Homo- and heterosynaptic long-term potentiation in the medial cortex of the turtle brain in vitro.
Long-term potentiation of excitatory synaptic transmission was studied in an in vitro turtle brain that manifests spontaneous electrocorticogram activity. We show that in the turtle medial cortex, there is evidence of homosynaptic long-term potentiation in the septum-medial cortex pathway. This potentiation has two components, one dependent on NMDA receptor activation and the other independent of this receptor and suppressed by nifedipine, an antagonist of voltage-dependent Ca2+ channels (VDCCs), as occurs in the CA1 of rat hippocampus. Heterosynaptic long-term potentiation was also found in the medial cortex, as a tetanus in the septum also increased the cortico medial-cortico medial response. The intracellular response of pyramidal cells showed that the medial cortex EPSP increased its amplitude paripassu with an increase in the response of evoked field potential after tetanic stimulation in the septum.
Neurología Experimental (Unidad Asociada al CSIC), Dpto. Investigación, Hospital Ramón y Cajal, Ctra. Colmenar Km 9, 28034, Madrid, Spain. dolores.munoz@hrc.es
M D
MD
Muñoz
J M
JM
Gaztelu
E
E
García-Austt
D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D004558:Electric Stimulation; D004569:Electroencephalography; D019706:Excitatory Postsynaptic Potentials; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000502:physiology*; D012688:Septum Pellucidum / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*; D014426:Turtles / Q000502:physiology*