All training and testing took place in a custom-built behavioral chamber (43 × 43 × 53 cm; MED Associates, St Albans, VT, USA) housed in a sound-attenuating cabinet. The interior walls of the cabinet were covered in metal mesh to provide insulation from external electrical signals. Chambers were illuminated Ribociclib mw by a houselight located
on the ceiling. Masking noise and ventilation were provided by a wall-mounted fan. A ceiling-mounted digital camera enabled digital recording on a computer (api Software), which was later scored by the experimenter. A centrally-located foodcup (approximately 4 cm above the floor) was mounted on the right wall of the chamber. Flanking the foodcup on either side Smad signaling were two retractable levers (Coulbourn Instruments, Whitehall, PA, USA), both 4 cm above the chamber floor. During Pavlovian training, the levers were retracted from the chamber, but remained extended into the chamber during instrumental training and the final transfer session. Auditory cues consisted of either a tone (70 dB, 1500 Hz) or white noise (65 dB) delivered by a speaker 18 cm above the floor. A red light-emitting diode (LED) was located behind the foodcup (not visible to the rats but recorded on a video camera to aid in behavioral scoring). The LED illuminated
at 10 s prior to auditory cue onset and remained illuminated for the duration of the auditory cues. Electrophysiological recordings were taken on the final day of transfer, although the rats were connected to the recording apparatus for two sessions prior to transfer to habituate them to the tether. Details
on electrophysiological recording have been reported previously (Carelli et al., 2000). Briefly, rats were connected to a recording harness that terminated in a headstage (Plexon Inc., Dallas, TX, USA). The harness was connected at the other end to a commutator (MED Associates and Crist Instruments) allowing free movement throughout the chamber during sessions. C1GALT1 Amplified neural signals were then passed to a Multichannel Acquisition Processor (MAP) system (Plexon Inc.) where they were captured by a neural analysis program (Sort Client, Plexon Inc.). A separate computer controlled external stimuli and captured behavioral events (TRANS IV, MED Associates). Neural data were acquired using techniques and apparatus similar to those described elsewhere (Roitman et al., 2005). Briefly, software was employed to sort neural waveforms by principal components analysis (Offline Sorter, Plexon Inc.). Finally, the resulting timestamps for valid waveforms were further analyzed in relation to behavioral markers using NeuroExplorer software (NEX Technologies, Littleton, MA, USA). Pavlovian training. An overview of all behavioral training appears in Table 1.