Artículo
D-type K+ current rules the function of electrically coupled neurons in a species-specific fashion
Fecha
2023Registro en:
Dapino, A., Davoine, F. y Curti, S. "D-type K+ current rules the function of electrically coupled neurons in a species-specific fashion". Journal of General Physiology. [en línea]. 2023, vol. 155, no. 9, p. 1-17. DOI: 10.1085/jgp.202313353
0022-1295
10.1085/jgp.202313353
1540-7748
Autor
Dapino, Antonella
Davoine, Federico
Curti, Sebastián
Institución
Resumen
Electrical synapses supported by gap junctions are known to form networks of electrically coupled neurons in many regions of the mammalian brain, where they play relevant functional roles. Yet, how electrical coupling supports sophisticated network operations and the contribution of the intrinsic electrophysiological properties of neurons to these operations remain incompletely understood. Here, a comparative analysis of electrically coupled mesencephalic trigeminal (MesV) neurons uncovered remarkable difference in the operation of these networks in highly related species. While spiking of MesV neurons might support the recruitment of coupled cells in rats, this rarely occurs in mice. Using whole-cell recordings, we determined that the higher efficacy in postsynaptic recruitment in rat’s MesV neurons does not result from coupling strength of larger magnitude, but instead from the higher excitability of coupled neurons. Consistently, MesV neurons from rats present a lower rheobase, more hyperpolarized threshold, as well as a higher ability to generate repetitive discharges, in comparison to their counterparts from mice. This difference in neuronal excitability results from a significantly higher magnitude of the D-type K+ current (ID) in MesV neurons from mice, indicating that the magnitude of this current gates the recruitment of postsynaptic-coupled neurons. Since MesV neurons are primary afferents critically involved in the organization of orofacial behaviors, activation of a coupled partner could support lateral excitation, which by amplifying sensory inputs may significantly contribute to information processing and the organization of motor outputs.