Figure 2.

Intracellular Cl concentration and electrical activity strongly depend on the experimental model and conditions. (A) The mean intracellular Cl concentration in neurons at different depth from the surface in the intact hippocampi () and acute hippocampal slice preparations (◯) at P5–P7. Note the highly elevated Cl concentrations in neurons from the surface layers in the slice preparation (Modified from Dzhala et al., 2012). (B) The effects of slicing conditions on intracellular Cl concentration. Mean Cl_i as a function of depth in the hippocampal slices prepared from P5–P7 mice in control ACSF and in a high sucrose solution (Modified from Dzhala et al., 2012). (C–E) Genesis of network events and amplitude of local field potentials strongly depend upon the flow rate of ACSF. (C) Spontaneous network activity recorded at a low flow rate of 1.9 ml/min (left), and a high flow rate of 5.2 ml/min (right). Note sharp wave–ripple activity only at a high flow rate. Juvenile (P14–P20) transverse hippocampal 400–450 μm thick slices from Wistar rats were used here (from Hájos et al., 2009). (D) Examples of local field potentials measured in the same slice and electrode positions at different flow rates. Note the remarkable increase in amplitude when the flow rate is increased. (E) Summary of the dependence of local field potential (LFP) amplitudes on the oxygen levels and perfusion rates. Slices 400 μm thick from P4–P7 Swiss mice (from Ivanov et al., 2011).