Investigating antipsychotic compound interactions with GABAA receptors in primary hippocampal neurons

This study aimed to establish protocols for testing compound effects in primary hippocampal neurons, with a sub-focus on GABA-elicited effects. Dissociated primary mouse neurons are excellent modelling systems for neurobiological, biophysical, and pharmacological evaluations. The presence of a wide variety of ion channels and receptors ensures a physiologically relevant analysis of cell response and signalling. Patch clamp provides direct functional, temporal and spatial information of a cell’s electrical and signalling properties. In addition, the Qube automated patch clamp (APC) platform enables a high throughput screening (HTS) by recording 384 cells simultaneously.

Several findings have led us to investigate further the relevance of the inhibiting actions of antipsychotic medications on GABAergic activity. Here we show data on:

• HEK cells expressing α5-containing GABAA receptors and primary hippocampal neurons were used to screen a small library of antipsychotics.
• Isolated primary hippocampal neurons from mice were patched on the Qube 384 APC system. Using an optimized cell dissociation protocol to obtain healthy cell membranes for patch-clamp, we obtained a whole-cell success rate of up to 65%.
  The effect of 12 GABA receptor modulators on responses to sub-μM GABA concentrations (0.5 μM GABA) and found most inhibiting GABA currents, ranging from weak to full inhibition.
• The modulators showed similar results in α5β3γ2 GABAA receptors in HEK cells.