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E Lábos

Publications and source records attributed to E Lábos.

6 recordsLinked to original sources
PubMed1990

On the dynamics of triadic synaptic arrangements: computer experiments with formal neural nets of chaotic units.

Computer simulations were carried out in an attempt to understand the possible operating modes of synaptic triadic arrangements as described in the dorsal lateral geniculate nucleus of the monkey. Small networks of "chaotic" units (piecewise linear internal maps) were used to investigate their performance as ON-gates for the transmission of spikes. "Chaotic" units have advantages over "logic" units because the former are asynchronous, it is possible to simulate temporal summation, and also to adjust subthreshold time-constants. It was demonstrated that ensembles with single delay lines, representing "closely-packed" triads, were hardly capable of realizing reliable and efficient ON-gate operations. Networks with multiple delayed lines, patterned after triads "at a distance" coupled with "closely-packed" triads, were capable of secure ON-gate functions. Such gates were input dependent, becoming reliable only when high frequency bursts were used as the source of activity. Moreover, the ON-gate could be temporarily interrupted by square wave bursts applied to the inhibitory units, a situation resembling electron microscopic observations of interneuron to interneuron synapses in the LGNd.

Computer Simulation↗
PubMed1977

Theoretical considerations of local neuron circuits and their triadic synaptic arrangements (TSA) in subcortical sensory nuclei.

Certain sequential models of the so-called synaptic triadic arrangements (TSA) occurring in sensory nuclei are analyzed. The considerations are addressed mainly to the lateral geniculate body. The model is based on the assumption that the neurons establishing these triads consist of conditionally coupled decision-making subunits. It might be concluded that this and similar arrangements could play a role in the discrimination between stationary and moving retinal inputs and in the detection of temporal correlations in certain input channels.

Animals↗
PubMedDate not supplied

Theorems speaking for the asymmetry of all animal brains.

In random graph theory it has been proved that with the increasing size of a graph, the proportion of the non-symmetric graphs increases and this class becomes the dominant one while the number of symmetric cases turns to be 'negligible'. Thus the asymmetry (AS) is the generic property. Since nervous systems are representable by graphs or better with special digraphs, the networks, it follows that the brains are asymmetric in a strong sense according to which all cells are distinguishable from each other alone by their internal connections. Such a consequence holds perfectly only if a random evolution or generation of neural networks is supposed. Thus apparent symmetries have to come from heavily controlled (i.e. non random) ontogenetic processes. At the present time the possible total cellular heterogeneity of the various nervous systems has still unclear functional implications. In small nervous systems the odd number of neurons alone is neither a sufficient nor a necessary condition of the asymmetry in the outlined sense.

Animals↗