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. Author manuscript; available in PMC: 2013 Jul 11.
Published in final edited form as: J Vis Exp. 2012 Apr 15;(62):10.3791/3597 3597. doi: 10.3791/3597

Figure 1. The Giant Fiber System.

Figure 1

Diagram of the Giant Fiber System (GFS). The Giant Fibers (GFs, shown in red) synapse electrically (Gap Junctions) as well as chemically (cholinergic) onto a Peripheral Synapsing Interneuron (PSI, shown in green) and the Tergo Trochanteral Muscle neuron (TTMn, shown in yellow)5. The PSI to DLMn (Dorsal Longitudinal Muscle neuron, shown in blue) connection is dependent on Dα7 nAChR subtype6. Finally the neuromuscular junction (NMJ) of the TTMn and the DLMn onto the jump (TTM, shown in purple) and flight muscles (DLM, shown in purple) is glutamatergic.

Note: The GF to PSI connection is both electrical and chemical. However, in shakB mutants (which lack gap junctions), no response can be recorded from the DLM upon stimulation of the GFs in the brain, demonstrating that the chemical component in the absence of electrical connections is not sufficient to evoke an action potential in the PSI5,16-18. Because the GF to PSI connectionis gap junction dependent, this figure shows only the GAP junction at the synapse for simplicity reasons.