School of Medicine, USA.

A Q&A session moderated by Alexander Chesler, PhD, NIH, USA, followed the presentation. A recording is now available.

Here is an abstract from Dr. Keller:
This seminar will review the role of the parabrachial complex (PB) in processing interoceptive and exteroceptive inputs and in guiding aversion, avoidance and arousal. These functions are related to autonomic control, ingestive behaviors and gustation, sleep, and pain. This seminar will compare the anatomical and functional features of the spino-parabrachial and spino-thalamic pathways, and their distinct roles in acute and chronic pain.

In chronic pain, the activity of PB neurons in markedly amplified, and they display distinctive after-discharges (ADs) – responses that far outlast the stimuli that evoke them. This seminar will discuss the causal role of ADs in chronic pain, and the mechanisms responsible for their generation. New data suggests that after-discharges promote the release of calcitonin gene-related peptide (CGRP) from terminals of PB neurons in the central nucleus of the amygdala (CeA), to drive the potentiation of these CeA neurons. The reciprocal pathway, from the CeA to PB, is also causally involved in chronic pain, in that GABAergic inputs from CeA to PB neurons are suppressed in chronic pain. This seminar will highlight that many deficiencies in our understanding of the functions of the PB. These deficiencies notwithstanding, this seminar will argue that the PB is a key nexus of aversive behaviors.


  • Asaf Keller, PhD, University of Maryland School of Medicine

    Asaf Keller, PhD, completed studies with Ed White at Ben Gurion University in Israel, and his PhD dissertation focused on studying the ultrastructure of cortical circuits. He took a (perpetual) leave of absence from the MD/PhD program to accept a postdoctoral fellowship with the late Hiroshi Asanuma at The Rockefeller University in New York, where he was trained in neurophysiology, and studied use-dependent plasticity in cortical circuits. Dr. Keller's first faculty position (1992) was at Uniformed Services University in Bethesda, MD. He joined the Department of Anatomy & Neurobiology at University of Maryland School of Medicine in Baltimore in 1995, and is now the department chairman.

    Dr. Keller was introduced to pain research in the early 2000s by his students, after they made a coincidental finding while studying how the activity of thalamic neurons is regulated by inhibition. Since then, his work has focused on brain circuits involved in addiction, chronic pain and affective disorders. He is particularly interested in the role of descending pain modulatory pathways, and in reward pathways—involving the thalamus, neocortex, parabrachial nucleus, rostroventral medulla and related structures—in the affective components of pain, and in drug addiction. He is deeply committed to supporting young scientists, especially from diverse backgrounds.

  • Alexander Chesler, PhD, National Center for Complementary and Integrative Health (NCCIH), NIH

    Alexander Chesler, PhD, is a Senior Investigator at the National Institutes of Health (NIH) where he heads the Section on Sensory Cells and Circuits in the National Center for Complementary and Integrative Health (NCCIH). Dr. Chesler received his PhD from Columbia University where, in the laboratory of Dr. Stuart Firestein, he focused on the function and development of olfactory sensory neurons. He did his postdoctoral training in the laboratory of Dr. David Julius at the University of California, San Francisco, where he combined physiological, anatomical, and behavioral approaches to study the pharmacology of somatosensory neurons. He was recruited to NIH in 2013 as a Stadtman Investigator and became a senior investigator in 2020. His laboratory employs multidisciplinary approaches to study how sensory stimuli, such as temperature, touch, and environmental irritants, are detected and encoded by the somatosensory system in mice and humans. His research seeks to uncover the basis by which some stimuli are perceived as innocuous while others are perceived as noxious and how these distinctions are modulated by physiological state or prior experience.

Receive access to this IASP Pain Research Forum seminar with IASP membership. Become a member by clicking here.
August 31, 2021
Tue 12:00 PM EDT

Duration 1H 0M

This live web event has ended.

Event support