To study the effects of 50 Hz magnetic fields in the range of magnetic flux densities relevant to current environmental exposures on action potential, after-hyperpolarization potential and neuronal excitability in neurons of land snails (Helix aspersa).
|Setup||pair of Helmholtz coils with a diameter of 20 cm, spaced 10 cm apart, consisting each of 325 turns of 0.5 mm copper wire; field homogeneity better than 0.1 µT in the exposure area inside the coils|
|Additional info||exposure time: 18 min exposure - 2 min examination without exposure - additional 2 min exposure (= 20 min)|
When the neurons were exposed to magnetic fields at the various magnetic flux densities, marked changes in neuronal excitability, firing rate (decrease, i.e. inhibition of neuronal activity) and after-hyperpolarization potential amplitude (increase) were found. These effects seemed to be related to the intensity, type (single and continuous or repeated and cumulative) and length of exposure (18 or 20 min). The extremely low frequency magnetic field exposures affected the excitability of F1 neuronal cells in a nonmonotonic manner, disrupting their normal characteristic and synchronized firing patterns.