scholarly journals Selective Cholinergic Modulation of Cortical GABAergic Cell Subtypes

1997 ◽  
Vol 78 (3) ◽  
pp. 1743-1747 ◽  
Author(s):  
Yasuo Kawaguchi
Keyword(s):  
Frontal Cortex ◽  
Calcium Binding ◽  
Pyramidal Cells ◽  
Inhibitory Interneurons ◽  
Muscarinic Agonists ◽  
Cholinergic Modulation ◽  
Morphological Criteria ◽  
Cell Recording ◽  
Fast Spiking

Kawaguchi, Yasuo. Selective cholinergic modulation of cortical GABAergic cell subtypes. J. Neurophysiol. 78: 1743–1747, 1997. Acetylcholine from the basal forebrain and γ-aminobutyric acid (GABA) from intracortical inhibitory interneurons exert strong influence on the cortical activity and may interact with each other. Cholinergic or muscarinic agonists indeed induced GABAergic postsynaptic currents in pyramidal cells by exciting inhibitory interneurons that have recently been classified into several distinct subtypes on the basis of the physiological, chemical, and morphological criteria. Cholinergic effects on GABAergic cell subtypes were investigated of rat frontal cortex by in vitro whole cell recording with intracellular staining in frontal cortex of young rats. GABAergic cell subtypes were identified physiologically by firing responses to depolarizing current pulses and immunohistochemically as containing parvalbumin, somatostatin, vasoactive intestinal polypeptide (VIP), or cholecystokinin (CCK). Carbachol (10 μM) or (+)-muscarine (3 μM) affected the activities of peptide-containing GABAergic cells with regular- or burst-spiking characteristics, but not of GABAergic cells with fast-spiking characteristics containing the calcium-binding protein parvalbumin orGABAergic cells with late-spiking characteristics. Somatostatin- or VIP-immunoreactive cells were depolarized with spike firing. CCK-immunoreactive cells were affected heterogeneously by cholinergic agonists. Larger CCK cells were hyperpolarized, followed by a slow depolarization, whereas smaller CCK cells were only depolarized. These results suggest that the excitability of cortical GABAergic cell subtypes is differentially regulated by acetylcholine. Differences in cholinergic responses suggest a distinct functional role of each GABAergic cell subtype.

Spike Coding in Pyramidal Cells of the Piriform Cortex of Rat

2001 ◽  
Vol 86 (3) ◽  
pp. 1504-1510 ◽  
Author(s):  
Alexander D. Protopapas ◽  
James M. Bower
Keyword(s):  
Cognitive Function ◽  
Piriform Cortex ◽  
Pyramidal Cells ◽  
Spike Trains ◽  
Gamma Range ◽  
Cortical Oscillations ◽  
Cell Recording ◽  
Spike Coding ◽  
Theta Range

The study of cortical oscillations has undergone a renaissance in recent years because of their presumed role in cognitive function. Of particular interest are frequencies in the gamma (30–100 Hz) and theta (3–12 Hz) ranges. In this paper, we use spike coding techniques and in vitro whole cell recording to assess the ability of individual pyramidal cells of the piriform cortex to code inputs occurring in these frequencies. The results suggest that the spike trains of individual neurons are much better at representing frequencies in the theta range than those in the gamma range.

scholarly journals Synchronized gamma-frequency inhibition in neocortex depends on excitatory-inhibitory interactions but not electrical synapses

2016 ◽  
Vol 116 (2) ◽  
pp. 351-368 ◽  
Author(s):  
Garrett T. Neske ◽  
Barry W. Connors
Keyword(s):  
Pyramidal Neurons ◽  
Barrel Cortex ◽  
Pyramidal Cells ◽  
Inhibitory Interneurons ◽  
Electrical Synapses ◽  
Postsynaptic Currents ◽  
Gamma Frequency ◽  
Up States ◽  
Inhibitory Interactions

