AMPA autoreceptors drive correlated spiking in olfactory bulb glomeruli.
Information processing in the brain may rely on temporal correlations in spike activity between neurons. Within the olfactory bulb, correlated spiking in output mitral cells could affect the odor code by either binding or amplifying signals from individual odorant receptors. We examined the timing of spike trains in mitral cells of rat olfactory bulb slices. Depolarization of mitral cell pairs elicited spikes that were correlated on a rapid timescale (< or =10 ms) for cells whose primary dendrites projected to the same glomerulus. Correlated spiking was driven by a novel mechanism that depended on electrical coupling at mitral cell primary dendrites; the specific synchronizing signal was a coupled depolarization ( approximately 20 ms) that was mediated by dendritic AMPA autoreceptors. We suggest that glomerulus-specific correlated spiking in mitral cells helps to preserve the fidelity of odor signals that are delivered to the olfactory cortex.
Schoppa
Nathan E
NE
Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97201, USA. schoppan@hotmail.com
Westbrook
Gary L
GL
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D017660:Autoreceptors / Q000502:physiology*; D003712:Dendrites / Q000502:physiology; D004553:Electric Conductivity; D008959:Models, Neurological; D009433:Neural Inhibition / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009830:Olfactory Bulb / Q000166:cytology / Q000502:physiology*; D009833:Olfactory Pathways / Q000166:cytology / Q000502:physiology; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000502:physiology*; D018035:Receptors, Odorant / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D012903:Smell / Q000502:physiology*
D017660:Autoreceptors; D018091:Receptors, AMPA; D018035:Receptors, Odorant