The effect of a static magnetic field on the morphometric characteristics of neurosecretory neurons and corpora allata in the pupae of yellow mealworm Tenebrio molitor (Tenebrionidae)

Abstract

Purpose: The morphometric characteristics of A1 and A2 protocerebral neurosecretory neurons (cell and nuclei size, number of nucleoli in the nuclei); corpora allata size, nuclei size, cell number, were investigated in the pupae of yellow mealworm, Tenebrio molitor (L.), exposed to a strong static magnetic field of 320 mT maximum induction (10,000 times higher than the Earth's). Materials and methods: The experimental groups of Tenebrio molitor pupae were: A control group exposed only to natural magnetic field and sacrificed at the eighth day of pupal development (C); and pupae kept in a strong static magnetic field for eight days and then sacrificed (MF). Serial brain cross-sections were stained using the Alcian Blue Floxin technique. All the parameters were analyzed and measurements were performed using an image processing and analysis system (Leica, Cambridge, UK) linked to a Leica DMLB light microscope (program is QWin - Leica's Quantimet Windows-based image analysis tool kit). Results: The values of morphometric parameters of neurosecretory neurons and corpora allata were significantly increased after exposure of the pupae to the strong magnetic field. Conclusions: The strong magnetic field influence characteristics of protocerebral neurosecretory neurons and corpora allata in the late Tenebrio molitor pupae.