caa a22 4500 60620329X CHVBK 20210128100957.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s00429-013-0692-6 doi (NATIONALLICENCE)springer-10.1007/s00429-013-0692-6 Quantitative ultrastructural analysis of basket and axo-axonic cell terminals in the mouse hippocampus [Elektronische Daten] [Virág Takács, András Szőnyi, Tamás Freund, Gábor Nyiri, Attila Gulyás] Three functionally different populations of perisomatic interneurons establish GABAergic synapses on hippocampal pyramidal cells: parvalbumin (PV)-containing basket cells, type 1 cannabinoid receptor (CB1)-positive basket cells both of which target somata, and PV-positive axo-axonic cells that innervate axon initial segments. Using electron microscopic reconstructions, we estimated that a pyramidal cell body receives synapses from about 60 and 140 synaptic terminals in the CA1 and CA3 area, respectively. About 60% of these terminals were PV positive, whereas 35-40% of them were CB1 positive. Only about 1% (CA1) and 4% (CA3) of the somatic boutons were negative for both markers. Using fluorescent labeling, we showed that most of the CB1-positive terminals expressed vesicular glutamate transporter 3. Reconstruction of somatic boutons revealed that although their volumes are similar, CB1-positive boutons are more flat and the total volume of their mitochondria was smaller than that of PV-positive boutons. Both types of boutons contain dense-core vesicles and frequently formed multiple release sites on their targets and innervated an additional soma or dendrite as well. PV-positive boutons possessed small, macular synapses; whereas the total synaptic area of CB1-positive boutons was larger and formed multiple irregular-shaped synapses. Axo-axonic boutons were smaller than somatic boutons, had only one synapse and their ultrastructural parameters were closer to those of PV-positive somatic boutons. Our results represent the first quantitative measurement—using a highly reliable method—of the contribution of different cell types to the perisomatic innervation of pyramidal neurons, and may help to explain functional differences in their output properties. Springer-Verlag Berlin Heidelberg, 2014 Inhibitory neurons nationallicence Synaptic convergence nationallicence Active zone nationallicence Three-dimensional reconstruction nationallicence Immunogold nationallicence Takács Virág Laboratory of Cerebral Cortex Research, Department of Cellular and Network Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary aut Szőnyi András Laboratory of Cerebral Cortex Research, Department of Cellular and Network Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary aut Freund Tamás Laboratory of Cerebral Cortex Research, Department of Cellular and Network Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary aut Nyiri Gábor Laboratory of Cerebral Cortex Research, Department of Cellular and Network Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary aut Gulyás Attila Laboratory of Cerebral Cortex Research, Department of Cellular and Network Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary aut Brain Structure and Function Springer Berlin Heidelberg 220/2(2015-03-01), 919-940 1863-2653 220:2<919 2015 220 429 https://doi.org/10.1007/s00429-013-0692-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00429-013-0692-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Takács Virág Laboratory of Cerebral Cortex Research, Department of Cellular and Network Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary aut NATIONALLICENCE 700 1- Szőnyi András Laboratory of Cerebral Cortex Research, Department of Cellular and Network Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary aut NATIONALLICENCE 700 1- Freund Tamás Laboratory of Cerebral Cortex Research, Department of Cellular and Network Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary aut NATIONALLICENCE 700 1- Nyiri Gábor Laboratory of Cerebral Cortex Research, Department of Cellular and Network Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary aut NATIONALLICENCE 700 1- Gulyás Attila Laboratory of Cerebral Cortex Research, Department of Cellular and Network Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary aut NATIONALLICENCE 773 0- Brain Structure and Function Springer Berlin Heidelberg 220/2(2015-03-01), 919-940 1863-2653 220:2<919 2015 220 429