Summary
Application of phosphoethanolamine (PEA; more than 1 m.M) to rat hippocampal neurons leads to a change in excitability in two phases: a) A transient increase of EPSP amplitude and membrane input resistance (R i) in the order of minutes that can be observed after local as well as bath application, b) Decrease of EPSP and IPSP amplitude and ofR i are caused by exposure to PEA (over 1 m.M; bath application) for more than 20 min.
Membrane potential and action potential are not changed by 10 m.M PEA for up to half an hour.
Depolarizations evoked by N-methyl-D,L-aspartate (NMA) given locally are transiently enhanced and then reduced by PEA following a time course similar to the effects a) and b) observed on EPSPs.
PEA produces an apparent decrease of calcium activity due to its electrochemical properties. A local application into the soma layer results in a complex calcium signal. A shortlasting drop in calcium activity is followed by a large positive signal indicating an increase of calcium activity.
It is concluded that liberation of PEA exacerbates rather than mitigates the harmful consequences of strong excitation and/or excitotoxins.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- APV :
-
D-2-amino-5-phosphono-valeric acid
- NMA :
-
N-methyl-D,L-aspartate
- PEA :
-
phosphoethanolamine
- R i :
-
membrane input resistance
References
Bonhaus DW, Lippincott SE, Huxtable RJ (1984) Subcellular distribution of neuroactive amino acids in brains of genetically epileptic rats. Epilepsia 25:564–568
Curtis DR, Watkins JC (1960) The excitation and depression of spinal neurones by structurally related compounds. J Neurochem 6:117–141
Dietzel I, Heinemann U, Hofmeier G, Lux HD (1982) Changes in the extracellular volume in the cerebral cortex of cats in relation to stimulus induced epileptiform after discharges. In: Klee MR, Lux HD, Speckmann EJ (eds) Physiology and pharmacology of epileptogenic phenomena. Raven Press, New York, pp 5–12
Dingledine R (1983) N-methyl aspartate activates voltage-dependent calcium conductance in rat hippocampal pyramidal cells. J Physiol (Lond) 343:385–405
Dingledine R, Somjen G (1981) Calcium dependence of synaptic transmission in the hippocampal slice. Brain Res 207:218–222
Essmann WB (1974) Regional alterations of synaptic O-phosphoryl-ethanolamine in differentially housed mice. Pharmacol Res Commun 6:377–395
Geiger H, Singer W (1982) The role of Ca++-ions in developmental plasticity of cat striate cortex. Int J Develop Neurosci Suppl R328
Hablitz JJ (1985) Action of excitatory amino acids and their antagonists on hippocampal neurons. Cell Mol Neurobiol 5:389–405
Heinemann U (1986) Excitatory amino acid and epilepsy induced changes in extracellular space size.In: Schwarcz R, Ben Ari Y (eds) Excitatory amino acids and epilepsy. Plenum Press, New York, pp 449–460
Klee MR, Misgeld U, Zeise ML (1981) Pharmacological differences between CA3 and dentate granule cells in hippocampal slices. In: Feher O, Joo F (eds) Cellular analogues of conditioning and neural plasticity. Adv Physiol Sci 36:Akademiai Kiado, Budapest, pp 155–164
Lehmann A, Isacsson H, Hamberger A (1983) Effects of in vivo administration of kainic acid on the extracellular amino acid pool in the rabbit hippocampus. J Neurochem 40:1314–1320
Lehmann A, Hagberg H, Jacobson I, Hamberger A (1985a) Effects of status epilepticus on extracellular amino acids in the hippocampus. Brain Res 359:147–151
Lehmann A, Lazarewicz JW, Zeise M (1985b) N-Methylaspartate-evoked liberation of taurine and phosphoethanolamine in vivo: site of release. J Neurochem 45:1172–1177
Lehmann A, Laird HE, Huxtable RJ (1986) Electroencephalographic effects of centrally administered phosphoethanolamine and glutamic acid. Proc West Pharmacol Soc 29:227–231
Lehmann A, Hamberger A (1984) A possible interrelationship between extracellular taurine and phosphoethanolamine in the hippocampus. J Neurochem 42:1286–1290
Llinás R, Yarom Y (1981) Properties and distribution of ionic conductances generating electroresponsiveness of mammalian inferior olivary neurones in vitro. J Physiol (Lond) 315:569–584
Vezzani A, Ungerstedt U, French ED, Schwarcz R (1985) In vivo brain dialysis of amino acids and simultaneous EEG measurements following intrahippocampal quinolinic acid injection: Evidence for a dissociation between neurochemical changes and seizures. J Neurochem 45:335–344
Zeise ML (1985) Taurine on hippocampal slices: Comparison to GABA and glycine, and antagonism by 4-aminopyridine. In: Oja SS, Kontro P (eds) Taurine: Biological actions and clinical perspectives. Alan R Liss, New York, pp 281–287
Zeise ML, Geiger H (1985) Effects of taurine on electrophysiological properties and calcium conductivities in hippocampal cells of the rat in vitro. Pflügers Arch 405: R44
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Zeise, M., Lehmannb, A. Phosphoethanolamine transiently enhances excitability of rat hippocampal neurons in vitro. J. Comp. Physiol. 161, 461–467 (1987). https://doi.org/10.1007/BF00603971
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00603971