Influence of extracellular and intracellular pH on GABA-gated chloride conductance in crayfish muscle fibres.
The effect of intracellular and extracellular pH on GABA-gated Cl- conductance was studied using H(+)-selective microelectrodes and a three-microelectrode voltage clamp in crayfish leg opener muscle fibres in bicarbonate-free solutions. Experimental variation of intracellular pH in the range 6.4-8.0...
| Príomhchruthaitheoirí: | , , , |
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| Formáid: | Journal article |
| Teanga: | English |
| Foilsithe / Cruthaithe: |
1992
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| _version_ | 1826302442168385536 |
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| author | Pasternack, M Bountra, C Voipio, J Kaila, K |
| author_facet | Pasternack, M Bountra, C Voipio, J Kaila, K |
| author_sort | Pasternack, M |
| collection | OXFORD |
| description | The effect of intracellular and extracellular pH on GABA-gated Cl- conductance was studied using H(+)-selective microelectrodes and a three-microelectrode voltage clamp in crayfish leg opener muscle fibres in bicarbonate-free solutions. Experimental variation of intracellular pH in the range 6.4-8.0 did not affect the GABA-gated conductance. In contrast to this, the GABA-gated conductance was sensitive to changes in external pH. Raising the external pH from 7.4 to 8.4 decreased the GABA-gated peak conductance observed immediately following application of GABA by 30%, and a change from 7.4 to 6.4 produced an increase of 26%. The effect of extracellular pH on the GABA-gated peak conductance was approximately linear in the pH range 6.4-8.9. A slight decrease in the slope of the pH-conductance relationship was evident in the pH range 5.4-6.4. The desensitization of the GABA-gated conductance was also affected by external pH. At pH 6.9 the conductance produced by 1 mM GABA showed a desensitization of about 15%, and at pH 8.9 this value was 34%. Raising the external pH in the presence of GABA decreased the GABA-gated peak conductance and increased the fractional desensitization, while lowering the external pH produced opposite effects, and was capable of repriming the conductance from a desensitized state to the non-desensitized state. The above results show that the GABA-gated conductance is sensitive to changes in external pH in the physiological range, and suggest that pH-dependent changes in the postsynaptic efficacy of GABA-mediated inhibition may contribute to H+ modulation of neuronal excitability. |
| first_indexed | 2024-03-07T05:47:36Z |
| format | Journal article |
| id | oxford-uuid:e7be1d4c-7b9f-4b4d-a9c3-fb60fcee1e05 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T05:47:36Z |
| publishDate | 1992 |
| record_format | dspace |
| spelling | oxford-uuid:e7be1d4c-7b9f-4b4d-a9c3-fb60fcee1e052022-03-27T10:41:12ZInfluence of extracellular and intracellular pH on GABA-gated chloride conductance in crayfish muscle fibres.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:e7be1d4c-7b9f-4b4d-a9c3-fb60fcee1e05EnglishSymplectic Elements at Oxford1992Pasternack, MBountra, CVoipio, JKaila, KThe effect of intracellular and extracellular pH on GABA-gated Cl- conductance was studied using H(+)-selective microelectrodes and a three-microelectrode voltage clamp in crayfish leg opener muscle fibres in bicarbonate-free solutions. Experimental variation of intracellular pH in the range 6.4-8.0 did not affect the GABA-gated conductance. In contrast to this, the GABA-gated conductance was sensitive to changes in external pH. Raising the external pH from 7.4 to 8.4 decreased the GABA-gated peak conductance observed immediately following application of GABA by 30%, and a change from 7.4 to 6.4 produced an increase of 26%. The effect of extracellular pH on the GABA-gated peak conductance was approximately linear in the pH range 6.4-8.9. A slight decrease in the slope of the pH-conductance relationship was evident in the pH range 5.4-6.4. The desensitization of the GABA-gated conductance was also affected by external pH. At pH 6.9 the conductance produced by 1 mM GABA showed a desensitization of about 15%, and at pH 8.9 this value was 34%. Raising the external pH in the presence of GABA decreased the GABA-gated peak conductance and increased the fractional desensitization, while lowering the external pH produced opposite effects, and was capable of repriming the conductance from a desensitized state to the non-desensitized state. The above results show that the GABA-gated conductance is sensitive to changes in external pH in the physiological range, and suggest that pH-dependent changes in the postsynaptic efficacy of GABA-mediated inhibition may contribute to H+ modulation of neuronal excitability. |
| spellingShingle | Pasternack, M Bountra, C Voipio, J Kaila, K Influence of extracellular and intracellular pH on GABA-gated chloride conductance in crayfish muscle fibres. |
| title | Influence of extracellular and intracellular pH on GABA-gated chloride conductance in crayfish muscle fibres. |
| title_full | Influence of extracellular and intracellular pH on GABA-gated chloride conductance in crayfish muscle fibres. |
| title_fullStr | Influence of extracellular and intracellular pH on GABA-gated chloride conductance in crayfish muscle fibres. |
| title_full_unstemmed | Influence of extracellular and intracellular pH on GABA-gated chloride conductance in crayfish muscle fibres. |
| title_short | Influence of extracellular and intracellular pH on GABA-gated chloride conductance in crayfish muscle fibres. |
| title_sort | influence of extracellular and intracellular ph on gaba gated chloride conductance in crayfish muscle fibres |
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