Physiology and Biophysics


PBIO Seminar Series: Brent Doiron, Ph.D. @ HSB G-328
May 17 @ 9:30 am – 10:30 am

New Cortex.  Who dis(inhibition)?


Brent Doiron, PhD
Department of Mathematics
University of Pittsburgh

host: Adrienne Fairhall

seminar abstract:

New Cortex.  Who dis(inhibition)?


It is now clear that the inhibitory circuitry within cortical networks is very complex, with multiple cell types interacting with one another and pyramidal neurons in complicated and cell specific ways.  The theoretical community has been slow to adapt to this new circuit reality, and much of our results are obtained from analysis of simpler recurrent excitatory-inhibitory circuits. Two often cited functional roles of inhibition is to: 1) stabilize the dynamics of recurrently coupled excitatory networks, and 2) enact gain control of excitatory neuron responses to a driving stimulus.  In classic excitatory-inhibitory networks mechanisms that place the network in a high gain state necessarily flirt with network instability.  We analyze how recurrent networks of pyramidal neurons (PN), parvalbumin-expressing (PV), somatostatin-expressing (SOM), and vasoactive intestinal polypeptide-expressing (VIP) interneurons compartmentalize stability and gain control through distinct inhibitory and disinhibitory pathways.  This permits a disassociation of stability and gain control in the circuit.  We further show how PC to SOM connections can be crucial in state dependent gain amplification with a simultaneous decrease of shared variability (noise correlations).  In sum, by expanding the complexity of inhibitory architecture cortical circuits can navigate distinct functional roles of inhibition through a “division of labor” with the inhibitory circuit.  This imparts a robustness to the functional operations of the circuit that is absent in the often fine-tuned reduced excitatory-inhibitory framework.

PBIO Seminar Series: Ariel Rokem @ HSB G-328
May 24 @ 9:30 am – 10:30 am

seminar: T.B.A.

Ariel Rokem, PhD
Senior Data Scientist
eScience Institute, University of Washington

host: Fairhall

PBIO Seminar Series: Nicholas Whitehead @ HSB G-328
May 31 @ 9:30 am – 10:30 am

Simvastatin: unexpected or logical therapy for muscular dystrophy?

Nicholas P Whitehead, Ph.D.

University of Washington

host: Stanley C. Froehner

PBIO Seminar Series: Amy Bastian @ HSB G-328
Jun 7 @ 9:30 am – 10:30 am

Learning and Relearning Movement

Human motor learning depends on a suite of brain mechanisms that are driven by different signals and operate on timescales ranging from minutes to years. Understanding these processes requires identifying how new movement patterns are normally acquired, retained, and generalized, as well as the effects of distinct brain lesions. The lecture focuses on normal and abnormal motor learning and how we can use this information to improve rehabilitation for individuals with neurological damage

Amy Bastian, Ph.D.
Professor of Neuroscience
Johns Hopkins University

Host: John Tuthill