Figure 3. Life Span of Sensory Neuron Varicosities in Untreated Sensory-Motor Neuron Co-Cultures.
(A) Percentage of varicosities that are stable, new and eliminated (number of varicosities added or eliminated at either 24 hr, 72 hr or 120 hr as a percentage of the number of pre-existing varicosities at time 0) over a period of 6 days in untreated cultures. (B) Repeated imaging of the axonal arbor of a sensory neuron in contact with the motor neuron under untreated conditions (no 5-HT) reveals that the majority of presynaptic varicosities are stable (green arrowheads) for at least 120 hr. The yellow arrowhead indicates a sensory neuron varicosity that is going to be eliminated, while the red arrowhead indicates a newly formed varicosity that appears at 72 hr and is still present at 120 hr.