Neuron as time coherence discriminator
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Abstract
Neuronal excitability under stimuli with a complex time course is investigated on the basis of the numerical solution of the Hodgkin-Huxley equations. Each stimulus is composed of 100–1000 unitary excitatory postsynaptic potentials (uEPSP) that start randomly within a definite time window. Probability of initiating a spike [firing probability, FP(W)] as a function of the window width W is calculated by the Monte Carlo method. FP(W) has a step-like shape: it becomes equal to 1 for small W and almost vanishes as W exceeds some value WS. The role of long-lasting somatic inhibition is analysed. WS depends on the inhibition potential, but the step-like shape of FP is preserved. It is concluded that the capability of multisynaptic stimulation to cause a spike can be expressed in terms of temporal coherence between the synaptic inputs. Namely, the spike is initiated if the temporal coherence between active inputs is above a definite threshold. The threshold value can be effectively regulated by varying the inhibition potential.
Keywords
Coherence Monte Carlo Method Time Window Complex Time Inhibition PotentialPreview
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References
- 1.Abeles M (1982) Role of the cortical neuron: integrator or coincidence detector? Isr J Med Sci 18:83–92Google Scholar
- 2.Abeles M, Bergman H, Margalit E, Vaadia E (1993) Spatio-temporal firing patterns in the frontal cortex of behaving monkeys. J Neurophysiol 70:1629–1643Google Scholar
- 3.Andersen P, Storm J, Wheal HV (1987) Thresholds of action potentials evoked by synapses on the dendrites of pyramidal cells in the rat hippocampus in vitro. J Physiol (Lond) 383:509–526Google Scholar
- 4.Andersen P, Raastad M, Storm JF (1990) Excitatory synaptic integration in hippocampal pyramids and dentate granule cells. Cold Spring Harbor Symp Quant Biol 55:81–86Google Scholar
- 5.Canavier CC, Baxter DA, Clark JW, Byrne JH (1993) Nonlinear dynamics in a model neuron provide a novel mechanism for transient synaptic inputs to produce long-term alterations of postsynaptic activity. J Neurophysiol 69:2252–2257Google Scholar
- 6.Coombs JS, Eccles JC, Fatt P (1955) Excitatory synaptic action in motoneurones. J Physiol (Lond) 130:374–395Google Scholar
- 7.Crick F (1984) Function of the thalamic reticular complex: the search-light hypothesis. Proc Natl Acad Sci USA 81:4586–4590Google Scholar
- 8.Damasio AR (1989a) Concepts in the brain. Mind Lang 4:25–28Google Scholar
- 9.Damasio AR (1989b) The brain binds entities and events by multiregional activation from convergence zones. Neural Comput 1:123–132Google Scholar
- 10.Eckhorn R, Bauer R, Jordan W, Brosch M, Kruse W, Munk M, Reitboeck HJ (1988) Coherent oscillations: a mechanism for feature linking in the visual cortex? Biol Cybern 60:121–130Google Scholar
- 11.Fatt P, Katz B (1951) An analysis of the end-plate potential recorded with an intra-cellular electrode. J Physiol (Lond) 115:320–370Google Scholar
- 12.Fetz EE, Gustafsson B (1983) Relation between shapes of postsynaptic potentials and changes in firing probability of cat motoneurones. J Physiol (Lond) 341:387–410Google Scholar
- 13.Gray CM, Singer W (1989) Stimulus-specific neuronal oscillations in orientation columns of cat visual cortex. Proc Natl Acad Sci USA 86:1698–1702Google Scholar
- 14.Hodgkin AL, Huxley AF (1952) A quantitative description of membrane current and its application to conduction and excitation in nerve. J Physiol (Lond) 117:500–544Google Scholar
- 15.Jack JJB, Redman SJ (1971) The propagation of transient potentials in some linear cable structures. J Physiol (Lond) 215:283–320Google Scholar
- 16.Jaslove SW (1992) The integrative properties of spiny distal dendrites. Neuroscience 47:495–519Google Scholar
- 17.Kirkwood PA, Sears TA (1982) The effect of single afferent impulses on the probability of firing of external intercostal motoneurones in cat. J Physiol (Lond) 322:315–336Google Scholar
- 18.Langmoen IA, Andersen P (1983) Summation of excitatory postsynaptic potentials in hippocampal pyramidal cells. J Neurophysiol 50:1320–1329Google Scholar
- 19.Noble D, Stein RB (1966) The threshold conditions for initiation of action potentials by excitable cells. J Physiol (Lond) 187:129–162Google Scholar
- 20.Redman SJ, Walmsley B (1983a) Amplitude fluctuations in synaptic potentials evoked in cat spinal motoneurones at identified group Ia synapses. J Physiol (Lond) 343:135–145Google Scholar
- 21.Redman SJ, Walmsley B (1983b) The time course of synaptic potentials evoked in cat spinal motoneurones at identified group Ia synapses. J Physiol (Lond) 343:117–133Google Scholar
- 22.Sejnowsky TJ (1986) Open questions about computation in cerebral cortex. In: McClelland JL, Rumelhart DE (eds) Parallel distributed processing. MIT Press, Cambridge Mass, pp 373–389Google Scholar
- 23.Storm JF (1988) Temporal integration by a slowly inactivating K+ current in hippocampal neurons. Nature 336:379–381Google Scholar
- 24.Traub RD, Wong RKS, Miles R, Michelson H (1992) A model of a CA3 hippocampal pyramidal neuron incorporating voltage-clamp data on intrinsic conductances. J Neurophysiol 66:635–650Google Scholar
- 25.Turner DA (1988) Waveform and amplitude characteristics of evoked responses to dendritic stimulation of CA1 guinea-pig pyramidal cells. J Physiol (Lond) 395:419–439Google Scholar