## 3 Discussion  
### Increased Pumping Frequency Leads to Increased Growth  
An increased pumping frequency leads to a faster intake of food overall. In addition, the distribution of ingested food is supported [20], thus nutrients could be absorbed easier [21]. The organism could therefore rely on better energy support which could be distributed between growth and maintenance [22]. Figure 5 gives an overview of possible associations between pumping and growth and lifespan, respectively. Green connections thereby represent influences that have been observed under laboratory conditions, whereas red connections represent influences that may increase the toxicity under natural conditions (such as decreased detection of food and stressors by decreased chemical perception) but should not do so under artificial conditions and feeding _ad libitum_. In the present study, an increased pumping frequency was found after incubation with 0.1 \(\upmu\)M TBBP-A, 50 \(\upmu\)M DBAA and the mixture of both. This mainly correlates with the increase in growth previously determined by [PERSON] _et al._[7]. Because of the eutelie in _C. elegans_[23], growth cannot be achieved by an increased cell-number. Thus the increase in body length was caused by increased cell-size [24] which is caused, among other things, by increased storage of transcription- and translation-products [25, 26]. This hypothesis is supported by the fact that 50 \(\upmu\)M DBAA increases the biosynthesis [7]. The increase of body length therefore is most likely caused by the intensified uptake of food. Figure 4: Corrected total cell fluorescence (CTCF) of _C. elegans_ strain LX929 after exposure to the different substances during different developmental stages. Bars represent means \(\pm\) SEM (One Way ANOVA (Holm-Sidak-method)). **Dark grey bars**: Control, **white bars**: 0.1 \(\upmu\)M TBBP-A, **black bars**: 50 \(\upmu\)M TBBP-A, **light grey bars**: 50 \(\upmu\)M DBAA, **spotted bars**: 0.1 \(\upmu\)M TBBP-A + 50 \(\upmu\)M DBAA, **stripped bars**: 50 \(\upmu\)M TBBP-A + 50 \(\upmu\)M DBAA. Significances are shown as \(p<0.05\) (*) and \(p<0.001\) (**). In the present study the increased pumping frequency mainly correlates with the prior detected delayed senescence, an effect that has been reported before by [PERSON] _et al._[27] and [PERSON] _et al._[28]. Because of the stimulating effect of 50 \(\upmu\)M DBAA on biosynthesis and metabolism [7], an energy-saving mode, as required for calorie restriction [29, 30], is probably not the reason for the life-extension. According to the life-history theory [31], the increased amount of energy by enhanced pumping could not only be used for growth but also for maintenance. Thus, damage occurring for example on the DNA can be repaired much more efficiently, which may lead to a delayed senescence. The inverse conclusion is also possible: the increased pumping frequency does not cause the life-extension but is caused by it. Pumping frequency decreases with increasing age and therefore is a  
Figure 5: Linking between the analyzed physiological and neuronal behaviors. Identification beneath the neurophysiological parameters (**3.x**) refers to the subchapter, where this connection is discussed. **Dotted lines**: possible connection, **solid line**: proved connection, \(\blacktriangleright\) : reverse effect, \(\blacktriangleright\) : inverse effect, **red**: influence may appear under natural conditions, **green**: influence under laboratory conditions. measure of individual fitness [32]. Substances delaying senescence also cause individuals to be \"younger\" after the same time has passed. Thus these nematodes would have higher pumping frequencies than untreated worms. Pumping frequency is modulated by the MC (L&R) and M3 (L&R) neurons [33, 34], which use acetylcholine and glutamate, respectively [35] (Figure 6). Transcription of _eat-4_, a glutamate transporter, and _unc-17_, an acetylcholine transporter, were significantly increased after incubation with the mixture of 50 uM of both organobromines.