Continuous and lurching traveling pulses in neuronal networks with delay and spatially decaying connectivity.
Proc Natl Acad Sci U S A
; 96(23): 13480-5, 1999 Nov 09.
Article
en En
| MEDLINE
| ID: mdl-10557346
ABSTRACT
Propagation of discharges in cortical and thalamic systems, which is used as a probe for examining network circuitry, is studied by constructing a one-dimensional model of integrate-and-fire neurons that are coupled by excitatory synapses with delay. Each neuron fires only one spike. The velocity and stability of propagating continuous pulses are calculated analytically. Above a certain critical value of the constant delay, these pulses lose stability. Instead, lurching pulses propagate with discontinuous and periodic spatio-temporal characteristics. The parameter regime for which lurching occurs is strongly affected by the footprint (connectivity) shape; bistability may occur with a square footprint shape but not with an exponential footprint shape. For strong synaptic coupling, the velocity of both continuous and lurching pulses increases logarithmically with the synaptic coupling strength g(syn) for an exponential footprint shape, and it is bounded for a step footprint shape. We conclude that the differences in velocity and shape between the front of thalamic spindle waves in vitro and cortical paroxysmal discharges stem from their different effective delay; in thalamic networks, large effective delay between inhibitory neurons arises from their effective interaction via the excitatory cells which display postinhibitory rebound.
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1
Banco de datos:
MEDLINE
Asunto principal:
Red Nerviosa
Tipo de estudio:
Prognostic_studies
Idioma:
En
Año:
1999
Tipo del documento:
Article