--- _id: '2629' abstract: - lang: eng text: The release of neurotransmitters is modulated by presynaptic metabotropic glutamate receptors (mGluRs), which show a highly selective expression and subcellular location in glutamatergic terminals in the hippocampus. Using immunocytochemistry, we investigated whether one of the receptors, mGluR7, whose level of expression is governed by the postsynaptic target, was present in GABAergic terminals and whether such terminals targeted particular cells. A total of 165 interneuron dendritic profiles receiving 466 synapses (82% mGluR7a-positive) were analysed. The presynaptic active zones of most GAD-(77%) or GABA-positive (94%) synaptic boutons on interneurons innervated by mGluR7a-enriched glutamatergic terminals (mGluR7a-decorated) were immunopositive for mGluR7a. GABAergic terminals on pyramidal cells and most other interneurons in str. oriens were mGluR7a-immunonegative. The mGluR7a-decorated cells were mostly somatostatin- and mGluR1α-immunopositive neurons in str. oriens and the alveus. Their GABAergic input mainly originated from VIP-positive terminals, 90% of which expressed high levels of mGluR7a in the presynaptic active zone. Parvalbumin-positive synaptic terminals were rare on mGluR7a-decorated cells, but on these neurons 73% of them were mGluR7a-immunopositive. Some type II synapses innervating interneurons were immunopositive for mGluR7b, as were some type I synapses. Because not all target cells of VIP-positive neurons are known it has not been possible to determine whether mGluR7 is expressed in a target-cell-specific manner in the terminals of single GABAergic cells. The activation of mGluR7 may decrease GABA release to mGluR7-decorated cells at times of high pyramidal cell activity, which elevates extracellular glutamate levels. Alternatively, the presynaptic receptor may be activated by as yet unidentified endogenous ligands released by the GABAergic terminals or the postsynaptic dendrites. author: - first_name: Péter full_name: Somogyi, Péter last_name: Somogyi - first_name: Yannis full_name: Dalezios, Yannis last_name: Dalezios - first_name: Rafael full_name: Luján, Rafael last_name: Luján - first_name: John full_name: Roberts, John D last_name: Roberts - first_name: Masahiko full_name: Watanabe, Masahiko last_name: Watanabe - first_name: Ryuichi full_name: Ryuichi Shigemoto id: 499F3ABC-F248-11E8-B48F-1D18A9856A87 last_name: Shigemoto orcid: 0000-0001-8761-9444 citation: ama: Somogyi P, Dalezios Y, Luján R, Roberts J, Watanabe M, Shigemoto R. High level of mGluR7 in the presynaptic active zones of select populations of GABAergic terminals innervating interneurons in the rat hippocampus. European Journal of Neuroscience. 2003;17(12):2503-2520. doi:10.1046/j.1460-9568.2003.02697.x apa: Somogyi, P., Dalezios, Y., Luján, R., Roberts, J., Watanabe, M., & Shigemoto, R. (2003). High level of mGluR7 in the presynaptic active zones of select populations of GABAergic terminals innervating interneurons in the rat hippocampus. European Journal of Neuroscience. Wiley-Blackwell. https://doi.org/10.1046/j.1460-9568.2003.02697.x chicago: Somogyi, Péter, Yannis Dalezios, Rafael Luján, John Roberts, Masahiko Watanabe, and Ryuichi Shigemoto. “High Level of MGluR7 in the Presynaptic Active Zones of Select Populations of GABAergic Terminals Innervating Interneurons in the Rat Hippocampus.” European Journal of Neuroscience. Wiley-Blackwell, 2003. https://doi.org/10.1046/j.1460-9568.2003.02697.x. ieee: P. Somogyi, Y. Dalezios, R. Luján, J. Roberts, M. Watanabe, and R. Shigemoto, “High level of mGluR7 in the presynaptic active zones of select populations of GABAergic terminals innervating interneurons in the rat hippocampus,” European Journal of Neuroscience, vol. 17, no. 12. Wiley-Blackwell, pp. 2503–2520, 2003. ista: Somogyi P, Dalezios Y, Luján R, Roberts J, Watanabe M, Shigemoto R. 2003. High level of mGluR7 in the presynaptic active zones of select populations of GABAergic terminals innervating interneurons in the rat hippocampus. European Journal of Neuroscience. 17(12), 2503–2520. mla: Somogyi, Péter, et al. “High Level of MGluR7 in the Presynaptic Active Zones of Select Populations of GABAergic Terminals Innervating Interneurons in the Rat Hippocampus.” European Journal of Neuroscience, vol. 17, no. 12, Wiley-Blackwell, 2003, pp. 2503–20, doi:10.1046/j.1460-9568.2003.02697.x. short: P. Somogyi, Y. Dalezios, R. Luján, J. Roberts, M. Watanabe, R. Shigemoto, European Journal of Neuroscience 17 (2003) 2503–2520. date_created: 2018-12-11T11:58:46Z date_published: 2003-06-01T00:00:00Z date_updated: 2021-01-12T06:58:41Z day: '01' doi: 10.1046/j.1460-9568.2003.02697.x extern: 1 intvolume: ' 17' issue: '12' month: '06' page: 2503 - 2520 publication: European Journal of Neuroscience publication_status: published publisher: Wiley-Blackwell publist_id: '4269' quality_controlled: 0 status: public title: High level of mGluR7 in the presynaptic active zones of select populations of GABAergic terminals innervating interneurons in the rat hippocampus type: journal_article volume: 17 year: '2003' ...