Cellular Mechanisms of Thalamically Evoked Gamma Oscillations in Auditory Cortex

2001 ◽  
Vol 85 (3) ◽  
pp. 1235-1245 ◽  
Author(s):  
William Sukov ◽  
Daniel S. Barth
Keyword(s):  
Auditory Cortex ◽  
Field Potential ◽  
Electrode Array ◽  
Pyramidal Cells ◽  
Gamma Oscillations ◽  
Membrane Properties ◽  
Gamma Activity ◽  
Cellular Mechanisms ◽  
Gamma Frequency ◽  
Fast Oscillations

The purpose of this study was to clarify the neurogenesis of thalamically evoked gamma frequency (∼40 Hz) oscillations in auditory cortex by comparing simultaneously recorded extracellular and intracellular responses elicited with electrical stimulation of the posterior intralaminar nucleus of the thalamus (PIL). The focus of evoked gamma activity was located between primary and secondary auditory cortex using a 64-channel epipial electrode array, and all subsequent intracellular recordings and single-electrode field potential recordings were made at this location. These data indicate that PIL stimulation evokes gamma oscillations in auditory cortex by tonically depolarizing pyramidal cells in the supra- and infragranular layers. No cells revealed endogenous membrane properties capable of producing activity in the gamma frequency band when depolarized individually with injected current, but all displayed both sub- and supra-threshold responses time-locked to extracellular fast oscillations when the population was depolarized by PIL stimulation. We propose that cortical gamma oscillations may be produced and propagated intracortically by network interactions among large groups of neurons when mutually excited by modulatory input from the intralaminar thalamus and that these oscillations do not require specialized pacemaker cells for their neurogenesis.

scholarly journals Gamma activity accelerates during prefrontal development

2020 ◽  
Author(s):  
Sebastian H. Bitzenhofer ◽  
Jastyn A. Pöpplau ◽  
Ileana L. Hanganu-Opatz
Keyword(s):  
Prefrontal Cortex ◽  
Pyramidal Neurons ◽  
Temporal Dynamics ◽  
Rhythmic Activity ◽  
Gamma Oscillations ◽  
Gamma Activity ◽  
Oscillatory Activity ◽  
Gamma Frequency ◽  
Gamma Rhythms ◽  
Fast Oscillations

AbstractGamma oscillations are a prominent activity pattern in the cerebral cortex. While gamma rhythms have been extensively studied in the adult prefrontal cortex in the context of cognitive (dys)functions, little is known about their development. We addressed this issue by using extracellular recordings and optogenetic stimulations in mice across postnatal development. We show that fast rhythmic activity in the prefrontal cortex becomes prominent during the second postnatal week. While initially at about 15 Hz, fast oscillatory activity progressively accelerates with age and stabilizes within gamma frequency range (30-80 Hz) during the fourth postnatal week. Activation of layer 2/3 pyramidal neurons drives fast oscillations throughout development, yet the acceleration of their frequency follows similar temporal dynamics as the maturation of fast-spiking interneurons. These findings uncover the development of prefrontal gamma activity and provide a framework to examine the origin of abnormal gamma activity in neurodevelopmental disorders.

scholarly journals Gamma activity accelerates during prefrontal development

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Sebastian H Bitzenhofer ◽  
Jastyn A Pöpplau ◽  
Ileana Hanganu-Opatz
Keyword(s):  
Prefrontal Cortex ◽  
Pyramidal Neurons ◽  
Temporal Dynamics ◽  
Rhythmic Activity ◽  
Gamma Oscillations ◽  
Gamma Activity ◽  
Oscillatory Activity ◽  
Gamma Frequency ◽  
Gamma Rhythms ◽  
Fast Oscillations

Gamma oscillations are a prominent activity pattern in the cerebral cortex. While gamma rhythms have been extensively studied in the adult prefrontal cortex in the context of cognitive (dys)functions, little is known about their development. We addressed this issue by using extracellular recordings and optogenetic stimulations in mice across postnatal development. We show that fast rhythmic activity in the prefrontal cortex becomes prominent during the second postnatal week. While initially at about 15 Hz, fast oscillatory activity progressively accelerates with age and stabilizes within gamma frequency range (30–80 Hz) during the fourth postnatal week. Activation of layer 2/3 pyramidal neurons drives fast oscillations throughout development, yet the acceleration of their frequency follows similar temporal dynamics as the maturation of fast-spiking interneurons. These findings uncover the development of prefrontal gamma activity and provide a framework to examine the origin of abnormal gamma activity in neurodevelopmental disorders.

scholarly journals Afferent inputs to cortical fast-spiking interneurons organize pyramidal cell network oscillations at high-gamma frequencies (60–200 Hz)

2014 ◽  
Vol 112 (11) ◽  
pp. 3001-3011 ◽  
Author(s):  
Piotr Suffczynski ◽  
Nathan E. Crone ◽  
Piotr J. Franaszczuk
Keyword(s):  
Local Field ◽  
Local Field Potential ◽  
Field Potential ◽  
Pyramidal Cells ◽  
Gamma Oscillations ◽  
Cortical Activation ◽  
Gamma Activity ◽  
High Gamma ◽  
Fast Spiking ◽  
Gamma Frequencies

High-gamma activity, ranging in frequency between ∼60 Hz and 200 Hz, has been observed in local field potential, electrocorticography, EEG and magnetoencephalography signals during cortical activation, in a variety of functional brain systems. The origin of these signals is yet unknown. Using computational modeling, we show that a cortical network model receiving thalamic input generates high-gamma responses comparable to those observed in local field potential recorded in monkey somatosensory cortex during vibrotactile stimulation. These high-gamma oscillations appear to be mediated mostly by an excited population of inhibitory fast-spiking interneurons firing at high-gamma frequencies and pacing excitatory regular-spiking pyramidal cells, which fire at lower rates but in phase with the population rhythm. The physiological correlates of high-gamma activity, in this model of local cortical circuits, appear to be similar to those proposed for hippocampal ripples generated by subsets of interneurons that regulate the discharge of principal cells.

Transient Depression of Excitatory Synapses on Interneurons Contributes to Epileptiform Bursts During Gamma Oscillations in the Mouse Hippocampal Slice

2005 ◽  
Vol 94 (2) ◽  
pp. 1225-1235 ◽  
Author(s):  
Roger D. Traub ◽  
Isabel Pais ◽  
Andrea Bibbig ◽  
Fiona E.N. LeBeau ◽  
Eberhard H. Buhl ◽  
...  
Keyword(s):  
Metabotropic Glutamate Receptor ◽  
Hippocampal Slices ◽  
Pyramidal Cells ◽  
Gamma Oscillations ◽  
Network Activity ◽  
Excitatory Synapses ◽  
Metabotropic Glutamate ◽  
Gamma Frequency ◽  
Gamma Rhythm ◽  
Fast Oscillations

Persistent gamma frequency (30–70 Hz) network oscillations occur in hippocampal slices under conditions of metabotropic glutamate receptor (mGluR) activation. Excessive mGluR activation generated a bistable pattern of network activity during which epochs of gamma oscillations of increasing amplitude were terminated by synchronized bursts and very fast oscillations (>70 Hz). We provide experimental evidence that, during this behavior, pyramidal cell-to-interneuron synaptic depression takes place, occurring spontaneously during the gamma rhythm and associated with the onset of epileptiform bursts. We further provide evidence that excitatory postsynaptic potentials (EPSPs) in pyramidal cells are potentiated during the interburst gamma oscillation. When these two types of synaptic plasticity are incorporated, phenomenologically, into a network model previously shown to account for many features of persistent gamma oscillations, we find that epochs of gamma do indeed alternate with epochs of very fast oscillations and epileptiform bursts. Thus the same neuronal network can generate either gamma oscillations or epileptiform bursts, in a manner depending on the degree of network drive and network-induced fluctuations in synaptic efficacies.

