Potentiation of Ca2+ influx through NMDA channels by action potentials:: a computer model

被引:4
作者
Neville, KR
Lytton, WW
机构
[1] Univ Wisconsin, Neurosci Training Program, Madison, WI 53706 USA
[2] Univ Wisconsin, Dept Neurol, Madison, WI 53706 USA
关键词
action potentials; backpropagation; calcium; dendrites; long-term potentiation; NMDA receptors; pyramidal cells;
D O I
10.1097/00001756-199911260-00045
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
IN pyramidal cells, somatic action potentials can propagate actively back into the apical dendrites and potentiate calcium influx at simultaneously activated glutamatergic synapses, presumably by relieving the voltage-dependent block of NMDA channels. We have used computer simulations to investigate the conditions under which this potentiation will be optimal. We find that a spike with a long duration and limited amplitude (peak of similar to-10 mV) will be most effective. A backpropagating action potential will achieve this form if the dendritic membrane has a low K+ channel density and a modest Na+ channel density (30-70 pS/mu m(2), similar to experimentally observed densities). The relative increase in calcium due to the backpropagating spike will be small, however, unless the accumulated calcium is rapidly removed. (C):1999 Lippincott Williams & Wilkins.
引用
收藏
页码:3711 / 3716
页数:6
相关论文
共 24 条
[1]   REGENERATIVE PROPERTIES OF PYRAMIDAL CELL DENDRITES IN AREA CA1 OF THE RAT HIPPOCAMPUS [J].
ANDREASEN, M ;
LAMBERT, JDC .
JOURNAL OF PHYSIOLOGY-LONDON, 1995, 483 (02) :421-441
[2]  
Banks MI, 1996, J NEUROSCI, V16, P3862
[3]   FREQUENCY-DEPENDENT PROPAGATION OF SODIUM ACTION-POTENTIALS IN DENDRITES OF HIPPOCAMPAL CA1 PYRAMIDAL NEURONS [J].
CALLAWAY, JC ;
ROSS, WN .
JOURNAL OF NEUROPHYSIOLOGY, 1995, 74 (04) :1395-1403
[4]  
Hebb D, 1949, ORG BEHAV
[5]   Ca2+ buffering and action potential-evoked Ca2+ signaling in dendrites of pyramidal neurons [J].
Helmchen, F ;
Imoto, K ;
Sakmann, B .
BIOPHYSICAL JOURNAL, 1996, 70 (02) :1069-1081
[6]   A PROGRAM FOR SIMULATION OF NERVE EQUATIONS WITH BRANCHING GEOMETRIES [J].
HINES, M .
INTERNATIONAL JOURNAL OF BIO-MEDICAL COMPUTING, 1989, 24 (01) :55-68
[7]   K+ channel regulation of signal propagation in dendrites of hippocampal pyramidal neurons [J].
Hoffman, DA ;
Magee, JC ;
Colbert, CM ;
Johnston, D .
NATURE, 1997, 387 (6636) :869-875
[8]  
Hoffman DA, 1998, J NEUROSCI, V18, P3521
[9]   ASSOCIATIVE EPSP-SPIKE POTENTIATION INDUCED BY PAIRING ORTHODROMIC AND ANTIDROMIC STIMULATION IN RAT HIPPOCAMPAL SLICES [J].
JESTER, JM ;
CAMPBELL, LW ;
SEJNOWSKI, TJ .
JOURNAL OF PHYSIOLOGY-LONDON, 1995, 484 (03) :689-705
[10]  
Kamondi A, 1998, J NEUROSCI, V18, P3919