Synaptic inhibition plays a crucial role in the precise timing of spiking activity in the cerebral cortex. Synchronized, rhythmic inhibitory activity in the gamma (30–80 Hz) range is thought to be especially important for the active, information-processing neocortex, but the circuit mechanisms that give rise to synchronized inhibition are uncertain. In particular, the relative contributions of reciprocal inhibitory connections, excitatory-inhibitory interactions, and electrical synapses to precise spike synchrony among inhibitory interneurons are not well understood. Here we describe experiments on mouse barrel cortex in vitro as it spontaneously generates slow (<1 Hz) oscillations (Up and Down states). During Up states, inhibitory postsynaptic currents (IPSCs) are generated at gamma frequencies and are more synchronized than excitatory postsynaptic currents (EPSCs) among neighboring pyramidal cells. Furthermore, spikes in homotypic pairs of interneurons are more synchronized than in pairs of pyramidal cells. Comparing connexin36 knockout and wild-type animals, we found that electrical synapses make a minimal contribution to synchronized inhibition during Up states. Estimations of the delays between EPSCs and IPSCs in single pyramidal cells showed that excitation often preceded inhibition by a few milliseconds. Finally, tonic optogenetic activation of different interneuron subtypes in the absence of excitation led to only weak synchrony of IPSCs in pairs of pyramidal neurons. Our results suggest that phasic excitatory inputs are indispensable for synchronized spiking in inhibitory interneurons during Up states and that electrical synapses play a minimal role.

scholarly journals Optogenetic inhibition-mediated activity-dependent modification of CA1 pyramidal-interneuron connections during behavior

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Igor Gridchyn ◽  
Philipp Schoenenberger ◽  
Joseph O'Neill ◽  
Jozsef Csicsvari
Keyword(s):  
Firing Rate ◽  
Pyramidal Cell ◽  
Pyramidal Cells ◽  
Inhibitory Interneurons ◽  
Spike Synchrony ◽  
Synaptic Inputs ◽  
Cross Correlations ◽  
Dependent Modification ◽  
Activity Dependent

In vitro work revealed that excitatory synaptic inputs to hippocampal inhibitory interneurons could undergo Hebbian, associative, or non-associative plasticity. Both behavioral and learning-dependent reorganization of these connections has also been demonstrated by measuring spike transmission probabilities in pyramidal cell-interneuron spike cross-correlations that indicate monosynaptic connections. Here we investigated the activity-dependent modification of these connections during exploratory behavior in rats by optogenetically inhibiting pyramidal cell and interneuron subpopulations. Light application and associated firing alteration of pyramidal and interneuron populations led to lasting changes in pyramidal-interneuron connection weights as indicated by spike transmission changes. Spike transmission alterations were predicted by the light-mediated changes in the number of pre- and postsynaptic spike pairing events and by firing rate changes of interneurons but not pyramidal cells. This work demonstrates the presence of activity-dependent associative and non-associative reorganization of pyramidal-interneuron connections triggered by the optogenetic modification of the firing rate and spike synchrony of cells.

GAT-3 Transporters Regulate Inhibition in the Neocortex

2005 ◽  
Vol 94 (6) ◽  
pp. 4533-4537 ◽  
Author(s):  
Gregory A. Kinney
Keyword(s):  
Pyramidal Cells ◽  
Gaba Release ◽  
Inhibitory Interneuron ◽  
Inhibitory Interneurons ◽  
Slice Preparation ◽  
Rat Neocortex ◽  
Ambient Gaba ◽  
Layer V

The role of GAT-3 transporters in regulating GABAA receptor-mediated inhibition was examined in the rat neocortex using an in vitro slice preparation. Pharmacologically isolated GABAA receptor-mediated responses were recorded from layer V neocortical pyramidal cells, and the effects of SNAP-5114, a GAT-3 GABA transporter-selective antagonist, were evaluated. Application of SNAP-5114 resulted in a reversible increase in the amplitude of an evoked GABAA response in most cells examined, although no effect on the decay time was observed. Examination of the spontaneous output of inhibitory interneurons revealed a reversible increase in the frequency and amplitude of spontaneous inhibitory synaptic currents as a consequence of GAT-3 inhibition. This effect of GAT-3 inhibition on spontaneous inhibitory events was action potential-dependent because no such increases were observed when SNAP-5114 was applied in the presence of TTX. These results demonstrate that GAT-3 transporters regulate inhibitory interneuron output in the neocortex. The increase in inhibitory interneuron excitability resulting from application of SNAP-5114 suggests that inhibition of GAT-3 transporter function results in a reduction in ambient GABA levels, possibly by a reduction in carrier-mediated GABA release via the GAT-3 transporter.