Carbachol Induces Fast Oscillations in the Medial but not in the Lateral Entorhinal Cortex of the Isolated Guinea Pig Brain

1999 ◽  
Vol 82 (5) ◽  
pp. 2441-2450 ◽  
Author(s):  
Solange van der Linden ◽  
Ferruccio Panzica ◽  
Marco de Curtis
Keyword(s):  
Guinea Pig ◽  
Entorhinal Cortex ◽  
Gamma Oscillations ◽  
Gamma Activity ◽  
Oscillatory Activity ◽  
Medial Entorhinal Cortex ◽  
Arterial Perfusion ◽  
Fast Oscillations ◽  
Guinea Pig Brain

Fast oscillations at 25–80 Hz (gamma activity) have been proposed to play a role in attention-related mechanisms and synaptic plasticity in cortical structures. Recently, it has been demonstrated that the preservation of the entorhinal cortex is necessary to maintain gamma oscillations in the hippocampus. Because gamma activity can be reproduced in vitro by cholinergic activation, this study examined the characteristics of gamma oscillations induced by arterial perfusion or local intracortical injections of carbachol in the entorhinal cortex of the in vitro isolated guinea pig brain preparation. Shortly after carbachol administration, fast oscillatory activity at 25.2–28.2 Hz was observed in the medial but not in the lateral entorhinal cortex. Such activity was transiently associated with oscillations in the theta range that showed a variable pattern of distribution in the entorhinal cortex. No oscillatory activity was observed when carbachol was injected in the lateral entorhinal cortex. Gamma activity in the medial entorhinal cortex showed a phase reversal at 200–400 μm, had maximal amplitude at 400–500 μm depth, and was abolished by arterial perfusion of atropine (5 μM). Local carbachol application in the medial entorhinal cortex induced gamma oscillations in the hippocampus, whereas no oscillations were observed in the amygdala and in the piriform, periamygdaloid, and perirhinal cortices ipsilateral and contralateral to the carbachol injection. Hippocampal oscillations had higher frequency than the gamma activity recorded in the entorhinal cortex, suggesting the presence of independent generators in the two structures. The selective ability of the medial but not the lateral entorhinal cortex to generate gamma activity in response to cholinergic activation suggests a differential mode of signal processing in entorhinal cortex subregions.

Spike Timing of Lacunosom-Moleculare Targeting Interneurons and CA3 Pyramidal Cells During High-Frequency Network Oscillations In Vitro

2007 ◽  
Vol 98 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Jay Spampanato ◽  
Istvan Mody
Keyword(s):  
High Frequency ◽  
Epileptiform Activity ◽  
Field Potential ◽  
Pyramidal Cells ◽  
Gamma Oscillations ◽  
Spike Timing ◽  
Network Activity ◽  
Network Oscillations ◽  
Ca3 Pyramidal Cells

Network activity in the 200- to 600-Hz range termed high-frequency oscillations (HFOs) has been detected in epileptic tissue from both humans and rodents and may underlie the mechanism of epileptogenesis in experimental rodent models. Slower network oscillations including theta and gamma oscillations as well as ripples are generated by the complex spike timing and interactions between interneurons and pyramidal cells of the hippocampus. We determined the activity of CA3 pyramidal cells, stratum oriens lacunosum-moleculare (O-LM) and s. radiatum lacunosum-moleculare (R-LM) interneurons during HFO in the in vitro low-Mg2+ model of epileptiform activity in GIN mice. In these animals, interneurons can be identified prior to cell-attached recordings by the expression of green-fluorescent protein (GFP). Simultaneous local field potential recordings from s. pyramidale and on-cell recordings of individual interneurons and principal cells revealed three primary firing behaviors of the active cells: 36% of O-LM interneurons and 60% of pyramidal cells fired action potentials at high frequencies during the HFO. R-LM interneurons were biphasic in that they fired at high frequency at the beginning of the HFO but stopped firing before its end. When considering only the highest frequency component of the oscillations most pyramidal cells fired on the rising phase of the oscillation. These data provide evidence for functional distinction during HFOs within otherwise homogeneous groups of O-LM interneurons and pyramidal cells.

