|
|
||||||||
The Journal of Neurophysiology Vol. 83 No. 3 March 2000, pp. 1693-1700
Copyright ©2000 by the American Physiological Society
1Neuroscience Program and 2Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, Florida 33136; and 3Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907
Baccus, Stephen A.,
Brian D. Burrell,
Christie
L. Sahley, and
Kenneth J. Muller.
Action Potential Reflection and Failure at Axon Branch Points
Cause Stepwise Changes in EPSPs in a Neuron Essential for
Learning. J. Neurophysiol. 83: 1693-1700, 2000. In leech mechanosensory neurons, action potentials reverse direction,
or reflect, at central branch points. This process enhances synaptic
transmission from individual axon branches by rapidly activating
synapses twice, thereby producing facilitation. At the same branch
points action potentials may fail to propagate, which can reduce
transmission. It is now shown that presynaptic action potential
reflection and failure under physiological conditions influence
transmission to the same postsynaptic neuron, the S cell. The S cell is
an interneuron essential for a form of nonassociative learning,
sensitization of the whole body shortening reflex. The P to S synapse
has components that appear monosynaptic (termed "direct") and
polysynaptic, both with glutamatergic pharmacology. Reflection at P
cell branch points on average doubled transmission to the S cell,
whereas action potential failure, or conduction block, at the same
branch points decreased it by one-half. Each of two different branch
points affected transmission, indicating that the P to S connection is
spatially distributed around these branch points. This was confirmed by
examining the locations of individual contacts made by the P cell with
the S cell and its electrically coupled partner C cells. These results
show that presynaptic neuronal morphology produces a range of
transmission states at a set of synapses onto a neuron necessary for a
form of learning. Reflection and conduction block are
activity-dependent and are basic properties of action potential
propagation that have been seen in other systems, including axons and
dendrites in the mammalian brain. Individual branch points and the
distribution of synapses around those branch points can substantially
influence neuronal transmission and plasticity.
This article has been cited by other articles:
![]() |
M. G. Cercos, F. F. De-Miguel, and C. Trueta Real-Time Measurements of Synaptic Autoinhibition Produced by Serotonin Release in Cultured Leech Neurons J Neurophysiol, August 1, 2009; 102(2): 1075 - 1085. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. V. Megalou, C. J. Brandon, and W. N. Frost Evidence That the Swim Afferent Neurons of Tritonia diomedea Are Glutamatergic Biol. Bull., April 1, 2009; 216(2): 103 - 112. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. M. Crisp and K. J. Muller A 3-synapse positive feedback loop regulates the excitability of an interneuron critical for sensitization in the leech. J. Neurosci., March 29, 2006; 26(13): 3524 - 3531. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. D. Burrell and C. L. Sahley Serotonin Mediates Learning-Induced Potentiation of Excitability J Neurophysiol, December 1, 2005; 94(6): 4002 - 4010. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Andjelic and V. Torre Calcium Dynamics and Compartmentalization in Leech Neurons J Neurophysiol, December 1, 2005; 94(6): 4430 - 4440. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. L. Moss, A. D. Fuller, C. L. Sahley, and B. D. Burrell Serotonin Modulates Axo-Axonal Coupling Between Neurons Critical for Learning in the Leech J Neurophysiol, October 1, 2005; 94(4): 2575 - 2589. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Calvino, I. R. Iscla, and L. Szczupak Selective Serotonin Reuptake Inhibitors Induce Spontaneous Interneuronal Activity in the Leech Nervous System J Neurophysiol, May 1, 2005; 93(5): 2644 - 2655. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Pinato and J. Midtgaard Dendritic Sodium Spikelets and Low-Threshold Calcium Spikes in Turtle Olfactory Bulb Granule Cells J Neurophysiol, March 1, 2005; 93(3): 1285 - 1294. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. M. S. Weragoda, E. Ferrer, and E. T. Walters Memory-Like Alterations in Aplysia Axons after Nerve Injury or Localized Depolarization J. Neurosci., November 17, 2004; 24(46): 10393 - 10401. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. D. Burrell and C. L. Sahley Multiple Forms of Long-Term Potentiation and Long-Term Depression Converge on a Single Interneuron in the Leech CNS J. Neurosci., April 21, 2004; 24(16): 4011 - 4019. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Gu, Y. N. Jan, and L. Y. Jan A Conserved Domain in Axonal Targeting of Kv1 (Shaker) Voltage-Gated Potassium Channels Science, August 1, 2003; 301(5633): 646 - 649. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. G. Evans, J. Jing, S. C. Rosen, and E. C. Cropper Regulation of Spike Initiation and Propagation in an Aplysia Sensory Neuron: Gating-In via Central Depolarization J. Neurosci., April 1, 2003; 23(7): 2920 - 2931. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Scuri, R. Mozzachiodi, and M. Brunelli Activity-Dependent Increase of the AHP Amplitude in T Sensory Neurons of the Leech J Neurophysiol, November 1, 2002; 88(5): 2490 - 2500. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. D. Burrell, C. L. Sahley, and K. J. Muller Differential Effects of Serotonin Enhance Activity of an Electrically Coupled Neural Network J Neurophysiol, June 1, 2002; 87(6): 2889 - 2895. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Baccus, C. L. Sahley, and K. J. Muller Multiple Sites of Action Potential Initiation Increase Neuronal Firing Rate J Neurophysiol, September 1, 2001; 86(3): 1226 - 1236. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. D. Burrell, C. L. Sahley, and K. J. Muller Non-Associative Learning and Serotonin Induce Similar Bi-Directional Changes in Excitability of a Neuron Critical for Learning in the Medicinal Leech J. Neurosci., February 15, 2001; 21(4): 1401 - 1412. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. W. Wang, W. Denk, J. Flores, and A. Gelperin Initiation and Propagation of Calcium-Dependent Action Potentials in a Coupled Network of Olfactory Interneurons J Neurophysiol, February 1, 2001; 85(2): 977 - 985. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Nolen and P. Johnson Defensive inking in Aplysia spp: multiple episodes of ink secretion and the adaptive use of a limited chemical resource J. Exp. Biol., January 4, 2001; 204(7): 1257 - 1268. [Abstract] [PDF] |
||||
![]() |
J. A. D. Sanchez, Y. Li, and M. D. Kirk Regeneration of Cerebral-Buccal Interneurons and Recovery of Ingestion Buccal Motor Programs in Aplysia After CNS Lesions J Neurophysiol, December 1, 2000; 84(6): 2961 - 2974. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Antic, J. P Wuskell, L. Loew, and D. Zecevic Functional profile of the giant metacerebral neuron of Helix aspersa: temporal and spatial dynamics of electrical activity in situ J. Physiol., August 15, 2000; 527(1): 55 - 69. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |