The pharmacological properties of some crustacean neuronal acetylcholine, gamma‐aminobutyric acid, and L‐glutamate responses.

Marder, Eve; Paupardin‐Tritsch, Danièle

doi:10.1113/jphysiol.1978.sp012381

Cited by 166 publications

(123 citation statements)

References 38 publications

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“…The possibility that GABA may act by opening potassium channels gains additional support from invertebrate studies (Marder & Paupardin-Tritsch, 1978;Yarowski & Carpenter, 1978;Shimizu, Akaike, Oomura, Murahashi & Klee, 1983). The responses in the latter two studies were resistant to bicuculline and picrotoxin, respectively.…”

Section: Discussionmentioning

confidence: 98%

Comparison of the action of baclofen with gamma‐aminobutyric acid on rat hippocampal pyramidal cells in vitro.

Newberry¹

1985

The Journal of Physiology

451

182

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SUMMARY1. Intracellular recordings from CAI pyramidal cells in the hippocampal slice preparation were used to compare the action of baclofen, a y-aminobutyric acid (GABA) analogue, with GABA.2. Ionophoretic application of GABA or baclofen into stratum (s.) pyramidale evoked hyperpolarizations associated with reductions in the input resistance of the cell. Baclofen responses were easier to elicit in the dendrites than in the cell body layer. 5. The reversal potentials for the somatic GABA and baclofen responses were -70 mV and -85 mV respectively. When the membrane was depolarized, the baclofen response was reduced. This apparent voltage sensitivity was not seen with somatic GABA responses.6. Altering the chloride gradient across the cell membrane altered the reversal potential of the somatic GABA response but not that of the baclofen response. It was extrapolated that a tenfold shift in the extracellular potassium concentration would cause a 48 mV shift in the reversal potential of the baclofen response. Barium ions reduced the baclofen response, but not the GABA response.7. Orthodromic stimulation produced a fast inhibitory post-synaptic potential (i.p.s.p.) and a slow i.p.s.p. The properties of the fast and slow i.p.s.p.s were remarkably similar to those of the somatic GABA and baclofen responses, respectively.8. Application of GABA to the pyramidal cell dendrites evoked, in addition to a depolarization, two types of hyperpolarization. One type of hyperpolarization was * Present address: Merck Sharp and Dohme

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Section: Discussionmentioning

confidence: 98%

Comparison of the action of baclofen with gamma‐aminobutyric acid on rat hippocampal pyramidal cells in vitro.

Newberry¹

1985

The Journal of Physiology

451

182

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“…First, we stimulated the PD neurons in voltage clamp in control saline and recorded the compound AB/PD IPSPs (IPSP AB/PD ) in the follower neurons. We then stimulated the PD neurons while the preparation was superfused with 5 M picrotoxin (PTX), which blocks the glutamatergic synaptic release from the AB neuron (Marder and Paupardin-Tritsch, 1978). Thus, the IPSPs recorded in the follower neurons were those elicited solely by the PD neurons (IPSP PD ).…”

Section: Methodsmentioning

confidence: 99%

“…The biological synapses were then functionally removed from the network by the application of 5 M PTX [blocker of the glutamatergic AB, LP, and PY synapses (Marder and Paupardin-Tritsch, 1978)] and 1 mM TEA [blocker of the cholinergic PD and VD synapses ]. Note that this low concentration of TEA is not sufficient to significantly block potassium currents in these neurons (Graubard and Hartline, 1991;Kloppenburg et al, 1999;Peck et al, 2001).…”

Section: Methodsmentioning

confidence: 99%

Synaptic Dynamics Do Not Determine Proper Phase of Activity in a Central Pattern Generator

Rabbah¹,

Nadim²

2005

J. Neurosci.

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Rhythmic motor activity often requires neuronal output to the muscles to arrive in a particular sequence. At the pattern-generator level, this requires distinct activity phases in different groups of constituent neurons. The phase differences between rhythmically active neurons in a network are thought to arise from the interplay between their intrinsic properties and the temporal dynamics of synapses among these neurons. In the rhythmically active pyloric network of the lobster Panulirus interruptus, synaptic connections from the pacemaker ensemble to the follower neurons [lateral pyloric (LP) and pyloric constrictor (PY)] are thought to be primarily responsible for the proper phase of activity (pacemaker-LP-PY) across all frequencies (0.5-2 Hz) of the pyloric rhythm. We test this hypothesis by characterizing the synapses from the pacemaker ensemble to the LP and PY neurons. Paired comparisons show that these two synapses are not significantly different in strength or in the extent of short-term depression. To examine the level to which intrinsic properties of the follower neurons determine their relative activity phase, we block all chemical synapses within the network and drive the LP and PY neurons rhythmically using artificial synaptic currents with identical strength and dynamics implemented with the dynamic-clamp technique. In response to these identical synaptic inputs, the LP and PY neurons maintain the proper relative phase of activity. These results strongly indicate that the relative phase of activity among these follower neurons within the pyloric network is not dictated by their synaptic inputs but is solely determined by their distinct intrinsic properties.

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“…Additionally, in the stomatogastric ganglion of the crab, Cancer pagurus, GABA-activated chloride-conductance increases are insensitive to picrotoxin concentrations as high as 10-4M (Marder & Paupardin-Tritsch, 1978). We are interested in the possibility that the ability of picrotoxin to block GABA-activated chloride conductances may involve a site that is not functionally important to the anion permeation process.…”

Section: Introductionmentioning

confidence: 99%

A GABA‐activated chloride‐conductance not blocked by picrotoxin on spiny lobster neuromuscular preparations

Albert

Lingle

Marder

et al. 1986

British J Pharmacology

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1 Conductance increases to -y-aminobutyric acid (GABA) were recorded in the gm6b and opener muscle of the spiny lobsters, Panulirus interruptus and P. argus. 2 GABA-evoked responses were insensitive to picrotoxin at concentrations as high as 5 x 10-5 M. Some blockade by picrotoxin was observed at higher concentrations. 3 In normal physiological saline, the reversal potential of the Panulirus GABA-induced response was near the resting potential. The reversal potential was unaffected by reductions in sodium and calcium. Reduction of chloride by 50% resulted in a greater than 10 mV shift in the reversal potential of the GABA-induced response. 4 Muscimol was able to mimic the action of GABA while baclofen was without effect. Bicuculline was a weak blocker.5 Avermectin Bla irreversibly increased the chloride permeability of the gm6b membrane. This conductance increase was blocked by picrotoxin over a range of concentrations similar to those required for blockade of the GABA-induced response. 6 GABA-induced responses of the gm6b muscle of Homarus americanus were blocked almost completely by picrotoxin 10-6 M.7 Sensitivity to picrotoxin is not invariably associated with GABA-activated chloride-mediated conductance increases. It is suggested that alteration in the binding-site for picrotoxin on the GABAactivated chloride-ion channel does not change other functional characteristics of the GABA-induced response.

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The pharmacological properties of some crustacean neuronal acetylcholine, gamma‐aminobutyric acid, and L‐glutamate responses.

Cited by 166 publications

References 38 publications

Comparison of the action of baclofen with gamma‐aminobutyric acid on rat hippocampal pyramidal cells in vitro.

Comparison of the action of baclofen with gamma‐aminobutyric acid on rat hippocampal pyramidal cells in vitro.

Synaptic Dynamics Do Not Determine Proper Phase of Activity in a Central Pattern Generator

A GABA‐activated chloride‐conductance not blocked by picrotoxin on spiny lobster neuromuscular preparations

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