Description

In C. elegans, the reuptake of serotonin (5-HT) is facilitated by mod-5, which encodes a 5-HT transporter that is orthologous to a human 5-HT transporter (SLC6A4).  mod-5 has been shown to effect both feeding and locomotion in C. elegans (Ranganathan et al., 2001; Jafarau et al. 2011).  We obtained and analyzed EPG data using a microfluidic device (NemaMetrix) for mod-5 null mutant strains, mod-5(n3314) (A, Exp 1 n=15; Exp 2 n=32) and mod-5(n822), (B, Exp 1 n=17; Exp 2 n=27) and N2 control worms (A, n=16 and 31; B, n=18 and 27 for Exp 1 and 2, respectively) in M9 saline buffer (2-minute recording duration). Mutations to the C. elegans serotonin reuptake transporter, mod-5, lead to an accumulation of serotonin at the synaptic cleft, which results in a significant increase in baseline pharyngeal pumping frequency in three out of four experiments (A, N2=0.10 ± 0.04 and 0.09 ± 0.03 Hz ; mod-5(n3314)=1.41 ± 0.44 and 2.26 ± 0.13 Hz; B, N2=0.98± 0.42 and 0.44 ± 0.08; mod-5(n822)=1.64 ± 0.33 and 3.76 ± 0.19 Hz; **p<0.005, ***p<0.0001, 2-tailed students t-test).