Optogenetic Inhibition of Parvalbumin-Expressing Interneurons
in Mouse Auditory Cortex
Christine Liu, Aldis Weible, Mike Wehr
Institute of Neuroscience, Department of Psychology, University of Oregon, Eugene, OR
QUESTIONS
THE ROLE OF PV+ INTERNEURONS
IN THE DIVERSE CORTEX
Parvalbumin-expressing(PV+)
interneurons represent a
specfic subclass of cortical
inhibitory interneurons.
Their exact functions are
unknown, but selective
silencing of PV+ cells can reveal
their roles within the auditory
cortex.
Are PV+ cells responsible
for gain control? Does
perception change when
PV+ cells are silenced?
STARTLE RESPONSE AT VARYING
PRE-PULSES WITH AND WITHOUT
SILENCING
Laser
Off Off
Laser
On On
BEHAVIORAL APPROACH
Various types of GABAergic inhibitory
interneurons, including PV+ cells, around a
pyramidal cell.
X
Image from Hensch, T. K. (2005) Critical period plasticity in local cortical circuits.
Nature Reviews Neuroscience, (6), 877-888.
X
PRELIMINARY STUDIES:
PHYSIOLOGICAL EFFECTS
Magnitude of startle response reflects
loudness of cue in a pre-pulse inhibition
task.
Laser Off
Laser On (Silenced)
Significance
OPTOGENETIC SILENCING
PV+ interneurons are
hyperpolarized in Arch-PV
transgenic mice upon illumination.
Startle response decreases when PV+ cells
are optically silenced by the laser.
CONCLUSIONS
The silencing of PV+ cells increases perceived
loudness of auditory stimuli.
PV+ cells may be important in the circuits
responsible for gain control.
ACKNOWLEDGEMENTS
When silenced by a laser pulse, the gain control
properties of PV+ cells are revealed; spike rate of
a pyramidal cell increases.
Support came from NIH-1R25HD070817 and CL was
an intern in the NICHD Summer Research Program at
the U of O.
Contact: [email protected]