Stimulation triggers endogenous activity patterns in cultured cortical networks.

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Dissociated cortical neuron cultures offer a balance between experimental realism and abstract modeling for studying synchronized neural activity.
• These networks exhibit spontaneous network bursts and quiescence, mimicking in vivo UP and DOWN states.
• Network bursts can be triggered by external stimulation, with propagation patterns observable via multi-channel micro-electrode arrays.

Purpose of the Study:

• To investigate the similarity between spontaneous and evoked activity patterns in rat cortical cultures.
• To determine if electrical stimulation elicits activity patterns comparable to spontaneous network bursts.
• To understand the underlying mechanisms driving the similarity between spontaneous and evoked neural activity.

Main Methods:

• Utilized rat cortical cultures integrated with multi-channel micro-electrode arrays.
• Applied electrical stimulation to various locations within the neural network.
• Analyzed and compared the spatial propagation patterns of spontaneous and evoked network bursts.

Main Results:

• Demonstrated a remarkable similarity in the rank order of electrodes during evoked and spontaneous activity events.
• Showed this similarity is independent of the electrical stimulation source location.
• Identified that stimulation effectively recruits highly active "leader" sites, which are rapidly activated in both spontaneous and evoked bursts.

Conclusions:

• Provides the first evidence for reliable similarity between spontaneous and evoked activity in dissociated cortical networks.
• Suggests that "leader" sites play a crucial role in organizing network activity, whether spontaneous or evoked.
• Highlights the utility of dissociated cortical cultures for studying fundamental principles of neural network dynamics.