Pharmacological characterization of phosphoinositide-linked glutamate receptor excitation of hippocampal neurons

Stratton, Kathleen R.; Worley, Paul F.; Baraban, Jay M.

doi:10.1016/0014-2999(90)90461-e

Cited by 66 publications

(31 citation statements)

References 10 publications

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“…Recently several competitive metabotropic antagonists have become available, but the antagonists are of relatively low potency and may not be effective at all subtypes of metabotropic receptors (Hayashi et at. 1994 (Stratton, Worley & Baraban, 1990), depression of synaptic responses by metabotropic agonists in olfactory neurons has recently been reported to occur through a PTX-sensitive mechanism (Trombley & Westbrook, 1992 Figure 11 shows the results of these experiments. As reported previously in slice and other culture preparations (Forsythe & Clements, 1990;Baskys & Malenka, 1991), activation of metabotropic receptors depressed autaptic responses in cells untreated with PTX ( Fig.…”

mentioning

confidence: 71%

Paired‐pulse modulation of fast excitatory synaptic currents in microcultures of rat hippocampal neurons.

Mennerick

Zorumski

1995

The Journal of Physiology

137

107

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1. Paired-pulse modulation of excitatory non-N-methyl-D-aspartate (non-NMDA) receptormediated autaptic currents and conventional monosynaptic (interneuronal) excitatory postsynaptic currents (EPSCs) was investigated in microcultures of rat hippocampal neurons, where polysynaptic influences are eliminated. 2. Most autaptic currents and EPSCs exhibited paired-pulse depression in response to paired stimuli. Depression was sensitive to the level of transmitter release, which was varied by manipulating extracellular Ca2+ and Mg2+ concentrations. Paired-pulse facilitation emerged in many cells at low levels of transmitter release. 3. Paired-pulse depression and facilitation could be differentially expressed at two distinct postsynaptic targets of a single presynaptic cell, and the form of modulation was not dependent upon the transmitter phenotype of the postsynaptic cell. 4. Paired-pulse depression recovered exponentially with a time constant of -5 s, although in most neurons a much faster component of recovery was detected. Recovery from pairedpulse facilitation was well described by a single exponential of 380 + 57 ms. 5. Under conditions of robust paired-pulse depression of evoked responses, spontaneous autaptic and postsynaptic currents (sEPSCs, presumed miniature EPSCs) occurred at an enhanced frequency immediately following evoked responses. The decay of the frequency increase mirrored the time course of recovery from paired-pulse facilitation of evoked responses examined under conditions of reduced transmitter release. 6. Several lines of evidence suggested a large presynaptic component to paired-pulse depression. In eight out of nine cells no depression in sEPSC amplitudes was detected following conditioning stimulation. Simultaneously recorded glial glutamate uptake currents showed depression similar to neuronal evoked EPSCs. Finally, NMDA receptormediated EPSC paired-pulse depression at positive potentials was similar to non-NMDA EPSC depression. 7. Neither adenosine nor glutamate feedback onto presynaptic receptors is likely to mediate paired-pulse depression, because neither competitive nor non-competitive inhibitors of the actions of these agents diminished paired-pulse depression.The nervous system relays much of its information via trains of impulses. Because the efficacy of synaptic transmission at many synapses can be altered by the frequency of impulse trains, an understanding of the properties of frequency-dependent modulation of synaptic responses should yield insights into the nature of information processing in the nervous system. Frequency-dependent synaptic modulation in its simplest form has been studied using paired-pulse stimulation protocols. Paired-pulse depression and paired-pulse facilitation, among other forms of short-term modulation, have been well characterized at the vertebrate neuromuscular junction largely because of the simplicity and accessibility of the preparation (del Castillo & Katz, 1954;Takeuchi, 1958

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mentioning

confidence: 71%

Paired‐pulse modulation of fast excitatory synaptic currents in microcultures of rat hippocampal neurons.

