MODELING THE LEECH HEARTBEAT ELEMENTAL OSCILLATOR .1. INTERACTIONS OF INTRINSIC AND SYNAPTIC CURRENTS

被引:77
作者
NADIM, F [1 ]
OLSEN, OH [1 ]
DESCHUTTER, E [1 ]
CALABRESE, RL [1 ]
机构
[1] UNIV ANTWERP,BORN BUNGE FDN,B-2610 ANTWERP,BELGIUM
关键词
CENTRAL PATTERN GENERATOR; HALF-CENTER OSCILLATOR;
D O I
10.1007/BF00961435
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
We have developed a biophysical model of a pair of reciprocally inhibitory interneurons comprising an elemental heartbeat oscillator of the leech. We incorporate various intrinsic and synaptic ionic currents based on voltage-clamp data. Synaptic transmission between the interneurons consists of both a graded and a spike-mediated component. By using maximal conductances as parameters, we have constructed a canonical model whose activity appears close to the real neurons. Oscillations in the model arise from interactions between synaptic and intrinsic currents. The inhibitory synaptic currents hyperpolarize the cell, resulting in activation of a hyperpolarization-activated inward current I-h and the removal of inactivation from regenerative inward currents, These inward currents depolarize the cell to produce spiking and inhibit the opposite cell. Spike-mediated IPSPs in the inhibited neuron cause inactivation of low-threshold Ca++ currents that are responsible for generating the graded synaptic inhibition in the opposite cell, Thus, although the model cells can potentially generate large graded IPSPs, synaptic inhibition during canonical oscillations is dominated by the spike-mediated component.
引用
收藏
页码:215 / 235
页数:21
相关论文
共 24 条
[1]  
ANGSTADT JD, 1989, J NEUROSCI, V9, P2846
[2]  
ANGSTADT JD, 1991, J NEUROSCI, V11, P746
[3]  
ARBAS EA, 1987, J NEUROSCI, V7, P3953
[4]   NEURONAL CONTROL OF SWIMMING LOCOMOTION - ANALYSIS OF THE PTEROPOD MOLLUSK CLIONE AND EMBRYOS OF THE AMPHIBIAN XENOPUS [J].
ARSHAVSKY, YI ;
ORLOVSKY, GN ;
PANCHIN, YV ;
ROBERTS, A ;
SOFFE, SR .
TRENDS IN NEUROSCIENCES, 1993, 16 (06) :227-233
[5]   RECONSTRUCTION OF ACTION POTENTIAL OF VENTRICULAR MYOCARDIAL FIBERS [J].
BEELER, GW ;
REUTER, H .
JOURNAL OF PHYSIOLOGY-LONDON, 1977, 268 (01) :177-210
[6]   MOTOR-PATTERN-GENERATING NETWORKS IN INVERTEBRATES - MODELING OUR WAY TOWARD UNDERSTANDING [J].
CALABRESE, RL ;
DESCHUTTER, E .
TRENDS IN NEUROSCIENCES, 1992, 15 (11) :439-445
[7]  
CALABRESE RL, 1989, PERSPECTIVES NEURAL, P33
[8]  
CALABRESE RL, 1983, S SOC EXP BIOL, V37, P195
[9]  
CONNOR JA, 1971, J PHYSIOL-LONDON, V213, P1
[10]   ALTERNATIVE EQUATIONS FOR THE MOLLUSCAN ION CURRENTS DESCRIBED BY CONNOR AND STEVENS [J].
DESCHUTTER, E .
BRAIN RESEARCH, 1986, 382 (01) :134-138