PMID- 27382359
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20160706
LR  - 20201001
IS  - 1226-4512 (Print)
IS  - 1226-4512 (Linking)
VI  - 20
IP  - 4
DP  - 2016 Jul
TI  - Facilitation of AMPA receptor-mediated steady-state current by extrasynaptic NMDA 
      receptors in supraoptic magnocellular neurosecretory cells.
PG  - 425-32
LID - 10.4196/kjpp.2016.20.4.425 [doi]
AB  - In addition to classical synaptic transmission, information is transmitted 
      between cells via the activation of extrasynaptic receptors that generate 
      persistent tonic current in the brain. While growing evidence supports the 
      presence of tonic NMDA current (INMDA) generated by extrasynaptic NMDA receptors 
      (eNMDARs), the functional significance of tonic INMDA in various brain regions 
      remains poorly understood. Here, we demonstrate that activation of eNMDARs that 
      generate INMDA facilitates the alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionate 
      receptor (AMPAR)-mediated steady-state current in supraoptic nucleus (SON) 
      magnocellular neurosecretory cells (MNCs). In low-Mg(2+) artificial cerebrospinal 
      fluid (aCSF), glutamate induced an inward shift in Iho lding (IGLU) at a holding 
      potential (Vholding) of -70 mV which was partly blocked by an AMPAR antagonist, 
      NBQX. NBQX-sensitive IGLU was observed even in normal aCSF at Vholding of -40 mV 
      or -20 mV. IGLU was completely abolished by pretreatment with an NMDAR blocker, 
      AP5, under all tested conditions. AMPA induced a reproducible inward shift in 
      Iholding (IAMPA) in SON MNCs. Pretreatment with AP5 attenuated IAMPA amplitudes 
      to ~60% of the control levels in low-Mg(2+) aCSF, but not in normal aCSF at 
      Vholding of -70 mV. IAMPA attenuation by AP5 was also prominent in normal aCSF at 
      depolarized holding potentials. Memantine, an eNMDAR blocker, mimicked the 
      AP5-induced IAMPA attenuation in SON MNCs. Finally, chronic dehydration did not 
      affect IAMPA attenuation by AP5 in the neurons. These results suggest that tonic 
      INMDA, mediated by eNMDAR, facilitates AMPAR function, changing the postsynaptic 
      response to its agonists in normal and osmotically challenged SON MNCs.
FAU - Pai, Yoon Hyoung
AU  - Pai YH
AD  - Department of Physiology, Brain Research Institute, School of Medicine, Chungnam 
      National University, Daejeon 35015, Korea.
FAU - Lim, Chae Seong
AU  - Lim CS
AD  - Department of Anesthesiology & Pain Medicine, Brain Research Institute, School of 
      Medicine, Chungnam National University, Daejeon 35015, Korea.
FAU - Park, Kyung-Ah
AU  - Park KA
AD  - Department of Physiology, Brain Research Institute, School of Medicine, Chungnam 
      National University, Daejeon 35015, Korea.
FAU - Cho, Hyun Sil
AU  - Cho HS
AD  - Department of Physiology, Brain Research Institute, School of Medicine, Chungnam 
      National University, Daejeon 35015, Korea.
FAU - Lee, Gyu-Seung
AU  - Lee GS
AD  - Department of Physiology, Brain Research Institute, School of Medicine, Chungnam 
      National University, Daejeon 35015, Korea.
FAU - Shin, Yong Sup
AU  - Shin YS
AD  - Department of Anesthesiology & Pain Medicine, Brain Research Institute, School of 
      Medicine, Chungnam National University, Daejeon 35015, Korea.
FAU - Kim, Hyun-Woo
AU  - Kim HW
AD  - Department of Physiology, Brain Research Institute, School of Medicine, Chungnam 
      National University, Daejeon 35015, Korea.
FAU - Jeon, Byeong Hwa
AU  - Jeon BH
AD  - Department of Physiology, Brain Research Institute, School of Medicine, Chungnam 
      National University, Daejeon 35015, Korea.
FAU - Yoon, Seok Hwa
AU  - Yoon SH
AD  - Department of Anesthesiology & Pain Medicine, Brain Research Institute, School of 
      Medicine, Chungnam National University, Daejeon 35015, Korea.
FAU - Park, Jin Bong
AU  - Park JB
AD  - Department of Physiology, Brain Research Institute, School of Medicine, Chungnam 
      National University, Daejeon 35015, Korea.
LA  - eng
PT  - Journal Article
DEP - 20160623
PL  - Korea (South)
TA  - Korean J Physiol Pharmacol
JT  - The Korean journal of physiology & pharmacology : official journal of the Korean 
      Physiological Society and the Korean Society of Pharmacology
JID - 9709505
PMC - PMC4930911
OTO - NOTNLM
OT  - AMPA receptors
OT  - Chronic dehydration
OT  - Extrasynaptic NMDA receptors
OT  - Magnocellular neurosecretory cells
COIS- CONFLICTS OF INTEREST: The authors declare no conflicts of interest.
EDAT- 2016/07/07 06:00
MHDA- 2016/07/07 06:01
PMCR- 2016/07/01
CRDT- 2016/07/07 06:00
PHST- 2016/03/28 00:00 [received]
PHST- 2016/06/06 00:00 [revised]
PHST- 2016/06/09 00:00 [accepted]
PHST- 2016/07/07 06:00 [entrez]
PHST- 2016/07/07 06:00 [pubmed]
PHST- 2016/07/07 06:01 [medline]
PHST- 2016/07/01 00:00 [pmc-release]
AID - 10.4196/kjpp.2016.20.4.425 [doi]
PST - ppublish
SO  - Korean J Physiol Pharmacol. 2016 Jul;20(4):425-32. doi: 
      10.4196/kjpp.2016.20.4.425. Epub 2016 Jun 23.