## 2 Results
### Acute Exposure
#### 2.1.7 Fluorescence-Microscopic Observations of GFP Fusion-Proteins  
Transcriptional changes do not necessarily mean changes in translation and protein amount, as many post-translational and post-transcriptional processes, such as mRNA and protein stability or degradation can influence the amount of protein. Therefore we used five _C. elegans_ strains, where neuron-specific proteins were tagged with GFP, to evaluate the impact of the substances to protein synthesis as well as to the neurons: Dopaminergic neurons (BZ555 (_dat-1_:GFP)), glutamatergic neurons (DA1240 (_eat-4_:GFP)), GABAergic neurons (EG1285 (_unc-47_:GFP)), serotonergic neurons (GR1366 (_tph-1_:GFP)) and cholinergic neurons (LX929 (_unc-17_:GFP)). The fluorescence intensity of the whole nematode was measured using Image J software and the corrected total cell fluorescence (CTCF) was calculated. For more details on the strains please refer to Section 4.1 and for detailed information on the tagged genes to Table 2 and Table S6. In order to evaluate the impact of the substances to survival of the neurons, the number of neurons has been counted out. This was possible only for BZ555 and EG1285, as EAT-4 (DA1240) and TPH-1 (GR1366) are not expressed in each of the eight serotonin or glutamate neurons and UNC-17 (LX929) is expressed in over 120 cholinergic neurons. None of the substances led to death of neurons either after 24 h or 72 h of incubation in one of the strains. As shown in Figure 2C the amount of UNC-47 was decreased after exposure to 0.1 TBBP-A, but increased after 24 h incubation with the mixture of 50 \(\upmu\)M TBBP-A and 50 \(\upmu\)M DBAA. However, the quantity of protein after incubation with the mixture containing 0.1 \(\upmu\)M TBBP-A increased in relation to its single components (Table 5), while the other mixture increased it relative to 50 \(\upmu\)M DBAA. High concentrated TBBP-A and both mixtures increased the CTCF in BZ555 after 24 h (Figure 2A). TBBP-A \begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**Gene**} & **0.1 \(\upmu\)M TBBP-A + 50 \(\upmu\)M DBAA Relative to** & **50 \(\upmu\)M TBBP-A + 50 \(\upmu\)M DBAA Relative to** \\ \cline{2-5}  & **0.1 \(\upmu\)M TBBP-A** & **50 \(\upmu\)M DBAA** & **50 \(\upmu\)M TBBP-A** & **50 \(\upmu\)M DBAA** \\ \hline _ace-1_ & n.s. & n.s. & n.s. & n.s. \\ _casy-1_ & * & * & n.s. & n.s. \\ _che-12_ & * & * & n.s. & n.s. \\ _dat-1_ & * & * & n.s. & n.s. \\ _dop-1_ & n.s. & n.s. & n.s. & n.s. \\ _dop-3_ & * & * & n.s. & n.s. \\ _eat-4_ & n.s. & n.s. & n.s. & n.s. \\ _gbb-1_ & * & * & n.s. & n.s. \\ _grd-12_ & n.s. & n.s. & n.s. & n.s. \\ _hda-4_ & n.s. & n.s. & n.s. & n.s. \\ _hen-1_ & n.s. & * & * & n.s. \\ _mec-10_ & ** & ** & * & n.s. \\ _srab-6_ & * & * & n.s. & n.s. \\ _tph-1_ & * & * & n.s. & n.s. \\ _ttx-3_ & n.s. & n.s. & n.s. & n.s. \\ _unc-17_ & n.s. & * & n.s. & n.s. \\ _unc-47_ & n.s. & n.s. & n.s. & n.s. \\ \hline \end{tabular}
\end{table} 
Table 4: Significances (_p_) for the relative fold changes of gene transcription of the mixtures in relation to the single compounds. (0.1 uM) and 50 uM DBAA in a mixture also increased the CTCF in relation to 0.1 uM TBBP-A. After 24 h the fluorescence of strain DA1240 was decreased by 50 uM DBAA. The mixture of the high organobromine concentrations increased the CTCF in relation to the control and to 50 uM DBAA (Figure 2B). However, after 72 h the amount of EAT-4 decreased in all exposures containing 0.1 uM TBBP-A. After 24 h, all substances except 50 uM DBAA increased the amount of UNC-17 in strain LX929 (Figure 2E). Both mixtures also increased the fluorescence in relation to at least one of their individual components. An increased expression was still detectable after 72 h of incubation with 0.1 uM TBBP-A and both mixtures. As seen in Figure 2D, expression of THP-1, marked in strain GR1366, was increased by the mixture of 0.1 uM TBBP-A and DBAA in relation to the control and to both compounds after 24 and 72 h. Table S7 displays the mean values, standard error of the mean and significances.