Figure 2.

Long-term sensitization training induces parallel effects on behavior of animals and efficacy of sensorimotor synapses. A, Average data on the changes in duration of siphon-withdrawal reflex 24 h after 4 d LTS training. The tail-elicited siphon withdrawal reflex is sensitized only when the ipsilateral side of the tail is tested. When the contralateral side is tested, the reflex is similar to that elicited by stimulation of untrained animals, indicating that long-term memory for sensitization is unilateral. B, Average data on the peak amplitude of monosynaptic EPSPs recorded from the cell body of motor neurons after triggering spikes in presynaptic sensory neurons. In pleural-pedal ganglia of ipsilaterally trained animals, EPSPs had significantly larger amplitude than in synapses from contralaterally trained and untrained animals. Inset, example traces of EPSPs. **p < 0.01.