Biomaterial Database

Effects of flufenamic acid on fictive locomotion, plateau potentials, calcium channels and NMDA receptors in the lamprey spinal cord. 2006

Di Wang, and Sten Grillner, and Peter Wallén

Department of Neuroscience, Nobel Institute for Neurophysiology, Karolinska Institute, SE-171 77 Stockholm, Sweden.

A Ca(2+)-activated, non-selective cation current (I(CAN)) has been suggested to contribute to plateau potentials in lamprey reticulospinal neurons, providing the drive for locomotor initiation. Flufenamic acid (FFA) is commonly used as a blocker of I(CAN). To explore the effects of FFA on spinal locomotor pattern generation, we induced fictive locomotion in the isolated lamprey spinal cord. Bath-applied FFA (100-200microM) caused a marked reduction of amplitude and regularity of the locomotor burst activity. We next analyzed the NMDA-induced membrane potential oscillations in single spinal neurons. The duration of depolarizing plateaus was markedly reduced when applying FFA, suggesting an involvement of I(CAN). However, in experiments with intracellular injection of the Ca(2+) chelator BAPTA, and in the presence of the K(Ca)-channel blocker apamin, no support was found for an involvement of I(CAN). We therefore explored alternative explanations of the effects of FFA. FFA reduced the size of the slow, Ca(2+)-dependent afterhyperpolarization, suggesting an influence on calcium channels. FFA also reduced the NMDA component of reticulospinal EPSPs as well as NMDA-induced depolarizing responses, demonstrating an influence on NMDA receptors. These non-selective effects of FFA can account for its influence on fictive locomotion and on membrane potential oscillations and thus, a specific involvement of the I(CAN) current in the lamprey spinal cord is not supported.

UI	MeSH Term	Description	Entries
D007798	Lampreys	Common name for the only family (Petromyzontidae) of eellike fish in the order Petromyzontiformes. They are jawless but have a sucking mouth with horny teeth.	Eels, Lamprey,Petromyzontidae,Petromyzontiformes,Eel, Lamprey,Lamprey,Lamprey Eel,Lamprey Eels
D008124	Locomotion	Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.	Locomotor Activity,Activities, Locomotor,Activity, Locomotor,Locomotor Activities
D008297	Male		Males
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D002614	Chelating Agents	Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.	Chelating Agent,Chelator,Complexons,Metal Antagonists,Chelators,Metal Chelating Agents,Agent, Chelating,Agents, Chelating,Agents, Metal Chelating,Antagonists, Metal,Chelating Agents, Metal
D004533	Egtazic Acid	A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.	EGTA,Ethylene Glycol Tetraacetic Acid,EGATA,Egtazic Acid Disodium Salt,Egtazic Acid Potassium Salt,Egtazic Acid Sodium Salt,Ethylene Glycol Bis(2-aminoethyl ether)tetraacetic Acid,Ethylenebis(oxyethylenenitrile)tetraacetic Acid,GEDTA,Glycoletherdiamine-N,N,N',N'-tetraacetic Acid,Magnesium-EGTA,Tetrasodium EGTA,Acid, Egtazic,EGTA, Tetrasodium,Magnesium EGTA
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D005260	Female		Females
D005439	Flufenamic Acid	An anthranilic acid derivative with analgesic, anti-inflammatory, and antipyretic properties. It is used in musculoskeletal and joint disorders and administered by mouth and topically. (From Martindale, The Extra Pharmacopoeia, 30th ed, p16)	Dignodolin,Acid, Flufenamic