Kindled seizure-evoked somatostatin release in the hippocampus: inhibition by MK-801.
The aim of this study was to evaluate the contribution of ionotropic glutamate receptors to kindled seizure-evoked somatostatin release in the hippocampus, using a microdialysis approach. Basal and amygdala stimulation-evoked somatostatin-like immunoreactivity (-LI) release was significantly greater in kindled compared to naive rats. In naive rats, neither hippocampal perfusion with the selective AMPA/kainate receptor antagonist GYKI 52466 nor with the selective NMDA receptor antagonist MK-801 affected behavior, EEG, or somatostatin-LI release. In kindled rats, GYKI 52466 was still devoid of any effect, while MK-801 significantly decreased stimulus-evoked (but not basal) somatostatin-LI efflux. MK-801 produced identical effects when injected i.p. This study provides the first direct evidence that kindled seizure-evoked somatostatin release in the hippocampus is partly NMDA receptor dependent.
Marti
M
M
Dipartimento di Medicina Clinica e Sperimentale, Università di Ferrara, Italy.
Bregola
G
G
Binaschi
A
A
Gemignani
A
A
Simonato
M
M
D000679:Amygdala / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D004195:Disease Models, Animal; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D004558:Electric Stimulation / Q000009:adverse effects; D004827:Epilepsy / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D007696:Kindling, Neurologic / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors / Q000378:metabolism; D018092:Kainic Acid Receptors / Q000037:antagonists & inhibitors / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012640:Seizures / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D013004:Somatostatin / Q000378:metabolism*
D016291:Dizocilpine Maleate; D018691:Excitatory Amino Acid Antagonists; D018698:Glutamic Acid; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; D016194:Receptors, N-Methyl-D-Aspartate; D013004:Somatostatin