Assessing neural circuit dynamics of antipsychotic drugs

Abstract

In vivo extracellular recording of simultaneous neural responses from different neurons at the same time allows to understand the interaction between neurons and to determine neural dynamics in different brain circuits. These neural responses are transmembrane currents that can be measured in the extracellular space with high temporal resolution (i.e. ms) by placing electrodes extracellularly. Spikes or action potentials are one of the major contributors to the extracellular signal. These are required for effective communication across different brain areas and abnormal spiking activity is found in some neurological diseases. Extracting spikes from extracellular recordings is an arduous task that requires to reliably discern spike contributions from different neurons recorded near the electrode from the background electrical noise. Here, multi-unit activity (i.e. aggregate spiking activity of a neural population close to the electrode) is quantified to assess neural circuit dynamics of antipsychotic drugs in freely-moving mice in the prefronto-hippocampal circuit. Results show that multi-unit activity is reduced by antipsychotic drugs both in hippocampus and medial prefrontal cortex. Decrease in the firing rate of neuronal populations seems to be mediated mainly by the stimulation of serotonin 1A receptor and/or blockage of serotonin 2A receptor.