Noise-induced precursors of tonic-to-bursting transitions in hypothalamic neurons and in a conductance-based model.
The dynamics of neurons is characterized by a variety of different spiking patterns in response to external stimuli. One of the most important transitions in neuronal response patterns is the transition from tonic firing to burst discharges, i.e., when the neuronal activity changes from single spikes to the grouping of spikes. An increased number of interspike-interval sequences of specific temporal correlations was detected in anticipation of temperature induced tonic-to-bursting transitions in both, experimental impulse recordings from hypothalamic brain slices and numerical simulations of a stochastic model. Analysis of the modelling data elucidates that the appearance of such patterns can be related to particular system dynamics in the vicinity of the period-doubling bifurcation. It leads to a nonlinear response on de- and hyperpolarizing perturbations introduced by noise. This explains why such particular patterns can be found as reliable precursors of the neurons' transition to burst discharges.
Institute of Physiology, Neurodynamics Group, University of Marburg, Deutschhaus str. 2, D-35037 Marburg, Germany.
Hans A
HA
Braun
Justus
J
Schwabedal
Mathias
M
Dewald
Christian
C
Finke
Svetlana
S
Postnova
Martin T
MT
Huber
Bastian
B
Wollweber
Horst
H
Schneider
Martin C
MC
Hirsch
Karlheinz
K
Voigt
Ulrike
U
Feudel
Frank
F
Moss
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology*; D002478:Cells, Cultured; D003198:Computer Simulation; D004553:Electric Conductivity; D007031:Hypothalamus / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D015233:Models, Statistical; D009415:Nerve Net / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley