UCL logo

UCL Discovery

UCL home » Library Services » Electronic resources » UCL Discovery

Presynaptic GABAA receptors enhance glutamatergic transmission and facilitate LTP induction at hippocampal mossy fibre synapses

Ruiz, AJ; Campanac, E; Scott, R; Rusakov, D; Kullmann, D; (2010) Presynaptic GABAA receptors enhance glutamatergic transmission and facilitate LTP induction at hippocampal mossy fibre synapses. Presented at: 7th FENS Forum of European Neuroscience, RAI Convention Centre, Amsterdam, The Netherlands.

Full text not available from this repository.

Abstract

Presynaptic GABAA receptors occur at hippocampal mossy fibres where they modulate axonal excitability and action potential-dependent Ca2+ transients in individual varicosities. How they modulate neurotransmitter release to postsynaptic targets in CA3 is however poorly understood. We obtained direct patch-clamp recordings from mossy fibre boutons, CA3 pyramidal neurons and interneurones held in voltage-clamp in rat hippocampal slices (postnatal days 21 to 35). We also measured presynaptic action potential-dependent Ca2+ transients in large mossy fibre boutons using 2-photon laser scanning microscopy. We showed that allosteric modulators selective for high-affinity delta-subunit-containing GABAA receptors depolarize mossy fibre boutons, enhance action potential-dependent Ca2+ transients, and facilitate glutamatergic transmission to CA3 pyramidal neurons and stratum lucidum interneurones. Conversely, blocking GABAA receptors with the competitive receptor antagonist gabazine hyperpolarized mossy fibre boutons, increased their input resistance, decreased spike width, and attenuated action potential-dependent presynaptic Ca2+ transients. These results indicate that a subset of presynaptic GABA receptors is tonically active in the absence of added GABA and in conditions where uptake mechanisms are functional. Blocking GABAA receptors also impaired the induction of long-term potentiation at mossy fibre - CA3 synapses, presumably via a presynaptic action. Thus, presynaptic GABAA receptors facilitate synaptic transmission to the hippocampus both directly and by enhancing LTP.

Type: Conference item (UNSPECIFIED)
Title: Presynaptic GABAA receptors enhance glutamatergic transmission and facilitate LTP induction at hippocampal mossy fibre synapses
Event: 7th FENS Forum of European Neuroscience
Location: RAI Convention Centre, Amsterdam, The Netherlands
UCL classification: UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology > Clinical and Experimental Epilepsy
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > UCL School of Pharmacy
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > UCL School of Pharmacy > Pharmacology
URI: http://discovery.ucl.ac.uk/id/eprint/1380436
Downloads since deposit
0Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item