To investigate the potential therapeutic effect of a 50 Hz magnetic field on neurogenesis and memory in a mouse model for hippocampal injury.
The mouse model for hippocampal injury was induced by administration of trimethyltin chloride (TMT), a neurotoxin.
Four groups of mice were examined (14 animals per group, respectively): 1) control group, 2) intraperitoneal injection of saline solution, 3) intraperitoneal injection of TMT (2.5 mg/kg) and 4) intraperitoneal injection of TMT (2.5 mg/kg) + magnetic field exposure.
On day 0, the mice of the groups 2, 3, and 4 received the intraperitoneal injection with saline solution or TMT. On day 3, magnetic field exposure started for group 4 and mice from all groups received an intraperitoneal injection (50 mg/kg) of bromodeoxyuridine (repeated on day 4 to day 9). On day 9, three mice per group were killed for Western blot analysis and four mice per group for immunohistochemistry analysis (neurogenesis). The remaining mice were tested (or training started?) in the Morris water maze on day 32 and killed for immunohistochemical analysis (neuronal maturation) on day 37.
| Exposure | Parameters |
|---|---|
| Exposure 1: 50 Hz |
|
| Frequency | 50 Hz |
|---|---|
| Type |
| Exposure source | |
|---|---|
| Chamber | animals were exposed in a plastic cage inside the center of a cylinder surrounded by solenoids |
| Setup | two solenoids were connected to an AC power generator; each solenoid was made of a 380 turn-coil (diameter 19 cm and length 17.5 cm) and a long magnetic wire twisted around a Plexiglass cylinder; temperature was measured and controlled with an external temperature sensor to minimize temperature changes |
| Sham exposure | A sham exposure was conducted. |
| Additional info | a similar setup was placed in an EMF-protected container for the control group |
| Measurand | Value | Type | Method | Mass | Remarks |
|---|---|---|---|---|---|
| magnetic flux density | 1 mT | - | measured | - | - |
Mice which received the neurotoxin TMT (group 3) had showed significantly impaired learning and memory abilities in the Morris water maze, when compared to the control group (group 1) and to the group that received an injection of saline solution (group 2). However, mice which received TMT and were exposed to the magnetic field (group 4) did not show these impairments: No significant differences compared to the control group were found. Similar, the neurogenesis and the neuronal maturation were affected in mice treated with TMT as shown in a significant decrease of the bromodeoxyuridine incorporation and a significantly lower expression level of NeuN in the dentate gyrus compared to the control group and to the group that received saline solution. Again, this effect was reversed by magnetic field exposure. The Western blot analysis showed that in magnetic field exposed and TMT treated mice (group 4), the protein expression of NeuroD2 was significantly increased compared to the TMT-treated group (group 3).
The authors conclude that exposure to 50 Hz magnetic fields could improve learning and memory impairment in a mouse model for hippocampal injury and that this effect could be attributed to the induction of neurogenesis.
This website uses cookies to provide you the best browsing experience. By continuing to use this website you accept our use of cookies.
