Local Field Potential Recording in Submerged Slices

Local Field Potential (LFP) recordings were done in a submerged chamber, and slices were placed on a mesh that allowed perfusion on both sides at a high flow rate (10–30 ml/min) (Hajos and Mody, 2009 (link); Maier et al., 2009 (link)). All recordings were done with low resistance glass microelectrodes (∼150 kΩ tip resistance). The electrodes were pulled with a Sutter P87 puller with six controlled pulls and filled with 0.5 M NaCl in 1% agar, which prevents leakage of the electrode solution that could potentially alter the tissue surrounding the electrode tip. The recording electrode was placed in CA1 stratum pyramidale, where SWs have large amplitudes (Maier et al., 2009 (link)) in healthy slices.