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Induction of an Isoelectric Brain State to Investigate the Impact of Endogenous Synaptic Activity on Neuronal Excitability In Vivo
Published on: March 31, 2016
Activity-dependent slow hyperpolarization in cat sensorimotor cortex in vitro
H Kitagawa1, Y Nishimura, Y Kumazawa
1National Institute for Physiological Sciences, Okazaki, Japan.
Brain Research
|June 24, 2000
Summary
Synaptic activity influences neuron resting potential. Tetanic stimulation induced slow hyperpolarization and enhanced afterhyperpolarization, dependent on NMDA receptors and calcium influx.
Area of Science:
- Neuroscience
- Cellular Electrophysiology
Background:
- Resting membrane potential is crucial for neuronal function.
- Synaptic mechanisms regulating resting potential are not fully understood.
Purpose of the Study:
- To investigate the synaptic regulation of resting membrane potential in cat sensorimotor cortex pyramidal neurons.
- To elucidate the role of NMDA receptors and calcium channels in this process.
Main Methods:
- Intracellular recording in slice preparation of cat sensorimotor cortex.
- Tetanic stimulation of white matter to induce synaptic activity.
- Application of NMDA receptor antagonist and calcium channel blocker (Ni2+).
Main Results:
- Tetanic stimulation induced subthreshold depolarization followed by slow hyperpolarization.
- Afterhyperpolarization following action potentials was enhanced.
- Slow hyperpolarization and enhanced afterhyperpolarization were blocked by NMDA antagonist and Ni2+, or by strong hyperpolarization (-80 mV).
Conclusions:
- Synaptic mechanisms involving NMDA receptors and calcium influx regulate resting membrane potential.
- These mechanisms contribute to slow hyperpolarization and enhanced afterhyperpolarization in pyramidal neurons.
