 |
The Journal of Neuroscience, April 6, 2005, 25(14):3521-3530; doi:10.1523/JNEUROSCI.4746-04.2005
Previous Article | Next Article 
Cellular/Molecular
Dendrodendritic Synaptic Signals in Olfactory Bulb Granule Cells: Local Spine Boost and Global Low-Threshold Spike
Veronica Egger,
Karel Svoboda, and
Zachary F. Mainen
Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
In the mammalian olfactory bulb, axonless granule cells process synaptic input and output reciprocally within large spines. The nature of the calcium signals that underlie the presynaptic and postsynaptic function of these spines is mostly unknown. Using two-photon imaging in acute rat brain slices and glomerular stimulation of mitral/tufted cells, we observed two forms of action potential-independent synaptic Ca2+ signals in granule cell dendrites. Weak activation of mitral/tufted cells produced stochastic Ca2+ transients in individual granule cell spines. These transients were strictly localized to the spine head, indicating a local passive boosting or spine spike. Ca2+ sources for these local synaptic events included NMDA receptors, voltage-dependent calcium channels, and Ca2+-induced Ca2+ release from internal stores. Stronger activation of mitral/tufted cells produced a low-threshold Ca2+ spike (LTS) throughout the granule cell apical dendrite. This global spike was mediated by T-type Ca2+ channels and represents a candidate mechanism for subthreshold lateral inhibition in the olfactory bulb. The coincidence of local input and LTS in the spine resulted in summation of local and global Ca2+ signals, a dendritic computation that could endow granule cells with subthreshold associative plasticity.
Key words: granule cell; olfactory; calcium; imaging; dendrite; dendritic spine; synaptic
Received Nov 19, 2004;
revised January 29, 2005;
accepted February 23, 2005.
This article has been cited by other articles:

|
 |

|
 |
 
V. Egger and O. Stroh
Calcium buffering in rodent olfactory bulb granule cells and mitral cells
J. Physiol.,
September 15, 2009;
587(18):
4467 - 4479.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. S. Ghatpande and A. Gelperin
Presynaptic Muscarinic Receptors Enhance Glutamate Release at the Mitral/Tufted to Granule Cell Dendrodendritic Synapse in the Rat Main Olfactory Bulb
J Neurophysiol,
April 1, 2009;
101(4):
2052 - 2061.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. R. Pugh and I. M. Raman
Mechanisms of Potentiation of Mossy Fiber EPSCs in the Cerebellar Nuclei by Coincident Synaptic Excitation and Inhibition
J. Neurosci.,
October 15, 2008;
28(42):
10549 - 10560.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Tsuno, H. Kashiwadani, and K. Mori
Behavioral State Regulation of Dendrodendritic Synaptic Inhibition in the Olfactory Bulb
J. Neurosci.,
September 10, 2008;
28(37):
9227 - 9238.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
B. L. Bloodgood and B. L. Sabatini
Regulation of synaptic signalling by postsynaptic, non-glutamate receptor ion channels
J. Physiol.,
March 15, 2008;
586(6):
1475 - 1480.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Inoue and B. W. Strowbridge
Transient Activity Induces a Long-Lasting Increase in the Excitability of Olfactory Bulb Interneurons
J Neurophysiol,
January 1, 2008;
99(1):
187 - 199.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. E. Hildebrand, L. S. David, J. Hamid, K. Mulatz, E. Garcia, G. W. Zamponi, and T. P. Snutch
Selective Inhibition of Cav3.3 T-type Calcium Channels by G{alpha}q/11-coupled Muscarinic Acetylcholine Receptors
J. Biol. Chem.,
July 20, 2007;
282(29):
21043 - 21055.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
B.-J. Lin, T.-W. Chen, and D. Schild
Cell type-specific relationships between spiking and [Ca2+]i in neurons of the Xenopus tadpole olfactory bulb
J. Physiol.,
July 1, 2007;
582(1):
163 - 175.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H.-W. Dong, A. Hayar, and M. Ennis
Activation of Group I Metabotropic Glutamate Receptors on Main Olfactory Bulb Granule Cells and Periglomerular Cells Enhances Synaptic Inhibition of Mitral Cells
J. Neurosci.,
May 23, 2007;
27(21):
5654 - 5663.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. B. Castro, K. R. Hovis, and N. N. Urban
Recurrent Dendrodendritic Inhibition of Accessory Olfactory Bulb Mitral Cells Requires Activation of Group I Metabotropic Glutamate Receptors
J. Neurosci.,
May 23, 2007;
27(21):
5664 - 5671.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Balu and B. W. Strowbridge
Opposing Inward and Outward Conductances Regulate Rebound Discharges in Olfactory Mitral Cells
J Neurophysiol,
March 1, 2007;
97(3):
1959 - 1968.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
N. Laaris, A. Puche, and M. Ennis
Complementary Postsynaptic Activity Patterns Elicited in Olfactory Bulb by Stimulation of Mitral/Tufted and Centrifugal Fiber Inputs to Granule Cells
J Neurophysiol,
January 1, 2007;
97(1):
296 - 306.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Heinbockel, N. Laaris, and M. Ennis
Metabotropic Glutamate Receptors in the Main Olfactory Bulb Drive Granule Cell-Mediated Inhibition
J Neurophysiol,
January 1, 2007;
97(1):
858 - 870.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
V. Kapoor and N. N. Urban
Glomerulus-specific, long-latency activity in the olfactory bulb granule cell network.
J. Neurosci.,
November 8, 2006;
26(45):
11709 - 11719.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
B. Bathellier, S. Lagier, P. Faure, and P.-M. Lledo
Circuit Properties Generating Gamma Oscillations in a Network Model of the Olfactory Bulb
J Neurophysiol,
April 1, 2006;
95(4):
2678 - 2691.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
L. J. Blakemore, M. Resasco, M. A. Mercado, and P. Q. Trombley
Evidence for Ca2+-permeable AMPA receptors in the olfactory bulb
Am J Physiol Cell Physiol,
March 1, 2006;
290(3):
C925 - C935.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Zelles, J. D. Boyd, A. B. Hardy, and K. R. Delaney
Branch-Specific Ca2+ Influx from Na+-Dependent Dendritic Spikes in Olfactory Granule Cells
J. Neurosci.,
January 4, 2006;
26(1):
30 - 40.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|