The effects of acute exposure to magnetic fields on morphometric characteristics of bombyxin-producing neurosecretory neurons in gypsy moth caterpillars

Abstract

Purpose: To examine the effects of acute exposure to strong static magnetic fields and extremely low frequency magnetic fields, on neurosecretory neurons which synthesise insulin-like neurohormone.

Materials and methods: Immunocytochemical detection of bombyxin-like material in the protocerebral neurosecretory neurons of Lymantria dispar caterpillars was performed using a monoclonal antibody directed against a synthetic dekapeptide corresponding to the N-terminus of the bombyxin A-chain. Caterpillars were exposed to strong static magnetic fileds (235 mT) and extremely low frequency magnetic fields (2 mT) for three days after moulting into the 4th instar.

Results: We report the presence of immunoreactive molecules in A2 type of medial neurosecretory neurons (nsn) in caterpillars' brain of L. dispar. The three-day exposure of caterpillars to stresogenic external magnetic fields changed the size of A2 type nsn, their nuclei and the intensity of protein band in the region of bombyxin molecular mass (4–6 kD) after exposure to extremely low frequency magnetic fields in comparison to control group and group treated by strong static magnetic fields.

Conclusion: These are the first data on the influence of external magnetic fields on the polyphagous phytophagous forest pest L. dispar L. (Lepidoptera: Lymantridae) indicating an intensive synthesis of insulin-like neurosecretory material.

Keywords:

• bombyxin
• Lymantria dispar
• neurosecretory neurons
• magnetic fields

Acknowledgements

We thank Prof Dr Akira Mizoguchi of the Department of Biology, Nagoya University, Nagoya, Japan, for the kind gift of the mouse bombyxin monoclonal antibody. This study was supported by the Serbian Ministry of Science and Technological Development (grant No.173027).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.