Neuromuscular junctions and L-glutamate-sensitive sites in the fleshfly, Sarcophaga bullata.

Sites have been located on retractor unguis and trochantal depressor muscle fibres of Sarcophaga which respond to iontophoretic application of l-glutamate. No such sites could be found on flight muscle fibres. Ultrastructural examination of the three muscles reveals differences between the muscles in the positions of the neuromuscular junctions. A correlation can be made between the sites of the neuromuscular junctions and the iontophoretically sensitive sites. The possibility of l-glutamate fulfilling a transmitter rôle in these muscles is discussed.