Mennerick

Zorumski

1995

The Journal of Physiology

137

107

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“…6 E, closed symbols and bars) with respect to that of astrocytes that did not open symbols and bars). It is noteworthy that the average increase at the second t-AC PD application in astrocytes responsive to neuronal stimulation was higher than that observed after three successive t-AC PD applications (114% vs 44.7%; (Stratton et al, 1990) and (2) t-AC PD-induced release of glutamate from astrocytes with activation of neuronal ionotropic glutamate receptors (iGluR), i.e., AM PA and NMDARs. Indeed, cultured astrocytes have been reported to release glutamate and excite adjacent neurons (Parpura et al, 1994a;Jeftinija et al, 1996).…”

Section: Neuronal Stimulation Modulates the Frequency Of Oscillationsmentioning

confidence: 93%

Intracellular Calcium Oscillations in Astrocytes: A Highly Plastic, Bidirectional Form of Communication between Neurons and AstrocytesIn Situ

et al. 1997

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The spatial-temporal characteristics of intracellular calcium ([Ca 2ϩ ] i ) changes elicited in neurons and astrocytes by various types of stimuli were investigated by means of confocal fluorescent microscopy in acute rat brain slices loaded with the Ca 2ϩ indicator indo-1. Neurons and astrocytes from the visual cortex and CA1 hippocampal region were identified in situ on the basis of their morphological, electrophysiological, and pharmacological features. We show here that stimulation of neuronal afferents triggered periodic [Ca 2ϩ ] i oscillations in astrocytes. The frequency of these oscillations was under a dynamic control by neuronal activity as it changed according to the pattern of stimulation. After repetitive episodes of neuronal stimulation as well as repetitive stimulation with a metabotropic glutamate receptor agonist, astrocytes displayed a long-lasting increase in [Ca 2ϩ ] i oscillation frequency. Oscillating astrocytes were accompanied by repetitive [Ca 2ϩ ] i elevations in adjacent neurons, most likely because of the release of glutamate via a tetanus toxin-resistant process. These results reveal that [Ca 2ϩ ] i oscillations in astrocytes represent a highly plastic signaling system that underlies the reciprocal communication between neurons and astrocytes.

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“…Furthermore, it is well known that some of the effects of these receptors are pertussis toxin-sensitive [9,12,14,40] and some others are not [9,41,42], depending on the cell type studied. The effect of PTX on mGluR binding was investigated by treatment of bovine brain coated vesicles with 1 ,ug PTX/lOO ,ug protein, prior to the QA competition binding experiments.…”

Section: Resultsmentioning

confidence: 99%

Characterization of metabotropic glutamate receptors coupled to a pertussis toxin sensitive G‐protein in bovine brain coated vesicles

1993

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Glutamate metabotropic receptors (mGluRs) in bovine brain coated vesicles have been characterized by pharmacological and kinetic binding experiments. Saturation experiments revealed a single binding site with a Kd = 607.9 f 78.5 nM and a B,,,,, = 6.45 f 0.88 pmol/mg protein. The specific binding of Lj3H]glutamate to mGluRs is regulated by guanine nucleotides. Guanosine-5'-triphosphate (GTP; 100 PM) shifts the agonist competition curves to the right, increasing the XC, values. Pertussis toxin treatment produces a pharmacological binding profile for quisqualate similar to that obtained in the presence of 1OOpM GTP. These results indicate the presence of metabotropic glutamate receptors in coated vesicles and its coupling to a pertussis toxin sensitive G-protein.

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Pharmacological characterization of phosphoinositide-linked glutamate receptor excitation of hippocampal neurons

Cited by 66 publications

References 10 publications

Paired‐pulse modulation of fast excitatory synaptic currents in microcultures of rat hippocampal neurons.

Paired‐pulse modulation of fast excitatory synaptic currents in microcultures of rat hippocampal neurons.

Intracellular Calcium Oscillations in Astrocytes: A Highly Plastic, Bidirectional Form of Communication between Neurons and AstrocytesIn Situ

Characterization of metabotropic glutamate receptors coupled to a pertussis toxin sensitive G‐protein in bovine brain coated vesicles

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