Article (Scientific journals)
Bicuculline methiodide potentiates NMDA-dependent burst firing in rat dopamine neurons by blocking apamin-sensitive Ca2+-activated K+ currents.
Johnson, S. W.; Seutin, Vincent
1997In Neuroscience Letters, 231 (1), p. 13-6
Peer Reviewed verified by ORBi
 

Files


Full Text
Johnson1997.pdf
Publisher postprint (185.03 kB)
Request a copy

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
Action Potentials/drug effects/physiology; Animals; Apamin/pharmacology; Bicuculline/analogs & derivatives/pharmacology; Calcium/pharmacology; Dopamine/physiology; Drug Synergism; Electrophysiology; Excitatory Amino Acid Agonists/pharmacology; GABA Antagonists/pharmacology; Ion Channel Gating/drug effects; Male; N-Methylaspartate/pharmacology; Neurons/chemistry/drug effects/physiology; Periodicity; Picrotoxin/pharmacology; Potassium/metabolism; Potassium Channels/metabolism; Rats; Rats, Sprague-Dawley; Receptors, GABA-A/antagonists & inhibitors; Substantia Nigra/chemistry/cytology/physiology; Tetrodotoxin/pharmacology; Ventral Tegmental Area/chemistry/cytology/physiology
Abstract :
[en] Apamin, a bee venom toxin which blocks a Ca2+-dependent K+ current, potentiates N-methyl-D-aspartate (NMDA)-induced burst firing in dopamine neurons. We now report that burst firing is also potentiated by an apamin-like effect of bicuculline methiodide (BMI) at the same concentration (30 microM) which blocks GABA(A) receptors in vitro. Using microelectrodes to record intracellularly from rat dopamine neurons in the midbrain slice, BMI reduced the apamin-sensitive afterhyperpolarization in all cells tested. BMI also mimicked apamin (100 nM) by potentiating burst firing produced by a concentration of NMDA (10 microM) which is too low to evoke burst firing when perfused alone. When recording under voltage-clamp, both BMI and apamin reduced a depolarization-activated outward current which was also sensitive to perfusate containing no-added Ca2+. Although picrotoxin (100 microM) and bicuculline free base (30 microM) blocked the inhibition of firing produced by the GABA(A) agonist isoguvacine (100 microM), neither had apamin-like effects. We conclude that BMI potentiates burst firing by blocking an apamin-sensitive Ca2+-activated K+ current.
Disciplines :
Pharmacy, pharmacology & toxicology
Author, co-author :
Johnson, S. W.
Seutin, Vincent ;  Université de Liège - ULiège > Département des sciences biomédicales et précliniques > Pharmacologie
Language :
English
Title :
Bicuculline methiodide potentiates NMDA-dependent burst firing in rat dopamine neurons by blocking apamin-sensitive Ca2+-activated K+ currents.
Publication date :
1997
Journal title :
Neuroscience Letters
ISSN :
0304-3940
eISSN :
1872-7972
Publisher :
Elsevier Scientific Publishers Ireland, Limerick, Ireland
Volume :
231
Issue :
1
Pages :
13-6
Peer reviewed :
Peer Reviewed verified by ORBi
Available on ORBi :
since 28 April 2010

Statistics


Number of views
97 (3 by ULiège)
Number of downloads
0 (0 by ULiège)

Scopus citations®
 
143
Scopus citations®
without self-citations
128
OpenCitations
 
118

Bibliography


Similar publications



Contact ORBi