Dual role of norepinephrine in the hippocampal CA1 region of the rat: inhibition and disinhibition

1988 ◽  
Vol 66 (6) ◽  
pp. 814-819 ◽  
Author(s):  
Patrick P.-H. Leung ◽  
James J. Miller
Keyword(s):  
Pyramidal Neurons ◽  
Epileptiform Activity ◽  
Pyramidal Cells ◽  
Inhibitory Effect ◽  
Stratum Radiatum ◽  
Inhibitory Interneurons ◽  
Spike Response ◽  
Paired Pulse ◽  
Ca1 Region

Norepinephrine (NE) has been shown to produce either an inhibitory or an excitatory influence on CA1 pyramidal neurons of the hippocampus depending on the dosage. It was suggested that NE, in addition to exerting a direct inhibitory effect on pyramidal cells, may also act upon recurrent inhibitory interneurons to produce a disinhibition of the pyramidal cells. The present study was undertaken to examine the effect of NE on alveus-evoked inhibition, presumably mediated by the basket cell interneurons innervating the pyramidal cells. Experiments were carried out on the in vitro hippocampal slice preparation and inhibition was assessed by the percent reduction of the stratum radiatum evoked population spike response when preceded by a conditioning pulse delivered to the alveus to activate the inhibitory interneurons via the recurrent collaterals of the pyramidal cells. Paired pulse stimulation resulted in inhibition of the stratum radiatum evoked test response with conditioning-test intervals up to 60 ms. NE (50 μM) perfusion resulted in a significant and reversible reduction of the alveus-evoked recurrent inhibition. Intracellular recordings using a similar paired pulse paradigm corroborated the extracellular data well. The possible roles of NE in the physiological functioning and pathophysiology of epileptiform activity of the hippocampus are discussed.

Correlation of physiological subgroupings of nonpyramidal cells with parvalbumin- and calbindinD28k-immunoreactive neurons in layer V of rat frontal cortex

1993 ◽  
Vol 70 (1) ◽  
pp. 387-396 ◽  
Author(s):  
Y. Kawaguchi ◽  
Y. Kubota
Keyword(s):  
Frontal Cortex ◽  
Calcium Binding ◽  
Binding Proteins ◽  
Pyramidal Cells ◽  
Calcium Binding Proteins ◽  
Immunofluorescent Staining ◽  
Repetitive Firing ◽  
Low Threshold ◽  
Layer V ◽  
Layer I

1. To test the hypothesis that physiologically and morphologically different cortical nonpyramidal cells express different calcium-binding proteins, whole-cell current-clamp recording in vitro was combined with intracellular staining and double immunofluorescence in layer V of frontal cortex of rats 16-20 days old. 2. Nonpyramidal cells were first characterized as fast-spiking (FS) or low-threshold spike (LTS) cells, injected with biocytin, and subsequently stained immunohistochemically for parvalbumin and calbindinD28k. 3. FS cells were identified by input resistances < 350 M omega, spike width at half amplitude < 0.8 ms, and virtually no spike frequency adaptation of spike trains by depolarizing pulses. LTS cells were identified by input resistances > 350 M omega, spike width at half amplitude > 0.8 ms, and the discharge of low-threshold spikes from hyperpolarized potentials. Repetitive firing could be induced by a combination of stimulation-induced excitatory postsynaptic potentials with depolarization in FS cells. Repetitive firing was not observed in LTS cells under these conditions. 4. After biocytin injection of layer V cells characterized in this way, subsequent double immunostaining showed that all biocytin-labeled parvalbumin-immunoreactive cells (n = 18) belonged to the FS cells (FS-PV cells), whereas all biocytin-labeled calbindinD28k-immunoreactive cells (n = 10) belonged to the LTS cells (LTS-Calb cells). 5. FS-PV cells had smooth or sparsely spiny dendrites, whereas LTS-Calb cells had dendrites with a modest number of spines but fewer than pyramidal cells. FS-PV cells showed denser axonal branches near their somata and extended axons in a more horizontal direction. Some of them could be identified as basket cells by the presence of terminal boutons surrounding somata of other cells. LTS-Calb cells extended their main axons more vertically up to layer I. 6. Double immunofluorescent staining revealed that very few cells in layer V showed immunoreactivity for both calcium-binding proteins but that most cells immunoreactive for the calcium-binding proteins in layer V were also immunoreactive for gamma-aminobutyric acid. 7. These results suggest that GABAergic nonpyramidal cells in layer V of neocortex can be divided into two functional groups on the basis of different firing modes, axonal distributions, and calcium-binding protein immunoreactivity: 1) FS-PV cells show repetitive firing by synaptic activation, have axonal arborizations that are more dense near their somata and oriented horizontally, and the cells exhibit parvalbumin immunoreactivity and 2) LTS cells show low-threshold spikes, have more vertical axonal arborizations up to layer I, and exhibit calbindinD28K immunoreactivity.

