[Abstract Title]. - Society for Neuroscience

indicative of reduced postsynaptic receptor sensitivity to glutamate transmission. ATPA, a
kainate receptor agonist, mimics kainate action both pre- and post-synaptically. Domoic acid, a
quisqualate receptor antagonist, blocks the postsynaptic receptors without depolarizing the
muscle, which supports earlier findings of the muscle containing quisqualate subtype receptors.
No effects are seen on the frequency of spontaneous events in low concentration of domoic acid
which causes a 50% reduction in quantal amplitude. The results suggest a kainate pre-synaptic
auto-inhibitory feedback on evoked release. The feedback could be partly responsible for the
rapid depression with evoked high quantal release and facilitation with evoked low quantal
release during repetitive stimulation. The mechanism of action within the presynaptic terminal
remains to be elucidated. The mild direct postsynaptic action of kainate is likely due to partial
antagonist action on the quisqualate receptors.
Disclosures: J. Lee , None; D.M. Bhatt, None; D.M. Bhatt, None; W. Chung, None; N. Lee,
None; R.L. Cooper, None.
Poster
237. Synaptic Integration II
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 237.10/D35
Topic: B.07.c. Synaptic integration
Support: 1R21 NS056124-01A1
RO1 MH065924
RO1 AA010983
Title: Concentration-dependent dopamine modulation of recurrent synaptic activity and
enhancement of signal-to-noise ratio in the prefrontal cortex
Authors: *S. KROENER 1 , P. E. M. PHILLIPS 2 , L. J. CHANDLER 1 , J. K. SEAMANS 3 ;
1 Neurosciences, Med. Univ. South Carolina, Charleston, SC; 2 Dept. of Psychiatry & Behavioral
Sci., Univ. of Washington, Seattle, WA; 3 Dept of Psychiatry and Brain Res. Ctr., Univ. of British
Columbia, Vancouver, BC, Canada
Abstract: The membrane potential of cortical neurons periodically shifts from a hyperpolarized
down-state into a depolarized up-state which shapes synaptic integration and action potential
generation. In the prefrontal cortex (PFC) the recurrent network activity that sustains the up-state
may be modulated by dopamine (DA). Here we used organotypic co-cultures consisting of slices