Hungarian National Research Fund grants OTKA(K119443)
(K137886)
(PD121123)
Szakterületek:
Egyéb természettudományok
Knowledge about the activity of single neurons is essential in understanding the mechanisms
of synchrony generation, and particularly interesting if related to pathological conditions.
The generation of interictal spikes-the hypersynchronous events between seizures-is
linked to hyperexcitability and to bursting behaviour of neurons in animal models.
To explore its cellular mechanisms in humans we investigated the activity of clustered
single neurons in a human in vitro model generating both physiological and epileptiform
synchronous events. We show that non-epileptic synchronous events resulted from the
finely balanced firing of excitatory and inhibitory cells, which was shifted towards
an enhanced excitability in epileptic tissue. In contrast, interictal-like spikes
were characterised by an asymmetric overall neuronal discharge initiated by excitatory
neurons with the presumptive leading role of bursting pyramidal cells, and possibly
terminated by inhibitory interneurons. We found that the overall burstiness of human
neocortical neurons is not necessarily related to epilepsy, but the bursting behaviour
of excitatory cells comprising both intrinsic and synaptically driven bursting is
clearly linked to the generation of epileptiform synchrony.
