title: Dexmedetomidine promotes the recovery of the field excitatory postsynaptic potentials (fEPSPs) in rat hippocampal slices exposed to oxygen-glucose deprivation.
abstract: Dexmedetomidine (DEX), a selective α2 adrenergic agonist, is an anesthetic and sedative agent, and is reported to exert neuroprotective effects after hypoxic ischemia. However, there are few studies on the electrophysiological effect of DEX in hippocampal slices under ischemic conditions. The effects of DEX on field potential in hippocampal slices exposed to oxygen-glucose deprivation (OGD) were evaluated. Hippocampal slices were prepared from rats, and the evoked field excitatory postsynaptic potentials (fEPSPs) were recorded using the MED 64 system. Hypoxic-ischemia was induced by perfusion with glucose-free artificial cerebrospinal fluid (aCSF) bubbled with 95% N2 and 5% CO2, and hippocampal slices were perfused with DEX-added aCSF before, during, and after OGD induction. In the normal hippocampal slices, perfusion with 1 and 10μM DEX did not significantly decrease the normalized fEPSP amplitude, but 100μM DEX significantly reduced the fEPSP amplitude compared with its baseline control. The induction of OGD remarkably decreased the fEPSP amplitude, whereas the pre-, co-, and post-treatment of 10μM DEX gradually promoted recovery after washing out, and consequently the amplitude of fEPSP in DEX pre-, co-, and post-treated OGD slices were significantly higher than that in the untreated OGD slices at 10min and 60min after washing out. In particular, co-treatment with DEX conspicuously promoted the recovery of the fEPSP amplitude at the beginning of washing out. These results suggest the possibility of DEX as a therapeutic agent to prevent hypoxic-ischemic brain damage and promote functional recovery after ischemia.
authors.affiliation: Department of Physiology, Kyung Hee University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sung-Eun
authors.initials: SE
authors.lastname: Kim
authors.affiliation: Department of Physiology, Kyung Hee University College of Medicine, Seoul, Republic of Korea.
authors.forename: Il-Gyu
authors.initials: IG
authors.lastname: Ko
authors.affiliation: Department of Physiology, Kyung Hee University College of Medicine, Seoul, Republic of Korea.
authors.forename: Chang-Ju
authors.initials: CJ
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jun-Young
authors.initials: JY
authors.lastname: Chung
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jae-Woo
authors.initials: JW
authors.lastname: Yi
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kyung Hee Medical Center, Kyung Hee University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jeong-Hyun
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kyung Hee Medical Center, Kyung Hee University College of Medicine, Seoul, Republic of Korea.
authors.forename: Myung-Soo
authors.initials: MS
authors.lastname: Jang
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kyung Hee Medical Center, Kyung Hee University College of Medicine, Seoul, Republic of Korea. Electronic address: esthesi@khu.ac.kr.
authors.forename: Jin-Hee
authors.initials: JH
authors.lastname: Han
mesh_terms: D000818:Animals; D015687:Cell Hypoxia; D020927:Dexmedetomidine / Q000008:administration & dosage*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects*; D005947:Glucose / Q000172:deficiency; D006624:Hippocampus / Q000187:drug effects* / Q000503:physiopathology; D020925:Hypoxia-Ischemia, Brain / Q000503:physiopathology* / Q000517:prevention & control; D008297:Male; D018696:Neuroprotective Agents / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018696:Neuroprotective Agents; D020927:Dexmedetomidine; D005947:Glucose
keywords: Dexmedetomidine; Field excitatory postsynaptic potential; Hypoxic-ischemia; Neuroprotection; Oxygen-glucose deprivation