Responses of regular spiking and fast spiking cells in turtle visual cortex to light flashes

1998 ◽  
Vol 15 (5) ◽  
pp. 979-993 ◽  
Author(s):  
JAIME G. MANCILLA ◽  
MICHAEL FOWLER ◽  
PHILIP S. ULINSKI
Keyword(s):  
Visual Cortex ◽  
Action Potentials ◽  
Pyramidal Cells ◽  
High Gain ◽  
Light Intensities ◽  
Intensity Response ◽  
Light Stimuli ◽  
Fast Spiking ◽  
Light Flashes

Sharp electrodes were used to record light-evoked postsynaptic potentials (PSPs) from neurons in turtle visual cortex in an in vitro preparation of the geniculocortical pathway. Neurons were placed into four groups based on the firing patterns produced by intracellular current injections: regular spiking (RS), fast spiking (FS), intrinsic bursting (IB), and chattering (CH) cells. RS cells have been shown to be pyramidal cells while FS cells are typically interneurons. Light stimuli were diffuse, 1-s flashes of 640-nm light with intensities (I) varying from 0 to 104 photons μm−2 s−1. The response (R) in each case was the maximal amplitude of the light-evoked depolarizing PSP. Cells of all four types showed sigmoidal intensity–response (IR) functions with a linear rising phase for stimuli above the intensity threshold followed by saturation at high light intensities. Responses at high intensities were variable and some cells showed indications of supersaturation. Light-evoked PSPs had longer latencies and times-to-peak response in RS cells than they did in FS cells. RS cells fired action potentials as much as 200 ms later than did FS cells. Since responses recorded in RS cells at light intensities just above threshold are unlikely to involve contributions from other pyramidal cells, these data indicate that the geniculocortical or feedforward pathway to pyramidal cells has a high gain. The fact that FS cells fire well before RS cells suggests that feedforward inhibition plays a role in controlling the gain of the geniculocortical pathway.

Preparation of dextran–casein phosphopeptide conjugates, evaluation of its calcium binding capacity and digestion in vitro

2021 ◽  
pp. 129332
Author(s):  
Lan Jiang ◽  
Shuhong Li ◽  
Nan Wang ◽  
Shuang Zhao ◽  
Yue Chen ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Binding Capacity ◽  
Casein Phosphopeptide

scholarly journals Inhibitory interneurons of the human prefrontal cortex display conserved evolution of the phenotype and related genes

2009 ◽  
Vol 277 (1684) ◽  
pp. 1011-1020 ◽  
Author(s):  
Chet C. Sherwood ◽  
Mary Ann Raghanti ◽  
Cheryl D. Stimpson ◽  
Muhammad A. Spocter ◽  
Monica Uddin ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Calcium Binding ◽  
Amino Acid Level ◽  
Primate Evolution ◽  
Inhibitory Interneurons ◽  
Cognitive Domains ◽  
Inhibitory Circuitry ◽  
Show Evidence ◽  
Anthropoid Primates ◽  
And Migration

Inhibitory interneurons participate in local processing circuits, playing a central role in executive cognitive functions of the prefrontal cortex. Although humans differ from other primates in a number of cognitive domains, it is not currently known whether the interneuron system has changed in the course of primate evolution leading to our species. In this study, we examined the distribution of different interneuron subtypes in the prefrontal cortex of anthropoid primates as revealed by immunohistochemistry against the calcium-binding proteins calbindin, calretinin and parvalbumin. In addition, we tested whether genes involved in the specification, differentiation and migration of interneurons show evidence of positive selection in the evolution of humans. Our findings demonstrate that cellular distributions of interneuron subtypes in human prefrontal cortex are similar to other anthropoid primates and can be explained by general scaling rules. Furthermore, genes underlying interneuron development are highly conserved at the amino acid level in primate evolution. Taken together, these results suggest that the prefrontal cortex in humans retains a similar inhibitory circuitry to that in closely related primates, even though it performs functional operations that are unique to our species. Thus, it is likely that other significant modifications to the connectivity and molecular biology of the prefrontal cortex were overlaid on this conserved interneuron architecture in the course of human evolution.

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