We have located links that may give you full text access.
Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Pre- and postsynaptic contribution of GABAC receptors to GABAergic synaptic transmission in rat collicular slices and cultures.
European Journal of Neuroscience 2003 August
The mammalian superior colliculus (SC) is reported to contain gamma-aminobutyric acid (GABA)C receptors (GABACRs) at high concentration. However, their role in GABAergic synaptic transmission is not yet known. The aim of the present study was: (i) to clarify whether GABACRs are activated by endogenous GABA; and (ii), to determine whether GABACRs play a role in inhibitory synaptic transmission. Experiments were performed on acute horizontal slices from the postnatal rat SC or on collicular neurons in dissociated cell culture. In both preparations, bicuculline-resistant current responses to exogenous GABA and currents elicited by cis-4-aminocrotonic acid (CACA) were blocked by (1,2,5,6-tetrahydropyridine-4-yl) methylphosphinic acid (TPMPA), a GABACR antagonist. The CACA-induced currents exhibited a linear current-voltage relationship and reversed at the Cl- equilibrium potential. These results indicate that functional GABACRs are present in the somato-dendritic membrane of collicular neurons. Miniature inhibitory postsynaptic currents (mIPSCs) were recorded using the whole-cell patch clamp technique. TPMPA significantly decreased mIPSC amplitudes in slices, but not in cultured neurons. As TPMPA decreased also the coefficient of variation of mIPSCs, we suggest that somatodendritic GABACRs are located extrasynaptically but can be involved in the generation of IPSCs if GABA diffusion is constrained. In cultures, individual connections were activated by focal electrical stimulation of single neurons, and evoked inhibitory postsynaptic currents (eIPSCs) were recorded. Paired-pulse stimulation revealed that TPMPA significantly decreased the paired-pulse ratio at short (50 ms) interstimulus intervals, and this effect was inversely dependent on the amplitude of the first eIPSC. We conclude that presynaptic GABACRs are activated by endogenous GABA and can alleviate the short-term depression resulting from a preceding episode of GABA release. Thus, in GABAergic synapses of the SC GABACRs are involved in pre- and postsynaptic functions and may therefore contribute to the activity-dependent adjustment of GABAergic inhibition.
Full text links
Related Resources
Trending Papers
Challenges in Septic Shock: From New Hemodynamics to Blood Purification Therapies.Journal of Personalized Medicine 2024 Februrary 4
Molecular Targets of Novel Therapeutics for Diabetic Kidney Disease: A New Era of Nephroprotection.International Journal of Molecular Sciences 2024 April 4
The 'Ten Commandments' for the 2023 European Society of Cardiology guidelines for the management of endocarditis.European Heart Journal 2024 April 18
A Guide to the Use of Vasopressors and Inotropes for Patients in Shock.Journal of Intensive Care Medicine 2024 April 14
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app