Impact of the activation rate of the hyperpolarization-activated current I-h on the neuronal membrane time constant and synaptic potential duration

Autor(es)

Ceballos, Cesar C. ^{[1, 2]} ; Pena, Rodrigo F. O. ^{[1, 3, 4]} ; Roque, Antonio C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Philosophy Sci & Letters Ribeirao Preto, Dept Phys, Ribeirao Preto, SP - Brazil

^[2] Oregon Hlth & Sci Univ, Vollum Inst, L474, Portland, OR 97201 - USA

^[3] New Jersey Inst Technol, Federated Dept Biol Sci, Newark, NJ 07102 - USA

^[4] Rutgers State Univ, Newark, NJ - USA

• Tipo de documento: Artigo Científico
• Fonte: European Physical Journal-Special Topics; v. 230, n. 14-15, p. 2951-2961, OCT 2021.
• Citações Web of Science: 1

Resumo

The temporal dynamics of membrane voltage changes in neurons is controlled by ionic currents. These currents are characterized by two main properties: conductance and kinetics. The hyperpolarization-activated current (4) strongly modulates subthreshold potential changes by shortening the excitatory postsynaptic potentials and decreasing their temporal summation. Whereas the shortening of the synaptic potentials caused by the I-h conductance is well understood, the role of the I-h kinetics remains unclear. Here, we use a model of the I-h current model with either fast or slow kinetics to determine its influence on the membrane time constant (tau(m)) of a CA1 pyramidal cell model. Our simulation results show that the I-h with fast kinetics decreases tau(m) and attenuates and shortens the excitatory postsynaptic potentials more than the slow I-h. We conclude that the I-h activation kinetics is able to modulate tau(m) and the temporal properties of excitatory postsynaptic potentials (EPSPs) in CA1 pyramidal cells. To elucidate the mechanisms by which I-h kinetics controls tau(m), we propose a new concept called ``time scaling factor{''}. Our main finding is that the I-h kinetics influences tau(m) by modulating the contribution of the I-h derivative conductance to tau(m). (AU)

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• Processo FAPESP: 15/50122-0 - Fenômenos dinâmicos em redes complexas: fundamentos e aplicações
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