Plateau potentials, caused by persistent inward currents (PICs), are a type of electrical behavior seen in neurons.
Spinal cord
Plateau potentials are of particular importance to spinal cord motor systems.[1] PICs are set up by the influence of descending monoaminergicreticulospinal pathways. Metabotropic neurotransmitters, via monoaminergic input such as 5-HT and norepinephrine, modulate the activity of dendritic L-type Calcium channels that allow a sustained, positive, inward current into the cell. This leads to a lasting depolarisation. In this state, the cell fires action potentials independent of synaptic input. The PICs can be turned off via the activation of high-frequency inhibitory input at which point the cell returns to a resting state.[1]
Plateau potentials are also seen in the cortical,[4][5] and hippocampal pyramidal[6] neurons. Using iontophoretic, or two-photon glutamate uncaging experiments, it has been discovered that these plateau potentials include activities of voltage dependent calcium channels and NMDA receptors.
References
^ abSvirskis, G; Gutman, A; Hounsgaard, J (January 2001). "Electrotonic structure of motoneurons in the spinal cord of the turtle: inferences for the mechanisms of bistability". Journal of Neurophysiology. 85 (1): 391–8. doi:10.1152/jn.2001.85.1.391. PMID11152739.
^Suzuki, T; Kodama, S; Hoshino, C; Izumi, T; Miyakawa, H (August 2008). "A plateau potential mediated by the activation of extrasynaptic NMDA receptors in rat hippocampal CA1 pyramidal neurons". The European Journal of Neuroscience. 28 (3): 521–34. doi:10.1111/j.1460-9568.2008.06324.x. PMID18702724.