Gamma frequency oscillations in cortical regions can be recorded during cognitive processes, including attention or memory tasks. These are generated locally as a result of reciprocal interactions between excitatory pyramidal cells and perisomatic inhibitory interneurons. Here, we examined the contribution three interneuron types—the parvalbumin-containing fast-spiking basket (FSBCs) axo-axonic (AACs), well cholecystokinin-containing regular-spiking (RSBCs) to cholinergically induced...

Cortical information processing is under state-dependent control of subcortical neuromodulatory systems. Although this modulatory effect thought to be mediated mainly by slow nonsynaptic metabotropic receptors, other mechanisms, such as direct synaptic transmission, are possible. Yet, it currently unknown if any form exists. Here, we present evidence a strong, spatiotemporally precise excitatory input from an ascending center. Selective stimulation serotonergic median raphe neurons produced...

Classic theories link cognitive abilities to synaptic properties and human-specific biophysical features of synapses might contribute the unparalleled performance human cerebral cortex. Paired recordings multiple probability fluctuation analysis revealed similar quantal sizes, but 4-times more functional release sites in pyramidal cell fast-spiking interneuron connections compared rats. These were mediated on average by three contacts both species. Each presynaptic active zone (AZ) contains...

Abstract Perisomatic inhibition originates from three types of GABAergic interneurons in cortical structures, including parvalbumin‐containing fast‐spiking basket cells (FSBCs) and axo‐axonic (AACs), as well cholecystokinin‐expressing regular‐spiking (RSBCs). These may have significant impact various cognitive processes, are subjects cholinergic modulation. However, it is largely unknown how receptor activation modulates the function perisomatic inhibitory cells. Therefore, we performed...

CB₁ cannabinoid receptors (CB₁) are located at axon terminals and effectively control synaptic communication thereby circuit operation widespread in the CNS. Although it is partially uncovered how activation leads to reduction of excitation, mechanisms decrease GABA release upon these remain elusive. To determine underlying suppression transmission by GABAergic synapses, we recorded unitary IPSCs (uIPSCs) cholecystokinin-expressing interneuron-pyramidal cell connections...

A stunning example of synaptic diversity is the postsynaptic target cell-type-dependent difference in efficacy cortical networks. Here, we show that CA1 pyramidal cell (PC) to fast spiking interneuron (FSIN) connections have 10-fold larger release probability (Pv) than those on oriens lacunosum-moleculare (O-LM) interneurons. Freeze-fracture immunolabeling revealed different nano-topologies and coupling distances between Ca2+ channels sites (RSs) are not responsible for distinct Pv. Although...

Short-term synaptic plasticity changes the reliability of transmission during repetitive activation and allows different neuronal ensembles to encode distinct features action potential trains. Identifying mechanisms locus expression such is essential for understanding information processing. To determine quantal parameters alterations short-term cortical glutamatergic synapses, EPSCs were evoked in hippocampal oriens-alveus interneurons by CA1 pyramidal cells. The robust facilitation this...

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...

The molecular mechanisms underlying the diversity of cortical glutamatergic synapses are still incompletely understood. Here, we tested hypothesis that presynaptic active zones (AZs) constructed from molecularly uniform, independent release sites (RSs), number which scales linearly with AZ size. Paired recordings between hippocampal CA1 pyramidal cells and fast-spiking interneurons in acute slices adult mice followed by quantal analysis demonstrate large variability RSs ( N ) at these...

The amount of neurotransmitter released after the arrival an action potential affects strength and trial-to-trial variability postsynaptic responses. Most studies examining dependence synaptic concentration on release probability ( P r ) have focused glutamatergic synapses. Here we asked whether univesicular or multivesicular characterizes transmission at hippocampal GABAergic We used multiple functional analysis to derive quantal parameters inhibitory connections between cannabinoid...

Potassium channels comprise the most diverse family of ion channels. In nerve cells, their critical roles in synaptic integration and output generation have been demonstrated. Here, we provide evidence for a distribution that predicts novel role K + CNS. Our experiments revealed highly selective clustering Kv4.3 A-type channel subunits at specialized junctions between climbing fibers cerebellar GABAergic interneurons. High-resolution ultrastructural immunohistochemical demonstrated these are...

Abstract The release of GABA from cholecystokinin-containing interneurons is modulated by type-1 cannabinoid receptors (CB 1 ). Here we tested the hypothesis that strength CB -mediated modulation related to content axon terminals. Basket cell boutons have on average 78% higher than those dendritic-layer-innervating (DLI) cells, a consequence larger bouton surface and density. antagonist AM251 caused 54% increase in action potential-evoked [Ca 2+ ] basket but not DLI cells. However, effect...

CB(1) cannabinoid receptor (CB(1)R) activation by exogenous ligands can impair memory processes, which critically depend on synchronous neuronal activities that are temporarily structured oscillations. In this study, we aimed to reveal the mechanisms underlying cannabinoid-induced decrease in gamma We first verified cannabinoids (CP55,940 and WIN55,212-2) readily suppressed carbachol-induced oscillations CA3 region of hippocampal slices via CB(1)Rs. The peak power was accompanied reduced...

Elucidating the molecular mechanisms underlying functional diversity of synapses requires a high-resolution, sensitive, diffusion-free, quantitative localization method that allows determination many proteins in functionally characterized individual synapses. Array tomography permits analysis single but has limited sensitivity, and its application to is challenging. Here, we aim overcome these limitations by searching parameter space different fixation, resin, embedding, etching, retrieval,...

In many brain regions, hyperpolarization-activated cationic currents (Ih) are involved in the generation of rhythmic activities, but role Ih olfactory oscillations remains unclear. Knowledge cellular and subcellular distributions cyclic nucleotide-gated channel (HCN) subunits is necessary for understanding network activities. Using light microscopic immunocytochemistry, we demonstrate strong HCN1 labelling glomerular layer moderate staining granule cell, internal external plexiform layers...

Abstract Theoretical and functional studies predicted a highly non‐uniform distribution of voltage‐gated ion channels on the neuronal surface. This was confirmed by recent immunolocalization experiments for Na + , Ca 2+ hyperpolarization activated mixed cation K channels. These also indicated that some were clustered in synaptic or non‐synaptic membrane specializations. Here we analysed subcellular Kv4.2 Kv4.3 subunits rat main olfactory bulb at high resolution to address whether clustering...

Selective distribution of proteins in presynaptic active zones (AZs) is a prerequisite for generating postsynaptic target cell type-specific differences vesicle release probability (Pv) and short-term plasticity, characteristic feature cortical pyramidal cells (PCs). In the hippocampus rodents, somatostatin mGluR1α expressing interneurons (mGluR1α+ INs) receive small, facilitating excitatory currents (EPSCs) from PCs express Elfn1 that trans-synaptically recruits mGluR7 into AZ PC axons....

Traditionally, Echinacea preparations are used as antiinflammatory agents and immune‐enhancers. In addition to these effects, their anxiolytic potency has been recognized recently in laboratory tests. Our aim this study was uncover the potential effects of an preparation on neuronal operations hippocampus, a brain region that is involved anxiety anxiety‐related behaviors. Using vitro electrophysiological techniques, we observed excitatory synaptic transmission hippocampal slices...

Stereological methods for estimating the 3D particle size and density from 2D projections are essential to many research fields. These are, however, prone errors arising undetected profiles due sectioning limited resolution, known as ‘lost caps’. A potential solution developed by Keiding, Jensen, Ranek in 1972, which we refer Keiding model, accounts lost caps quantifying smallest detectable profile terms of its limiting ‘cap angle’ (ϕ), a size-independent measure particle’s distance section...