Larvae of the hawkmoth, @entity4079 , exhibit a defensive proleg withdrawal reflex in which deflection of mechanosensory hairs on the proleg tip (the planta) evokes retraction of the proleg. A previous behavioral study showed that this reflex habituates in response to repeated planta hair deflection and exhibits several other defining features of @entity734 . In a semi-intact preparation consisting of a proleg and its associated segmental @entity4494 , repeated deflection of a planta hair or electrical stimulation of its sensory neuron causes a neural correlate of @entity734 , manifested as a decrease in the number of action potentials evoked in the proleg motor nerve. Monosynaptic connections from planta hair sensory neurons to the principal planta retractor motoneuron exhibit several forms of activity-dependent plasticity. In the present study we recorded intracellularly from this motoneuron during repetitive electrical stimulation of a planta hair sensory neuron. The number of action potentials evoked in the motoneuron decreased significantly, representing a neural correlate of @entity734 . The motoneuron's resting membrane potential, input resistance. and spike threshold measured before and after repetitive stimulation did not differ between the stimulated group and a control group. Furthermore, the amplitude of the monosynaptic excitatory postsynaptic potential, as well as the magnitude of paired-pulse facilitation, evoked in the motoneuron by the sensory neuron did not change after repetitive stimulation. These results suggest that @entity308 at the sensorimotor synapse does not contribute to reflex @entity734 . Rather, other mechanisms in the @entity4494 of the stimulated segment, such as changes in polysynaptic reflex pathways, appear to be responsible.

Habituation of the proleg withdrawal reflex in @entity4079 does not involve changes in motoneuron properties or XXXX at the sensorimotor synapse.

@entity4079 :: ('7130', 'Species') :: ['Manduca sexta'] @entity308 :: ('MESH:D003866', 'Disease') :: ['depression'] @entity734 :: ('MESH:D019966', 'Disease') :: ['habituation'] @entity4494 :: ('MESH:D045888', 'Disease') :: ['ganglion']
@entity308 :: (MESH:D003866,Disease) :: ['depression']
