GABAergic Circuits Control Input-Spike Coupling in the Piriform Cortex Export

@article{citeulike:3167962, abstract = {Odor coding in mammals is widely believed to involve synchronized gamma frequency (30-70 Hz) oscillations in the first processing structure, the olfactory bulb. How such inputs are read in downstream cortical structures however is not known. Here we used patch-clamp recordings in rat piriform cortex slices to examine cellular mechanisms that shape how the cortex integrates inputs from bulb mitral cells. Electrical stimulation of mitral cell axons in the lateral olfactory tract (LOT) resulted in excitation of pyramidal cells (PCs), which was followed [\~{}]10 ms later by inhibition that was highly reproducible between trials in its onset time. This inhibition was somatic in origin and appeared to be driven through a feedforward mechanism, wherein GABAergic interneurons were directly excited by mitral cell axons. The precise inhibition affected action potential firing in PCs in two distinct ways. First, by abruptly terminating PC excitation, it limited the PC response to each EPSP to exactly one, precisely timed action potential. In addition, inhibition limited the summation of EPSPs across time, such that PCs fired action potentials in strong preference for synchronized inputs arriving in a time window of <5 ms. Both mechanisms would help ensure that PCs respond faithfully and selectively to mitral cell inputs arriving as a synchronized gamma frequency pattern. 10.1523/JNEUROSCI.2385-08.2008}, author = {Luna, Victor M. and Schoppa, Nathan E.}, citeulike-article-id = {3167962}, citeulike-linkout-0 = {http://dx.doi.org/10.1523/JNEUROSCI.2385-08.2008}, citeulike-linkout-1 = {http://www.jneurosci.org/content/28/35/8851.abstract}, citeulike-linkout-2 = {http://www.jneurosci.org/content/28/35/8851.full.pdf}, citeulike-linkout-3 = {http://www.jneurosci.org/cgi/content/abstract/28/35/8851}, citeulike-linkout-4 = {http://view.ncbi.nlm.nih.gov/pubmed/18753387}, citeulike-linkout-5 = {http://www.hubmed.org/display.cgi?uids=18753387}, day = {27}, doi = {10.1523/JNEUROSCI.2385-08.2008}, issn = {1529-2401}, journal = {J. Neurosci.}, keywords = {gamma, inhibition, olfactory, piriform, rodent, synchrony}, month = {August}, number = {35}, pages = {8851--8859}, posted-at = {2008-08-27 20:01:39}, priority = {2}, title = {GABAergic Circuits Control Input-Spike Coupling in the Piriform Cortex}, url = {http://dx.doi.org/10.1523/JNEUROSCI.2385-08.2008}, volume = {28}, year = {2008} }

TY - JOUR ID - citeulike:3167962 L3 - citeulike-article-id:3167962 N2 - Odor coding in mammals is widely believed to involve synchronized gamma frequency (30-70 Hz) oscillations in the first processing structure, the olfactory bulb. How such inputs are read in downstream cortical structures however is not known. Here we used patch-clamp recordings in rat piriform cortex slices to examine cellular mechanisms that shape how the cortex integrates inputs from bulb mitral cells. Electrical stimulation of mitral cell axons in the lateral olfactory tract (LOT) resulted in excitation of pyramidal cells (PCs), which was followed [~]10 ms later by inhibition that was highly reproducible between trials in its onset time. This inhibition was somatic in origin and appeared to be driven through a feedforward mechanism, wherein GABAergic interneurons were directly excited by mitral cell axons. The precise inhibition affected action potential firing in PCs in two distinct ways. First, by abruptly terminating PC excitation, it limited the PC response to each EPSP to exactly one, precisely timed action potential. In addition, inhibition limited the summation of EPSPs across time, such that PCs fired action potentials in strong preference for synchronized inputs arriving in a time window of <5 ms. Both mechanisms would help ensure that PCs respond faithfully and selectively to mitral cell inputs arriving as a synchronized gamma frequency pattern. 10.1523/JNEUROSCI.2385-08.2008 IS - 35 JF - J. Neurosci. SN - 1529-2401 EP - 8859 TI - GABAergic Circuits Control Input-Spike Coupling in the Piriform Cortex VL - 28 SP - 8851 KW - gamma KW - inhibition KW - olfactory KW - piriform KW - rodent KW - synchrony AU - Luna, Victor AU - Schoppa, Nathan PY - 2008/08/27/ UR - http://dx.doi.org/10.1523/JNEUROSCI.2385-08.2008 ER -