| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1Department of Biology, Boston University, Boston, Massachusetts; 2Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut; and 3Department of Anatomy and Neurobiology and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland
Submitted 17 March 2005; accepted in final form 18 May 2005
We investigated the cellular mechanism underlying presynaptic regulation of olfactory receptor neuron (ORN) input to the mouse olfactory bulb using optical-imaging techniques that selectively report activity in the ORN presynaptic terminal. First, we loaded ORNs with calcium-sensitive dye and imaged stimulus-evoked calcium influx in a slice preparation. Single olfactory nerve shocks evoked rapid fluorescence increases that were largely blocked by the N-type calcium channel blocker 
-conotoxin GVIA. Paired shocks revealed a long-lasting suppression of calcium influx with 
40% suppression at 400-ms interstimulus intervals and a recovery time constant of 450 ms. Blocking activation of postsynaptic olfactory bulb neurons with APV/CNQX reduced this suppression. The GABAB receptor agonist baclofen inhibited calcium influx, whereas GABAB antagonists reduced paired-pulse suppression without affecting the response to the conditioning pulse. We also imaged transmitter release directly using a mouse line that expresses synaptopHluorin selectively in ORNs. We found that the relationship between calcium influx and transmitter release was superlinear and that paired-pulse suppression of transmitter release was reduced, but not eliminated, by APV/CNQX and GABAB antagonists. These results demonstrate that primary olfactory input to the CNS can be presynaptically regulated by GABAergic interneurons and show that one major intracellular pathway for this regulation is via the suppression of calcium influx through N-type calcium channels in the presynaptic terminal. This mechanism is unique among primary sensory afferents.
This article has been cited by other articles:
|
|
 |
|
  M. L. Fletcher, A. V. Masurkar, J. Xing, F. Imamura, W. Xiong, S. Nagayama, H. Mutoh, C. A. Greer, T. Knopfel, and W. R. Chen Optical Imaging of Postsynaptic Odor Representation in the Glomerular Layer of the Mouse Olfactory Bulb J Neurophysiol, August 1, 2009; 102(2): 817 - 830. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. Shao, A. C. Puche, E. Kiyokage, G. Szabo, and M. T. Shipley Two GABAergic Intraglomerular Circuits Differentially Regulate Tonic and Phasic Presynaptic Inhibition of Olfactory Nerve Terminals J Neurophysiol, April 1, 2009; 101(4): 1988 - 2001. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. M. Carey, J. V. Verhagen, D. W. Wesson, N. Pirez, and M. Wachowiak Temporal Structure of Receptor Neuron Input to the Olfactory Bulb Imaged in Behaving Rats J Neurophysiol, February 1, 2009; 101(2): 1073 - 1088. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Liu and M. T. Shipley Intrinsic Conductances Actively Shape Excitatory and Inhibitory Postsynaptic Responses in Olfactory Bulb External Tufted Cells J. Neurosci., October 8, 2008; 28(41): 10311 - 10322. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. D. Eyre, M. Antal, and Z. Nusser Distinct Deep Short-Axon Cell Subtypes of the Main Olfactory Bulb Provide Novel Intrabulbar and Extrabulbar GABAergic Connections J. Neurosci., August 13, 2008; 28(33): 8217 - 8229. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Pirez and M. Wachowiak In Vivo Modulation of Sensory Input to the Olfactory Bulb by Tonic and Activity-Dependent Presynaptic Inhibition of Receptor Neurons J. Neurosci., June 18, 2008; 28(25): 6360 - 6371. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Karpuk and A. Hayar Activation of Postsynaptic GABAB Receptors Modulates the Bursting Pattern and Synaptic Activity of Olfactory Bulb Juxtaglomerular Neurons J Neurophysiol, January 1, 2008; 99(1): 308 - 319. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. F. Silbering and C. G. Galizia Processing of Odor Mixtures in the Drosophila Antennal Lobe Reveals both Global Inhibition and Glomerulus-Specific Interactions J. Neurosci., October 31, 2007; 27(44): 11966 - 11977. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Joshi, M. Volkl, G. M. Shepherd, and M. Laska Olfactory Sensitivity for Enantiomers and Their Racemic Mixtures--A Comparative Study in CD-1 Mice and Spider Monkeys Chem Senses, September 1, 2006; 31(7): 655 - 664. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. B. Rubin and T. A. Cleland Dynamical Mechanisms of Odor Processing in Olfactory Bulb Mitral Cells J Neurophysiol, August 1, 2006; 96(2): 555 - 568. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Ennis, M. Zhu, T. Heinbockel, and A. Hayar Olfactory Nerve-Evoked, Metabotropic Glutamate Receptor-Mediated Synaptic Responses in Rat Olfactory Bulb Mitral Cells J Neurophysiol, April 1, 2006; 95(4): 2233 - 2241. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Vucinic, L. B. Cohen, and E. K. Kosmidis Interglomerular Center-Surround Inhibition Shapes Odorant-Evoked Input to the Mouse Olfactory Bulb In Vivo J Neurophysiol, March 1, 2006; 95(3): 1881 - 1887. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Spors, M. Wachowiak, L. B. Cohen, and R. W. Friedrich Temporal Dynamics and Latency Patterns of Receptor Neuron Input to the Olfactory Bulb J. Neurosci., January 25, 2006; 26(4): 1247 - 1259. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
