The final radius was chosen randomly from 1, 1/2, 1/4, 1/8, and 1/16 of the full size. We identified the smallest final size at which the cocontraction was initiated and varied it slightly around that value to get a better estimate. Nerve cord, flexor, and extensor muscle activities selleck kinase inhibitor were recorded and transmitted wirelessly as described above. The extracellular activity of the nerve cords ipsi- and contralateral to the stimulated eye was recorded simultaneously in nine fixed locusts at l/|v| = 10–60 (in steps of 10), 80, 100, and 120 ms. Looming-evoked escape behaviors were studied in six locusts, before and after cutting one of

their nerve cords. Looming stimuli were presented to the eyes ipsi- and contralateral to the sectioned nerve cord at l/|v| = 40, 80, and 120 ms. Laser ablation allows the selective inactivation of a single neuron after filling it with a phototoxic dye (Miller and Selverston, 1979 and Jacobs and Miller, 1985). Animals were mounted ventral side up on a holder, and a hook electrode was implanted around one nerve cord between the pro- and mesothoracic ganglia; the other nerve cord was sectioned, and the cuticle was sealed back in place. The quality of the extracellular nerve cord recording

was then tested; laser ablation was only attempted when it was high (e.g., Figure S6A). Next, the locust head this website was tilted backward and a vertical incision was made in the neck skin, exposing the nerve cords running between the subesophageal and prothoracic ganglia. A small area of the intact nerve cord was desheathed with fine forceps. To achieve mechanical stability during intracellular recordings, we raised the nerve cord and secured it in place

with a pair of polyimide tubes placed under and at the boundary of the desheathed area (039-1; MicroLumen, Tampa, FL). Glass electrodes were pulled on a Brown-Flaming micropipette puller (P-97, Sutter Instrument Company, Novato, CA) with thin-wall capillaries with an outer diameter of 1.2 mm (WPI, Sarasota, FL). The tips of the electrodes were filled Levetiracetam with 4 μl of 10 mM 6-carboxy-fluorescein (Sigma, St. Louis, MO) and the shafts with 6 μl of a 2 M KAc, 0.5 m KCl solution. The electrode resistances varied between 45 and 50 MΩ. The DCMD axon is located dorsomedially in the nerve cord and was identified based on the one-to-one correspondence with the largest spikes in the extracellular recording. It was filled by electrophoresis for 12 min with currents between −1 and −12 nA. The filling was monitored visually by means of a fluorescence module attached to a stereomicroscope. After filling, the intracellular electrode was removed and the saline level was lowered to minimize the loss of laser power because of light scattering. Laser light was directed onto the axon while the activity of the DCMD was monitored on the extracellular electrode to confirm its eventual laser ablation, typically after 2–5 min.