Target Cell Type-Dependent Differences in Ca2+Channel Function Underlie Distinct Release Probabilities at Hippocampal Glutamatergic Terminals

• DOI: 10.1523/jneurosci.2024-16.2017
• Publication Date: 2017-01-24T02:50:40Z
• Authors: Tímea Éltes; Tekla Kirizs; Zoltan Nusser; Noemi Holderith
• Keywords: Pyramidal cell

Target cell type-dependent differences in presynaptic release probability ( P r ) and short-term plasticity are intriguing features of cortical microcircuits that increase the computational power neuronal networks. Here, we tested hypothesis different voltage-gated Ca 2+ channel densities active zones (AZs) underlie values. Two-photon imaging, triple immunofluorescent labeling, 3D electron microscopic (EM) reconstruction rat CA3 pyramidal axon terminals revealed ∼1.7–1.9 times higher inflow per AZ area high boutons synapsing onto parvalbumin-positive interneurons (INs) than low mGluR1α-positive INs. EM replica immunogold however, demonstrated only 1.15 larger Cav2.1 Cav2.2 subunit AZs. Our results indicate target type-specific modulation function or composition as possible mechanisms underlying functional differences. In addition, synapses also characterized by a density docked vesicles, suggesting concerted action these underlies SIGNIFICANCE STATEMENT variability properties is an feature synapses. When single establishes synapse somatostatin-expressing interneuron (IN), releases glutamate with probability, whereas next bouton same has when its postsynaptic parvalbumin-expressing IN. used combined molecular, anatomical approaches to investigate experiments implied approximately twofold boutons, freeze–fracture immunolocalization 15% difference densities. point toward regulation mechanism.