scholarly journals Granule cell excitability regulates gamma and beta oscillations in a model of the olfactory bulb dendrodendritic microcircuit

2016 ◽  
Vol 116 (2) ◽  
pp. 522-539 ◽  
Author(s):  
Bolesław L. Osinski ◽  
Leslie M. Kay
Keyword(s):  
Olfactory Bulb ◽  
Granule Cells ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Causal Link ◽  
Beta Oscillations ◽  
Gamma Frequency ◽  
Voltage Dependent ◽  
Nmda Channels ◽  
Beta Frequency

Odors evoke gamma (40–100 Hz) and beta (20–30 Hz) oscillations in the local field potential (LFP) of the mammalian olfactory bulb (OB). Gamma (and possibly beta) oscillations arise from interactions in the dendrodendritic microcircuit between excitatory mitral cells (MCs) and inhibitory granule cells (GCs). When cortical descending inputs to the OB are blocked, beta oscillations are extinguished whereas gamma oscillations become larger. Much of this centrifugal input targets inhibitory interneurons in the GC layer and regulates the excitability of GCs, which suggests a causal link between the emergence of beta oscillations and GC excitability. We investigate the effect that GC excitability has on network oscillations in a computational model of the MC-GC dendrodendritic network with Ca2+-dependent graded inhibition. Results from our model suggest that when GC excitability is low, the graded inhibitory current mediated by NMDA channels and voltage-dependent Ca2+ channels (VDCCs) is also low, allowing MC populations to fire in the gamma frequency range. When GC excitability is increased, the activation of NMDA receptors and other VDCCs is also increased, allowing the slow decay time constants of these channels to sustain beta-frequency oscillations. Our model argues that Ca2+ flow through VDCCs alone could sustain beta oscillations and that the switch between gamma and beta oscillations can be triggered by an increase in the excitability state of a subpopulation of GCs.

scholarly journals Peak gamma frequency and cortical laminar processing are modified across the healthy menstrual cycle

2017 ◽  
Author(s):  
R.L. Sumner ◽  
R.L. McMilllan ◽  
A. D. Shaw ◽  
K.D. Singh ◽  
F. Sundram ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Luteal Phase ◽  
Pyramidal Cells ◽  
Gamma Oscillations ◽  
Gonadal Hormones ◽  
Follicular Phase ◽  
Cycle Phase ◽  
Functional Changes ◽  
Gamma Frequency ◽  
Cortical Laminar

AbstractFluctuations in gonadal hormones over the course of the menstrual cycle are known to cause functional brain changes and are thought to modulate changes in the balance of cortical excitation and inhibition. Animal research has shown this occurs primarily via the major metabolite of progesterone, allopregnanolone, and its action as a positive allosteric modulator of the GABAA receptor. Our study used EEG to record gamma oscillations induced in the visual cortex using stationary and moving gratings. Recordings took place during twenty females’ mid-luteal phase when progesterone and oestradiol are highest, and early follicular phase when progesterone and oestradiol are lowest. Significantly higher (~5 Hz) gamma frequency was recorded during the luteal compared to the follicular phase for both stimuli types. Using dynamic causal modelling these changes were linked to stronger self-inhibition of superficial pyramidal cells in the luteal compared to the follicular phase. In addition the connection from inhibitory interneurons to deep pyramidal cells was found to be stronger in the follicular compared to the luteal phase. These findings show that complex functional changes in synaptic microcircuitry occur across the menstrual cycle and that menstrual cycle phase should be taken into consideration when including female participants in research into gamma-band oscillations.

