Fish. doi:10.1371/journal.pone.0051456.gboth genotypes. As shown in Figure 5B, pairs of presynaptic fiber stimulation pulses delivered at inter-pulse intervals of 20, 50, 100, 150 and 200 milliseconds evoked nearly identical amounts of PPF in slices from wild-type and fmr1 KO zebrafish. We suggest that basal glutamatergic transmission and presynaptic function at the Dl-Dm synapse remain normal in fmr1 KO zebrafishSynaptic plasticity in fmr1KO zebrafishIn zebrafish, FMRP is highly expressed in the telencephalon [33], an important brain region involved in synaptic plasticity and learning and memory processes. This fact raises an intriguing possibility that FMRP is involved in synaptic plasticity. We nextcompartment (Fig. 2A, p,0.01) and had greater numbers of midline crossings compared to wild-type fish (Fig. 2B, p,0.01), indicating lower anxiety and increased locomotion in KO fishes.Impaired inhibitory avoidance learning in fmr1 KO zebrafishThe inhibitory avoidance test has been extensively used for assessing memories of aversive experiences. In this study, fmr1 KO and wild-type fish were trained in the inhibitory avoidance learning task, and latency to enter the deep compartment was assessed 24 h after training. As illustrated in Figure 3 the difference between the latencies in the training and test sessions for wild-type was statistically significant (Fig. 3, n = 10, p,0.05). In contrast, no significant difference was observed in the fmr1 KO fishes. Additionally, the retention test was GSK343 significantly different (p,0.05) between wild-type and fmr1 KO fish.Hyperactivity in fmr1 KO zebrafishHyperactivity is the most common symptom of FXS patients and fmr1 KO mice. To determine whether genotypic differences in locomotor activity were present between genotypes, the total distances swam and mean speeds of fmr1 KO and wild-type fish were calculated in an open field apparatus for 1531364 5 min. As shown in Figure 4, the total distances moved and the mean speeds of fmr1 KO fish were higher than those of wild-type fish (p,0.001 for both outcomes).Basal synaptic transmission and PPF in fmr1 KO zebrafishBasal synaptic transmission at the Dl-Dm synapse was measured by field potential responses to increasing stimulation intensities. As shown in Figure 5A, the amplitude of the population spikes obtained from wild-type and fmr1 KO slices were compared, and no significant difference between genotypes was noted. Additionally, paired pulse facilitation (FFP) was measured in slices fromFigure 4. Locomotor activity of fmr1 KO and wild-type fish. Bar graphs of the total distance moved (in cm) and mean speeds (in m/sec) of fmr1 KO and wild-type fish. **p,0.001 compared with wild-type fish. doi:10.1371/journal.pone.0051456.gBehavior Synapse Features in Fragile X SyndromeFigure 5. Basal synaptic function is not different between fmr1 KO and wild-type fish. (A) Summary of the input-output curves that were created by comparing PS amplitude and stimulus intensity (40?30 mA)(n = 6). (B) Paired-pulse facilitation (FFP) was measured by applying paired stimuli and quantifying the facilitation of the second potential relative to the first as a function of the inter-pulse interval (,200 ms)(n = 7). doi:10.1371/journal.pone.0051456.MedChemExpress GSK2816126A gexamined whether the loss of FMRP function in zebrafish was related to modulation of synaptic plasticity; to do this, long-term potentiation (LTP) and long-term depression (LTD) were characterized. As shown in Figure 6, LTP was induced by a standar.Fish. doi:10.1371/journal.pone.0051456.gboth genotypes. As shown in Figure 5B, pairs of presynaptic fiber stimulation pulses delivered at inter-pulse intervals of 20, 50, 100, 150 and 200 milliseconds evoked nearly identical amounts of PPF in slices from wild-type and fmr1 KO zebrafish. We suggest that basal glutamatergic transmission and presynaptic function at the Dl-Dm synapse remain normal in fmr1 KO zebrafishSynaptic plasticity in fmr1KO zebrafishIn zebrafish, FMRP is highly expressed in the telencephalon [33], an important brain region involved in synaptic plasticity and learning and memory processes. This fact raises an intriguing possibility that FMRP is involved in synaptic plasticity. We nextcompartment (Fig. 2A, p,0.01) and had greater numbers of midline crossings compared to wild-type fish (Fig. 2B, p,0.01), indicating lower anxiety and increased locomotion in KO fishes.Impaired inhibitory avoidance learning in fmr1 KO zebrafishThe inhibitory avoidance test has been extensively used for assessing memories of aversive experiences. In this study, fmr1 KO and wild-type fish were trained in the inhibitory avoidance learning task, and latency to enter the deep compartment was assessed 24 h after training. As illustrated in Figure 3 the difference between the latencies in the training and test sessions for wild-type was statistically significant (Fig. 3, n = 10, p,0.05). In contrast, no significant difference was observed in the fmr1 KO fishes. Additionally, the retention test was significantly different (p,0.05) between wild-type and fmr1 KO fish.Hyperactivity in fmr1 KO zebrafishHyperactivity is the most common symptom of FXS patients and fmr1 KO mice. To determine whether genotypic differences in locomotor activity were present between genotypes, the total distances swam and mean speeds of fmr1 KO and wild-type fish were calculated in an open field apparatus for 1531364 5 min. As shown in Figure 4, the total distances moved and the mean speeds of fmr1 KO fish were higher than those of wild-type fish (p,0.001 for both outcomes).Basal synaptic transmission and PPF in fmr1 KO zebrafishBasal synaptic transmission at the Dl-Dm synapse was measured by field potential responses to increasing stimulation intensities. As shown in Figure 5A, the amplitude of the population spikes obtained from wild-type and fmr1 KO slices were compared, and no significant difference between genotypes was noted. Additionally, paired pulse facilitation (FFP) was measured in slices fromFigure 4. Locomotor activity of fmr1 KO and wild-type fish. Bar graphs of the total distance moved (in cm) and mean speeds (in m/sec) of fmr1 KO and wild-type fish. **p,0.001 compared with wild-type fish. doi:10.1371/journal.pone.0051456.gBehavior Synapse Features in Fragile X SyndromeFigure 5. Basal synaptic function is not different between fmr1 KO and wild-type fish. (A) Summary of the input-output curves that were created by comparing PS amplitude and stimulus intensity (40?30 mA)(n = 6). (B) Paired-pulse facilitation (FFP) was measured by applying paired stimuli and quantifying the facilitation of the second potential relative to the first as a function of the inter-pulse interval (,200 ms)(n = 7). doi:10.1371/journal.pone.0051456.gexamined whether the loss of FMRP function in zebrafish was related to modulation of synaptic plasticity; to do this, long-term potentiation (LTP) and long-term depression (LTD) were characterized. As shown in Figure 6, LTP was induced by a standar.
