Ced 1401 analogue to digital converter

Subjects were required to attend the laboratory on 3 occasions separated by at least 1 week.
To avoid the confounding influence of diurnal variations in cortisol on the induction of cortical plasticity [24] , all experiments were conducted between 11 am and 4 pm, with repeat sessions within each subject always occurring at the same time of day. During each experimental session, subjects sat in a chair with their right arm abducted approximately 45° at the shoulder, and right forearm and hand resting on a cushion placed next to them. Surface electromyography (EMG) was recorded from the first dorsal interosseous (FDI) muscle of the right hand using two Ag-AgCl electrodes placed approximately 2 cm apart in a belly-tendon montage and a strap placed around the wrist to ground the electrodes. EMG signals were amplified (x 1000) and band-pass filtered (20 Hz-1 kHz) using a CED 1902 signal conditioner (Cambridge Electronic Design Co. Ltd, Cambridge, UK), before being digitized at 2 kHz using a CED 1401 analogue-to-digital converter (Cambridge Electronic Design Co.
Ltd, Cambridge, UK) and stored on a computer for later off-line analysis.

Sciatic nerves were obtained from adult male Swiss mice (28-35 g). The extraction surgery was performed essentially as described by Bala et al. (2014) . The mice sciatic nerves were mounted on a recording chamber according to Dal Belo et al. (2005) . Standard extracellular recording techniques were used to record compound nerve action potentials. Pellet-type silver electrodes were dipped into each of the three compartments of the recording chambers, with stimulation occurring between the central and one of the external compartments. Recordings were obtained from the central compartment. A Grass S48 stimulator was used to supply supramaximal electrical impulses (0.4 Hz, 0.04 ms duration) via a model SIU 5A stimulus isolation unit (Grass Instrument Co.). The signals were amplified with a CED1902 transducer (Cambridge Electronic Design, Cambridge, England), digitalized with a CED 1401 analogue-to-digital converter (Cambridge Electronic Design) and analyzed with custom built software (Dempster, 1993) . In each experiment, the amplitude, rise time, latency and threshold of the recorded action potentials were measured. Before adding the test compounds, the sciatic nerve preparations were incubated in physiological solution for 15 min under constant supramaximal stimulation to demonstrate viability of the preparation and consistency of the recordings.