COMBINED LONG-TERM NERVOUS SYSTEM EFFECTS OF FUSARIUM MYCOTOXINS EXAMINED ON RAT BRAIN SLICES
Mycotoxins are toxic secondary metabolites produced by microscopic fungi; the most common Fusarium toxins in Europe – fumonisin B1 (FB1), deoxynivalenol (DON) and zearalenone (ZEA) – may contaminate the food chain. FB1 is known for inhibiting de novo sphingolipid biosynthesis, DON decreases protein synthesis, while ZEA can interact with estrogen receptors. There is increasing evidence that these substances may affect nervous system functions as well. Moreover, crops often contain these toxins in combinations and interactions between them are also possible. The aim of the present study was to examine the combined, long-term neuronal effects of the three mycotoxins with microelectrophysiological methods. Wistar rats of both sexes were gavaged for 28 days with low-dose mycotoxin combinations. Then, neuronal network functions in neocortex and hippocampus were analyzed on ex vivo brain slices, with conventional glass electrode and microelectrode array technique. Single cell characteristics were studied with whole-cell patch clamp. In previous experiments on the effects of individual toxins, FB1 and DON had an overall excitatory effect, while ZEA mostly altered the pattern of induced epileptiform activity. However, given in pairwise combinations, FB1-DON, FB1-ZEA and DON-ZEA all inhibited neuronal network functions to a different extent. The intensity of effects strongly depended on the sex of the rats, also. The analysis of patch clamp results is still in progress. To summarize, the three Fusarium toxins exert markedly different effects on the nervous system when applied individually as compared to combination effects. Supported by National Research, Development and Innovation Fund, grant numbers: NVKP 16-1-2016-0016 and VEKOP-2.3.3-15-2017-00019.