  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.
