GABAergic control of CA3-driven network events in the developing hippocampus.
Endogenous activity is a characteristic feature of developing neuronal networks. In the neonatal rat hippocampus, spontaneously occurring network events known as "Giant Depolarizing Potentials" (GDPs) are seen in vitro at a stage when GABAergic transmission is depolarizing. GDPs are triggered by the CA3 region and they are seen as brief recurrent events in field-potential recordings, paralleled by depolarization and spiking of pyramidal neurons. In the light of current data, GDPs are triggered by the glutamatergic pyramidal neurons which act as conditional pacemakers, while the depolarizing action of GABA plays a permissive role for the generation of these events in in vitro preparations. From an in vivo perspective, GDPs appear to be an immature form of hippocampal sharp waves.
Sipilä
Sampsa T
ST
Department of Biological and Environmental Sciences, University of Helsinki, P.O. Box 65, 00014 Helsinki, Finland.
Kaila
Kai
K
D000818:Animals; D000831:Animals, Newborn; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D006624:Hippocampus / Q000254:growth & development / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D017966:Pyramidal Cells / Q000254:growth & development / Q000502:physiology; D051381:Rats; D011963:Receptors, GABA-A / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid