Experimental details:

Whole cell patch clamp recordings were made from layer 3 frontal cortical pyramidal cells in frontal cortical slices (300 µm thick) of 8 month old wild-type and Tg4510 mice.

·  Ringer’s solution, concentrations (in mM): 25 NaHCO3, 124 NaCl, 1 KCl, 2 KH2PO4, 10 Glucose, 2.5 CaCl2, 1.3 MgCl2, pH 7.4; Sigma-Aldrich, St. Louis, MO).

·  Patch pipette internal solution: Potassium methanesulfonate internal solution, concentrations (in mM): 122 KCH3SO3, 2 MgCl2, 5 EGTA, 10 NaHEPES) containing 1% biocytin (pH 7.4; Sigma-Aldrich, St. Louis, MO). In Ringers solution, pipettes had a resistance of ~5 MΩ.

·  “PatchMaster” acquisition software (HEKA Elektronik, Lambrecht, Germany) was used for data acquisition with EPC-9 and EPC-10 amplifiers (HEKA Elektronik, Lambrecht, Germany). Signals were low-pass filtered at 10 kHz. Cells were maintained at resting membrane potential during current-clamp recordings.


Key to data:

May 17 IR1F

A pyramidal cell from an 8 month old Tg4510 mouse. The parent folder contains 17 sub-folders with data from different electrophysiological series as follows:

Series 1-1: Voltage Clamp, Vhold -70 mV, step to -90 mV to monitor access

Series 1-2: Voltage Clamp, IV relation, -120 to +20 mV steps

Series 1-3: Voltage Clamp, protocol to evoke slow afterhyperpolarization current

Series 1-4: Voltage Clamp, Vhold -70, step to -90 to monitor access

Series 1-5: Current Clamp, Series of 2 second hyperpolarizing and depolarizing steps

Series 1-6: Current Clamp, Series of 200 ms hyperpolarizing and depolarizing steps

Series 1-7: Current Clamp, Ramp protocol

Series 1-8: Voltage Clamp, Vhold -70, step to -90 to monitor access

Series 1-9: Voltage Clamp, Vhold -80, continuous recording to assess spontaneous EPSCs

Series 1-10: Voltage Clamp, Vhold -70, step to -90 to monitor access

Series 1-11: Voltage Clamp, Vhold -40, continuous recording to assess spontaneous IPSCs

Series 1-12: Voltage Clamp, Vhold -70, step to -90 to monitor access

Series 1-13: Current Clamp, Series of 200 ms small hyperpolarizing and depolarizing steps

Series 1-14: Current Clamp, Series of 500 µs hyperpolarizing steps

Series 1-15: Current Clamp, Series of 500 µs depolarizing steps

Series 1-16: Current Clamp, Series of 5 ms hyperpolarizing steps

Series 1-17: Current Clamp, Series of 5 ms depolarizing steps

May 23 IR1G

A pyramidal cell from an 8 month old wild-type mouse. The parent folder contains 18 sub-folders with data from different electrophysiological series as follows:

Series 1-1: Voltage Clamp, Vhold -70 mV, step to -90 mV to monitor access

Series 1-2: Voltage Clamp, IV relation, -120 to +20 mV steps

Series 1-3: Voltage Clamp, protocol to evoke slow afterhyperpolarization current

Series 1-4: Voltage Clamp, Vhold -70, step to -90 to monitor access

Series 1-5: Current Clamp, Series of 2 second hyperpolarizing and depolarizing steps

Series 1-6: Current Clamp, Series of 200 ms hyperpolarizing and depolarizing steps

Series 1-7: Current Clamp, Series of 200 ms small hyperpolarizing and depolarizing steps

Series 1-8: Current Clamp, Ramp protocol

Series 1-9: Voltage Clamp, Vhold -70, step to -90 to monitor access

Series 1-10: Voltage Clamp, Vhold -80, continuous recording to assess spontaneous EPSCs

Series 1-11: Voltage Clamp, Vhold -70, step to -90 to monitor access

Series 1-12: Voltage Clamp, Vhold -40, continuous recording to assess spontaneous IPSCs

Series 1-13: Voltage Clamp, Vhold -70, step to -90 to monitor access

Series 1-14: Current Clamp, Series of 500 µs hyperpolarizing steps

Series 1-15: Current Clamp, Series of 500 µs depolarizing steps

Series 1-16: Current Clamp, Series of 5 ms hyperpolarizing steps

Series 1-17: Current Clamp, Series of 5 ms depolarizing steps

Series 1-18: Current Clamp, Series of 2 s hyperpolarizing and depolarizing steps