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Traits of criticality in membrane potential fluctuations of pyramidal neurons in the CA 1 region of rat hippocampus
Author(s) -
Kosmidis Efstratios K.,
Contoyiannis Yiannis F.,
Papatheodoropoulos Costas,
Diakonos Fotios K.
Publication year - 2018
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.14117
Subject(s) - stimulus (psychology) , neuroscience , bursting , physics , amplitude , criticality , neuron , critical point (mathematics) , excitatory postsynaptic potential , membrane potential , statistical physics , nerve net , inhibitory postsynaptic potential , biophysics , biology , mathematics , psychology , quantum mechanics , mathematical analysis , nuclear physics , psychotherapist
Evidence that neural circuits are operating near criticality has been provided at various levels of brain organisation with a presumed role in maximising information processing and multiscale activity association. Criticality has been linked to excitation at both the single‐cell and network levels, as action potential generation marks an obvious phase transition from a resting to an excitable state. Using in vitro intracellular recordings, we examine irregular, small amplitude membrane potential fluctuations from CA 1 pyramidal neurons of Wistar male rats. We show that these fluctuations, confounded with noise, carry information relevant to the neuronal state. The underlying dynamics exhibit intermittent characteristics shown to describe the temporal fluctuations of the order parameter of a macroscopic system at its critical point even in the absence of firing. An externally applied stimulus serves as the control parameter, driving the system in and out of its critical state. Based on our experimental observations we calculate the equivalent of the isothermal critical exponent δ h finding a value which depends on the applied stimulus. For each neuron there is a stimulus amplitude for which the critical behaviour becomes most pronounced. The corresponding mean value of δ h in the considered ensemble of neurons is δ h ≈ 1.89, close to theoretical predictions for critical networks. Finally, we show that the firing rate of a neuron decreases exponentially with δ h .