ApHTT in presynaptic sensory neurons is required for the initiation of LTF.

<p>A: RNA <i>in situ</i> hybridization at 3 hours after oligonucleotides injection. Injection of ApHTT anti-sense oligonucleotides into the presynaptic sensory neuron lead to a decrease in ApHTT mRNA level. Confocal projection images are shown. The scale bar represents 20 µm. The summary bar graph is on the right (N = 8). B: Representative traces of EPSPs that were recorded from motor neurons in response to extracellular stimulation of sensory neurons before and 5 minutes after exposure to 1×5-HT (10 µM, 5 minutes) for STF or before and 24 hours after exposure to 5×5-HT (10 µM, 5 minutes) for LTF. C: Injection of ApHTT anti-sense oligonucleotides in the presynaptic sensory neuron has no effect on STF. D: Injection of ApHTT anti-sense oligonucleotides blocks LTF. Changes in EPSP amplitudes are shown in bar graphs. Error bars are SEM. SN: sensory neuron, MN: Motor neuron.