A1x32 poly3 10 mm 50 177

In four animals from the DM12 group, unit recording was performed under isoflurane anesthesia. Broadband (1–7500 Hz) electrophysiology signals were acquired at a sample rate of 30 kHz from the DG of the rat, using a 32-channel silicon probe (A1x32-Poly3-10 mm-50-177; Neuronexus), with the Open Ephys acquisition system (www.open-ephys.org) and an Intan amplifier/filter and digitizer boards (Intan Technologies). The Intan boards digitize the signals in a ± 6.4 mV, 16-bit integer range. The probe was lowered at in the right hippocampus 4.2 mm posterior and 3 mm lateral to λ. Activity was found around 3-mm depth and was estimated as putative DG activity. Around 30 min of baseline activity was recorded, followed by subcutaneous injection of vehicle and clozapine (0.1 mg/kg) and another ∼40 min of recording.

Extracellular recordings were implemented using 32-channel 10-mm single shank electrodes, where electrode sites were arranged in three columns, spaced 50 microns apart from each other (A1x32-Poly3-10mm-50-177, NeuroNexus, Ann Arbor, MI, USA). Electrodes were inserted into the rodent skull using a small animal stereotaxic frame with 10-micron precision manipulators (Model 963, David Kopf Instruments, Tujunga, CA, USA). Electrodes were inserted at a 40-degree angle in the sagittal plane.
Rodents were sedated using either ketamine/xylazine cocktail for results presented in Figs. 3b–g and 4 or isoflurane for results in Figs. 3a, 5, 6, and 7. All animals were skin prepared with hair removal gel. Rodent heart rate, respiration rates and rectal temperatures were monitored throughout recordings. Cranial windows, 1–2 mm in diameter, were opened in the skull using a high-speed micro drill (Model 1474, David Kopf Instruments, Tujunga, CA, USA) under stereotaxic surgery assisted with microscope system (V-series otology microscope, JEDMED, St. Louis, MO, USA). Skull suture lines were used to identify brain structure locations. Recordings were obtained using the NeuroNexus Smartbox recording system (20 kHz sampling frequency, NeuroNexus, Ann Arbor, MI, USA) and the TDT Neurophysiology Workstation (24 kHz sampling frequency, Tucker-Davis Technologies, Alachua, FL, USA).