|
|
||||||||
Action potential-evoked [Ca2+]i rises in basket cell axons of rat cerebellar slices were studied using two-photon laser scanning microscopy and whole-cell recording, to identify the K+ channels controlling the shape of the axonal action potential.
Whole-cell recordings of Purkinje cell IPSCs were used to screen K+ channel subtypes which could contribute to axonal repolarization.
-Dendrotoxin, 4-aminopyridine, charybdotoxin and tetraethylammonium chloride increased IPSC rate and/or amplitude, whereas iberiotoxin and apamin failed to affect the IPSCs.
The effects of those K+ channel blockers that enhanced transmitter release on the [Ca2+]i rises elicited in basket cell axons by action potentials fell into three groups: 4-aminopyridine strongly increased action potential-evoked [Ca2+]i; tetraethylammonium and charybdotoxin were ineffective alone but augmented the effects of 4-aminopyridine;
-dendrotoxin had no effect.
We conclude that cerebellar basket cells contain at least three pharmacologically distinct K+ channels, which regulate transmitter release through different mechanisms. 4-Aminopyridine-sensitive,
-dendrotoxin-insensitive K+ channels are mainly responsible for repolarization in basket cell presynaptic terminals. K+ channels blocked by charybdotoxin and tetraethylammonium have a minor role in repolarization.
-Dendrotoxin-sensitive channels are not involved in shaping the axonal action potential waveform. The two last types of channels must therefore exert control of synaptic activity through a pathway unrelated to axonal action potential broadening.
This article has been cited by other articles:
![]() |
B. Rossi, G. Maton, and T. Collin Calcium-permeable presynaptic AMPA receptors in cerebellar molecular layer interneurones J. Physiol., November 1, 2008; 586(21): 5129 - 5145. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Orduz and I. Llano Recurrent axon collaterals underlie facilitating synapses between cerebellar Purkinje cells PNAS, November 6, 2007; 104(45): 17831 - 17836. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Mejia-Gervacio and A. Marty Control of interneurone firing pattern by axonal autoreceptors in the juvenile rat cerebellum J. Physiol., February 15, 2006; 571(1): 43 - 55. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Chen, W. Gao, K. C. Reinert, L. S. Popa, C. M. Hendrix, M. E. Ross, and T. J. Ebner Involvement of Kv1 Potassium Channels in Spreading Acidification and Depression in the Cerebellar Cortex J Neurophysiol, August 1, 2005; 94(2): 1287 - 1298. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. M. Goldberg, S. Watanabe, S. Y. Chang, R. H. Joho, Z. J. Huang, C. S. Leonard, and B. Rudy Specific Functions of Synaptically Localized Potassium Channels in Synaptic Transmission at the Neocortical GABAergic Fast-Spiking Cell Synapse J. Neurosci., May 25, 2005; 25(21): 5230 - 5235. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Collin, M. Chat, M. G. Lucas, H. Moreno, P. Racay, B. Schwaller, A. Marty, and I. Llano Developmental Changes in Parvalbumin Regulate Presynaptic Ca2+ Signaling J. Neurosci., January 5, 2005; 25(1): 96 - 107. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Conti, Y. P. Tan, and I. Llano Action Potential-Evoked and Ryanodine-Sensitive Spontaneous Ca2+ Transients at the Presynaptic Terminal of a Developing CNS Inhibitory Synapse J. Neurosci., August 4, 2004; 24(31): 6946 - 6957. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Galante and A. Marty Presynaptic Ryanodine-Sensitive Calcium Stores Contribute to Evoked Neurotransmitter Release at the Basket Cell-Purkinje Cell Synapse J. Neurosci., December 3, 2003; 23(35): 11229 - 11234. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Ishikawa, Y. Nakamura, N. Saitoh, W.-B. Li, S. Iwasaki, and T. Takahashi Distinct Roles of Kv1 and Kv3 Potassium Channels at the Calyx of Held Presynaptic Terminal J. Neurosci., November 12, 2003; 23(32): 10445 - 10453. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Diana and A. Marty Characterization of Depolarization-Induced Suppression of Inhibition Using Paired Interneuron-Purkinje Cell Recordings J. Neurosci., July 2, 2003; 23(13): 5906 - 5918. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. A. Cingolani, M. Gymnopoulos, A. Boccaccio, M. Stocker, and P. Pedarzani Developmental Regulation of Small-Conductance Ca2+-Activated K+ Channel Expression and Function in Rat Purkinje Neurons J. Neurosci., June 1, 2002; 22(11): 4456 - 4467. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Congar, A. Bergevin, and L.-E. Trudeau D2 Receptors Inhibit the Secretory Process Downstream From Calcium Influx in Dopaminergic Neurons: Implication of K+ Channels J Neurophysiol, February 1, 2002; 87(2): 1046 - 1056. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Mann-Metzer and Y. Yarom Jittery Trains Induced by Synaptic-Like Currents in Cerebellar Inhibitory Interneurons J Neurophysiol, January 1, 2002; 87(1): 149 - 156. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Chabbert, J. M. Chambard, A. Sans, and G. Desmadryl Three Types of Depolarization-Activated Potassium Currents in Acutely Isolated Mouse Vestibular Neurons J Neurophysiol, March 1, 2001; 85(3): 1017 - 1026. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Taschenberger and H. von Gersdorff Fine-Tuning an Auditory Synapse for Speed and Fidelity: Developmental Changes in Presynaptic Waveform, EPSC Kinetics, and Synaptic Plasticity J. Neurosci., December 15, 2000; 20(24): 9162 - 9173. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. L. Cox, W. Denk, D. W. Tank, and K. Svoboda Action potentials reliably invade axonal arbors of rat neocortical neurons PNAS, August 6, 2000; (2000) 170278697. [Abstract] [Full Text] |
||||
![]() |
A. P. Southan and B. Robertson Electrophysiological Characterization of Voltage-Gated K+ Currents in Cerebellar Basket and Purkinje Cells: Kv1 and Kv3 Channel Subfamilies Are Present in Basket Cell Nerve Terminals J. Neurosci., January 1, 2000; 20(1): 114 - 122. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Caillard, H. Moreno, B. Schwaller, I. Llano, M. R. Celio, and A. Marty Role of the calcium-binding protein parvalbumin in short-term synaptic plasticity PNAS, November 21, 2000; 97(24): 13372 - 13377. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |