Frequency-dependent entrainment of spontaneous Ca transients in the dendritic tufts of CA1 pyramidal cells in rat hippocampal slice preparations by weak AC electric field
| Autor: | Hiroyoshi Miyakawa, Kenya Innami, Toru Aonishi, Ichiro Kato, Masashi Inoue, Koki Sakuma |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Male Frequency band Hippocampal slice Field strength Low frequency band Neurotransmission Hippocampal formation Hippocampus Synaptic Transmission Membrane Potentials 03 medical and health sciences 0302 clinical medicine Electric field Animals Rats Wistar CA1 Region Hippocampal Neurons Chemistry General Neuroscience Pyramidal Cells Dendrites Temporal Lobe Rats 030104 developmental biology Synapses Biophysics Calcium Entrainment (chronobiology) 030217 neurology & neurosurgery |
| Zdroj: | Brain research bulletin. 153:202-213 |
| Popis: | Neurons in the central nervous systems are exposed to endogenous oscillating electric fields and their activities are likely to be modified by those fields. We had previously investigated the effects of AC electric field by using a newly developed method to monitor local Ca transients in the dendrites of a neuronal population in acute rat hippocampal slices and reported that spontaneously occurring Ca transients in the tufts of the apical dendrites of CA1 pyramidal neurons become entrained to subthreshold AC electric fields. To further our understanding of the impact of AC fields on dendritic activities, in the present study we examined three questions: how does the extent of entrainment depend on the frequency of the applied field, how does the mean phase of the dendritic activities during field application depend on the frequency of the field, and whether the entrainment can be seen in the absence of synaptic transmission. We have found that, the extent of entrainment is significantly greater at a low frequency band (1–4 Hz) compared to a high frequency band (8–16 Hz), 0.688 ± 0.027 at 2 Hz compared to 0.087 ± 0.016 at 16 Hz in case of 7 mV/mm field strength, that the entrainment can be observed when synaptic transmission is pharmacologically blocked, and that the mean phase of the Ca transients during field stimulation at a low frequency band (1–4 Hz) stays constant. These results indicate that the electric fields with physiologically feasible frequencies and intensities can entrain activities of the dendrites in a frequency-dependent manner independent of synaptic transmission. AC electric fields during oscillatory brain activities might play a role in synchronizing neural activities by modulating dendritic activities. |
| Databáze: | OpenAIRE |
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