Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Ionic and pharmacological properties of reciprocal inhibition in Xenopus embryo motoneurones.
Soffe SR
.
???displayArticle.abstract???
1. Properties of rhythmic, compound mid-cycle inhibitory post-synaptic potentials (i.p.s.p.s), which constitute one of the three main synaptic drives to motoneurones during fictive swimming in Xenopus embryos, have been examined using ionic and pharmacological manipulation. 2. Mid-cycle i.p.s.p.s are Cl- dependent. They are reversed by intracellular Cl- injection and attenuated by lowered extracellular Cl- concentration. 3. In response to bath application of 100 microM-glycine or 100 microM-gamma-aminobutyric acid (GABA), motoneurones show a decrease in cell input resistance of 24 +/- 2.9 M omega (mean +/- S.E. of mean) or 16 +/- 3.7% and 26 +/- 6.0 M omega or 14 +/- 2.0% respectively. This is associated with a weak hyperpolarization or depolarization of 0 +/- 1.5 mV and -3 +/- 1.4 mV respectively. Both responses can be made strongly depolarizing by intracellular Cl- injection. 4. The response to glycine is blocked by 1 microM-strychnine but is largely unaffected by bicuculline below 50 microM. The response to GABA is largely blocked by 10 microM-bicuculline but is unaffected by 1 microM-strychnine. Both strychnine and bicuculline are therefore specific antagonists in the amphibian embryo preparation. Glycine and GABA are both partially antagonized by 10 microM-picrotoxin. 5. Mid-cycle i.p.s.p.s recorded in motoneurones during fictive swimming are reduced in amplitude by 0.5-1 microM-strychnine but are largely unaffected by 40 microM-bicuculline. In embryos immobilized by ventral root transection, 100 microM-tubocurarine, a likely GABA antagonist in the embryo, has no effect on mid-cycle inhibition. Glycine is suggested to be the probable transmitter released by commissural interneurones and mediating mid-cycle inhibition during fictive swimming, acting to increase conductance of Cl-.
Alger,
Pharmacological evidence for two kinds of GABA receptor on rat hippocampal pyramidal cells studied in vitro.
1982, Pubmed
Alger,
Pharmacological evidence for two kinds of GABA receptor on rat hippocampal pyramidal cells studied in vitro.
1982,
Pubmed
Bixby,
The appearance and development of chemosensitivity in Rohon-Beard neurones of the Xenopus spinal cord.
1982,
Pubmed
,
Xenbase
Bixby,
The appearance and development of neurotransmitter sensitivity in Xenopus embryonic spinal neurones in vitro.
1984,
Pubmed
,
Xenbase
COOMBS,
The specific ionic conductances and the ionic movements across the motoneuronal membrane that produce the inhibitory post-synaptic potential.
1955,
Pubmed
Curtis,
The hyperpolarization of spinal motoneurones by glycine and related amino acids.
1968,
Pubmed
Dale,
Excitatory amino acid receptors in Xenopus embryo spinal cord and their role in the activation of swimming.
1984,
Pubmed
,
Xenbase
Dale,
Dual-component amino-acid-mediated synaptic potentials: excitatory drive for swimming in Xenopus embryos.
1985,
Pubmed
,
Xenbase
Dale,
Reciprocal inhibitory interneurones in the Xenopus embryo spinal cord.
1985,
Pubmed
,
Xenbase
Gold,
Analysis of glycine-activated inhibitory post-synaptic channels in brain-stem neurones of the lamprey.
1983,
Pubmed
Homma,
Conductance increases produced by glycine and gamma-aminobutyric acid in lamprey interneurones.
1978,
Pubmed
Lamborghini,
Development of a high-affinity GABA uptake system in embryonic amphibian spinal neurons.
1985,
Pubmed
,
Xenbase
Pellegrino,
Distribution of receptors for acetylcholine and 5-hydroxytryptamine on identified leech neurones growing in culture.
1984,
Pubmed
Perret,
Centrally generated pattern of motoneuron activity during locomotion in the cat.
1983,
Pubmed
Roberts,
Initiation and control of swimming in amphibian embryos.
1983,
Pubmed
,
Xenbase
Roberts,
Synaptic potentials in motoneurons during fictive swimming in spinal Xenopus embryos.
1985,
Pubmed
,
Xenbase
Roberts,
The neuroanatomy of an amphibian embryo spinal cord.
1982,
Pubmed
,
Xenbase
Roberts,
Intracellular recordings from spinal neurons during 'swimming' in paralysed amphibian embryos.
1982,
Pubmed
,
Xenbase
Russell,
On the control of myotomal motoneurones during "fictive swimming" in the lamprey spinal cord in vitro.
1983,
Pubmed
Soffe,
Activity of myotomal motoneurons during fictive swimming in frog embryos.
1982,
Pubmed
,
Xenbase
Soffe,
Tonic and phasic synaptic input to spinal cord motoneurons during fictive locomotion in frog embryos.
1982,
Pubmed
,
Xenbase
Soffe,
Activity of commissural interneurons in spinal cord of Xenopus embryos.
1984,
Pubmed
,
Xenbase
