MusFIG 16: Innervation of head muscles for foraging.
The long, synapse-free processes of SAA and SMB may become activated by the head curving when ventral muscles contract (only SMBD, which makes chemical synapses onto dorsal head muscles, and SAAD are shown). These may in turn activate the GABAergic and inhibitory RME neurons, which would relax the contracted muscles on the ventral side. Mutant animals that lack GABAergic transmission have exaggerated, ìloopyî head movements. RMEs also receive input from mechanosensory IL1, IL2, OLQ, and OLL neurons. (Arrows) Chemical synapses; (T bars) inhibitory, GABAergic transmission; (double bars) gap junctions. (Based on White et al., 1986; Jorgensen, 2005.)
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