Preserved neurotransmitter receptor binding following ischemia in preconditioned gerbil brain.
Preconditioning the brain with sublethal ischemia induces tolerance to subsequent ischemic insult. Using [3H]quinuclidinyl benzilate (QNB), [3H]MK 801, [3H]cyclohexyladenosine, [3H]muscimol, and [3H]PN200-110, we investigated the alterations in neurotransmitter receptor and calcium channel binding in the gerbil hippocampus following ischemia with or without preconditioning. Two-minute forebrain ischemia, which produced no neuronal damage, resulted in no alterations in binding except for a slight reduction in [3H]QNB binding in the CA1 subfield. Three-minute ischemia destroyed the majority of CA1 pyramidal cells and caused, in CA1, reductions in binding of all ligands used. Preconditioning with 2-min ischemia followed by 4 days of reperfusion protected against CA1 neuronal damage and prevented the reductions in binding although [3H]QNB and [3H]PN200-110 binding transiently decreased in the early reperfusion period, suggesting down-regulation. Thus, preconditioning protects against damage to the neurotransmission system as well as histopathological neuronal death.
Kato
H
H
Department of Neurology, Tohoku University School of Medicine, Sendai, Japan.
Araki
T
T
Kogure
K
K
D000241:Adenosine / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D002545:Brain Ischemia / Q000378:metabolism*; D003213:Conditioning, Psychological / Q000502:physiology*; D016291:Dizocilpine Maleate / Q000378:metabolism; D015536:Down-Regulation; D005849:Gerbillinae; D006624:Hippocampus / Q000033:anatomy & histology / Q000378:metabolism; D017275:Isradipine / Q000378:metabolism; D008297:Male; D009118:Muscimol / Q000378:metabolism; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D017981:Receptors, Neurotransmitter / Q000378:metabolism*
D017981:Receptors, Neurotransmitter; D009118:Muscimol; C027513:N(6)-cyclohexyladenosine; D011813:Quinuclidinyl Benzilate; D016291:Dizocilpine Maleate; D000241:Adenosine; D017275:Isradipine