AMPA, NMDA and GABAA receptor mediated network burst dynamics in cortical cultures in vitro

In this work we study the excitatory AMPA, and NMDA, and inhibitory GABAA receptor mediated dynamical changes in neuronal networks of neonatal rat cortex in vitro. Extracellular network-wide activity was recorded with 59 planar electrodes simultaneously under different pharmacological conditions. We analyzed the changes of overall network activity and network-wide burst frequency between baseline and AMPA receptor (AMPA-R) or NMDA receptor (NMDA-R) driven activity, as well as between the latter states and disinhibited activity. Additionally, spatiotemporal structures of pharmacologically modified bursts and recruitment of electrodes during the network bursts were studied. Our results show that AMPA-R and NMDA-R receptors have clearly distinct roles in network dynamics. AMPA-Rs are in greater charge to initiate network wide bursts. Therefore NMDA-Rs maintain the already initiated activity. GABAA receptors (GABAA-Rs) inhibit AMPA-R driven network activity more strongly than NMDA-R driven activity during the bursts.