Fig. 1
From: Genetic background mutations drive neural circuit hyperconnectivity in a fragile X syndrome model
Presynaptic projections from the giant fiber interneuron terminal bend. a Co-injection of TRITC-dextran (10 kDa; magenta) and neurobiotin (287 Da; yellow) into a w1118 giant fiber interneuron (GFI) axon labels the neuron and all the gap junction dye-coupled GF circuit neurons. Visible are peripherally synapsing interneuron (PSI), tergotrochanteral motor neuron (TTMn) cell body, and giant fiber coupled (GFC) 1–4 neurons, which were just recently characterized (Kennedy and Broadie 2018). The GFI inframedial bridge (IB, arrowhead) and GFI axonal bends (arrow) located in the second thoracic ganglion segment are the two presynaptic sites. b Enlarged image of one GFI axonal bend (see box in a) showing the newly identified presynaptic projections (arrows). Scale bars, 25 μm (a) and 5 μm (b)