Synaptic interactions between cholinergic and GABAaergic systems of the hippocampus

Gamma-aminobutyric acid (GABA) and acetylcholine (ACh) are important regulators of hippocampal function. The hippocampus is governed by a diverse population of GABAergic local circuit neurones (interneurones) and moreover, receives a dual cholinergic and GABAergic input from the medial septal nucleus (MSN). This thesis describes electrophysiological, pharmacological and neuroanatomical approaches in rodent brain slice preparations to investigate the interaction between these cholinergic and GABAergic systems of the mammalian hippocampus. Intracellular and patch clamp recordings were made from hippocampal pyramidal neurones in hippocampal and septo-hippocampal slice preparations. In the presence of ionotrophic glutamate and GABA receptor antagonists, electrical stimulation of afferent fibres within either the stratum oriens or MSN evoked an isolated slow excitatory postsynaptic potential (EPSP), with mean peak amplitudes of 6.109+/-0.54mV and 8.975+/-1.123mV and peak latencies of 10.14+/-2.743s and 10.264+/-0.95s respectively, in Cal pyramidal neurones. These evoked slow depolarising synaptic responses were suppressed by the selective muscarinic acetylcholine receptor (mAChR) antagonist atropine (5muM) suggesting that they were mediated via activation of mAChRs. In order to investigate whether GABAergic interneurones of the hippocampus are modulated by this cholinergic input, similar experiments were carried out in which whole-cell current clamp recordings were made from hippocampal intemeurones located within the stratum oriens and stratum radiatum of area CA1. (Abstract shortened by ProQuest.)

Writing between the lines Michel Tournier and the end(s) of interpretation

SIGLEAvailable from British Library Document Supply Centre-DSC:D199099 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The International Stripa Project: Technology transfer from cooperation in scientific and technological research on nuclear waste disposal

The Nuclear Energy Agency of the organization for Economic Cooperation and Development (OECD/NEA) sponsors the International Stripa Project. The objectives of the Stripa Project are to develop techniques for characterizing sites located deep in rock formations that are potentially suitable for the geologic disposal of high-level radioactive wastes and to evaluate particular engineering design considerations that could enhance the long-term safety of a high-level radioactive waste repository in a geologic medium. The purpose of this paper is to briefly summarize the research conducted at Stripa and discuss the ways in which the technology developed for the Stripa Project has been and will be transfered to the United States Civilian Radioactive Waste Management Program`s Yucca Mountain Project. 3 refs., 2 figs