Subcortical Modulation of High-Frequency (Gamma Band) Oscillating Potentials in Auditory Cortex

1997 ◽  
Vol 78 (2) ◽  
pp. 573-581 ◽  
Author(s):  
Barbara Brett ◽  
Daniel S. Barth
Keyword(s):  
Electrical Stimulation ◽  
Auditory Cortex ◽  
High Frequency ◽  
High Spatial Resolution ◽  
Electrode Array ◽  
Gamma Oscillations ◽  
Gamma Band ◽  
Nucleus Basalis ◽  
Subcortical Nuclei ◽  
Cortical Focus

Brett, Barbara and Daniel S. Barth. Subcortical modulation of high-frequency (gamma band) oscillating potentials in auditory cortex. J. Neurophysiol. 78: 573–581, 1997. The purpose of this study was to use depth electrical stimulation and retrograde horseradish peroxidase (HRP) labeling to determine what role certain subcortical nuclei play in the neurogenesis of high-frequency gamma (∼40 Hz) oscillations in rat auditory cortex. Evoked and spontaneous electrocortical oscillations were recorded with the use of a high-spatial-resolution multichannel epipial electrode array while electrical stimulation was delivered to the posterior intralaminar (PIL) region of the ventral acoustic thalamus and to the centrolateral nucleus (CL) and the nucleus basalis (NB), which have been previously implicated in the production of cortical gamma oscillations. PIL stimulation consistently evoked gamma oscillations confined to a location between primary and secondary auditory cortex, corresponding to the region where spontaneous gamma oscillations were also recorded. Stimulation of the CL and NB did not evoke gamma oscillations in auditory cortex. HRP placed in the cortical focus of evoked gamma oscillations labeled cell bodies in the PIL, and in more lateral regions of the ventral acoustic thalamus, which on subsequent stimulation also evoked gamma oscillations in auditory cortex. No cells were labeled in either the CL or NB. These results indicate that the PIL and the lateral regions of ventral acoustic thalamus provide anatomically distinct input to auditory cortex and may play an exclusive and modality-specific role in modulating gamma oscillations in the auditory system.

scholarly journals Temporal redistribution of inhibition over neuronal subcellular domains underlies state-dependent rhythmic change of excitability in the hippocampus

2014 ◽  
Vol 369 (1635) ◽  
pp. 20120518 ◽  
Author(s):  
Peter Somogyi ◽  
Linda Katona ◽  
Thomas Klausberger ◽  
Bálint Lasztóczi ◽  
Tim J. Viney
Keyword(s):  
Pyramidal Cell ◽  
Initial Segment ◽  
Field Potential ◽  
Inverse Correlation ◽  
Pyramidal Cells ◽  
Axon Initial Segment ◽  
Gamma Activity ◽  
Gabaergic Interneurons ◽  
Potential Oscillations ◽  
Network States

The behaviour-contingent rhythmic synchronization of neuronal activity is reported by local field potential oscillations in the theta, gamma and sharp wave-related ripple (SWR) frequency ranges. In the hippocampus, pyramidal cell assemblies representing temporal sequences are coordinated by GABAergic interneurons selectively innervating specific postsynaptic domains, and discharging phase locked to network oscillations. We compare the cellular network dynamics in the CA1 and CA3 areas recorded with or without anaesthesia. All parts of pyramidal cells, except the axon initial segment, receive GABA from multiple interneuron types, each with distinct firing dynamics. The axon initial segment is exclusively innervated by axo-axonic cells, preferentially firing after the peak of the pyramidal layer theta cycle, when pyramidal cells are least active. Axo-axonic cells are inhibited during SWRs, when many pyramidal cells fire synchronously. This dual inverse correlation demonstrates the key inhibitory role of axo-axonic cells. Parvalbumin-expressing basket cells fire phase locked to field gamma activity in both CA1 and CA3, and also strongly increase firing during SWRs, together with dendrite-innervating bistratified cells, phasing pyramidal cell discharge. Subcellular domain-specific GABAergic innervation probably developed for the coordination of multiple glutamatergic inputs on different parts of pyramidal cells through the temporally distinct activity of GABAergic interneurons, which differentially change their firing during different network states.

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