| The
Murphey lab uses
molecular genetic and physiological methods to study synapse
formation in Drosophila. The image shows most of the CNS of
the adult Drosophila. A single giant interneuron of the fly
has been labeled by targeted expression of lacZ, which was visualized
by immunocytochemistry. The soma is in the brain and the axon
terminates in the thorax where it innervates the jump motor
neuron and controls visual escape behavior. The image on the
right shows the same neuron where the retrograde cytoplasmic
motor has been disrupted by targeted expression of a poison
subunit. This disrupts synaptogenesis as shown by the swollen
terminals of the giant axon. The overlaid tracing, which is
a recording from the “jump” muscle in control and
experimental animals, shows that the experimental muscle no
longer follows the stimulus reliably indicating that the synapse
between the giant interneuron and the motor neuron has been
weakened. The results demonstrate that retrograde signaling
within the giant interneuron is critical to the final stages
of synapse assembly. |
