Plateau potentials

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. PICs are set up by the influence of descending monoaminergic reticulospinal 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.

Olfactory bulb

Periglomerular cells, inhibitory interneurons that surround and innervate olfactory glomeruli, have also been shown to exhibit plateau potentials.

Cortex and hippocampus

Plateau potentials are also seen in the cortical, and hippocampal pyramidal 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

  1. 1 2 Svirskis, 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. PMID 11152739.
  2. ↑ Masurkar, AV; Chen, WR (29 September 2011). "Potassium currents of olfactory bulb juxtaglomerular cells: characterization, simulation, and implications for plateau potential firing". Neuroscience. 192: 247–62. doi:10.1016/j.neuroscience.2011.06.012. PMC 3170655. PMID 21704678.
  3. ↑ Zhou, Z; Xiong, W; Masurkar, AV; Chen, WR; Shepherd, GM (November 2006). "Dendritic calcium plateau potentials modulate input-output properties of juxtaglomerular cells in the rat olfactory bulb". Journal of Neurophysiology. 96 (5): 2354–63. doi:10.1152/jn.00003.2006. PMID 16855116. S2CID 11512553.
  4. ↑ Major, G; Polsky, A; Denk, W; Schiller, J; Tank, DW (May 2008). "Spatiotemporally graded NMDA spike/plateau potentials in basal dendrites of neocortical pyramidal neurons". Journal of Neurophysiology. 99 (5): 2584–601. doi:10.1152/jn.00011.2008. hdl:11858/00-001M-0000-002C-07A3-4. PMID 18337370.
  5. ↑ Milojkovic, BA; Radojicic, MS; Antic, SD (13 April 2005). "A strict correlation between dendritic and somatic plateau depolarizations in the rat prefrontal cortex pyramidal neurons". The Journal of Neuroscience. 25 (15): 3940–51. doi:10.1523/JNEUROSCI.5314-04.2005. PMC 5643048. PMID 15829646.
  6. ↑ 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. PMID 18702724.