scholarly journals Oscillations synchronize amygdala-to-prefrontal primate circuits during aversive learning

2017 ◽  
Author(s):  
Aryeh Taub ◽  
Rony Paz
Keyword(s):  
Information Transfer ◽  
Phase Locking ◽  
Aversive Conditioning ◽  
List Type ◽  
Aversive Learning ◽  
Transfer Error ◽  
Theta Phase ◽  
Conditioned Responses ◽  
Odor Conditioning ◽  
Theta Range

SummaryThe contribution of oscillatory synchrony in the primate amygdala-prefrontal pathway to aversive learning remains unknown. We found increased power and phase synchrony in the theta range during aversive conditioning. The synchrony was linked to single-unit spiking and exhibited specific directionality between input and output measures in each region. Although it was correlated with the development of conditioned responses, it declined once the association stabilized. The results suggest that amygdala spikes aid to synchronize ACC activity and transfer error-signal information to support memory formation.HighlightsTone-odor conditioning induces theta phase-reset in primate amygdala and dACCA directional phase-locking develops between amygdala spikes and dACC ThetaInformation transfer from Amygdala to dACC decreases once memory stabilizes

scholarly journals Rhythmic Accessibility to Sequential Working Memory in a Theta Phase-Dependent Manner

2021 ◽  
Author(s):  
Takuya Ideriha ◽  
Junichi Ushiyama
Keyword(s):  
Working Memory ◽  
Memory Storage ◽  
Dependent Manner ◽  
Random Interval ◽  
Phase Coding ◽  
Short Period ◽  
Theta Phase ◽  
Sequential Information ◽  
The Impact ◽  
Theta Range

Working memory is active short-term memory storage that is easily accessible and underlies various activities, such as maintaining phone numbers in mind for a short period [1,2]. There is accumulating theoretical and physiological evidence that memorized items are represented rhythmically by neural oscillation in the theta range (4-7 Hz) [3,4]. However, the impact of this process on human behavior is yet to be examined. Here we show that simply memorizing sequential information affects a behavioral index (i.e., reaction time, RT) in a rhythmic manner. In the main experiment (Experiment 1), we measured RTs to a visual probe that appeared at one of two sequentially memorized locations after a random interval. Consequently, RTs to the first and second probes each fluctuated in the theta range as a function of the random interval, and the phases of the two theta fluctuations were not in phase or anti-phase, but shifted by approximately 270 degree. Interestingly, the 270 degree phase difference corresponded to the rhythm of "phase coding", where sequential information is represented on the specific phase of theta oscillation [5-7]. These relationships were not observed in tasks simply requiring attention (Experiment 2) or memorization (Experiment 3) of spatial locations without sequential order. In conclusion, the current results demonstrate that our behavior fluctuates when recalling memorized sequential items in the theta-range, suggesting that accessibility to sequential working memory is rhythmic rather than stable, possibly reflecting theta-phase coding.

A NEUROBIOLOGICAL THEORY OF MEANING IN PERCEPTION PART III: MULTIPLE CORTICAL AREAS SYNCHRONIZE WITHOUT LOSS OF LOCAL AUTONOMY

2003 ◽  
Vol 13 (10) ◽  
pp. 2845-2856 ◽  
Author(s):  
WALTER J. FREEMAN ◽  
GYöNGYI GAÁL ◽  
REBECKA JORSTEN
Keyword(s):  
Information Transfer ◽  
Phase Locking ◽  
Pulse Frequency ◽  
Inhibitory Neurons ◽  
Oscillatory Activity ◽  
Electrode Arrays ◽  
Ensemble Averaging ◽  
Pulse Frequency Modulation ◽  
Cortical Areas ◽  
Gamma Range

Information transfer and integration among functionally distinct areas of cerebral cortex of oscillatory activity require some degree of phase synchrony of the trains of action potentials that carry the information prior to the integration. However, propagation delays are obligatory. Delays vary with the lengths and conduction velocities of the axons carrying the information, causing phase dispersion. In order to determine how synchrony is achieved despite dispersion, we recorded EEG signals from multiple electrode arrays on five cortical areas in cats and rabbits, that had been trained to discriminate visual or auditory conditioned stimuli. Analysis by time-lagged correlation, multiple correlation and PCA, showed that maximal correlation was at zero lag and averaged 0.7, indicating that 50% of the power in the gamma range among the five areas was at zero lag irrespective of phase or frequency. There were no stimulus-related episodes of transiently increased phase locking among the areas, nor EEG "bursts" of transiently increased amplitude above the sustained level of synchrony. Three operations were identified to account for the sustained correlation. Cortices broadcast their outputs over divergent–convergent axonal pathways that performed spatial ensemble averaging; synaptic interactions between excitatory and inhibitory neurons in cortex operated as band pass filters for gamma; and signal coarse-graining by pulse frequency modulation at trigger zones enhanced correlation. The conclusion is that these three operations enable continuous linkage of multiple cortical areas by activity in the gamma range, providing the basis for coordinated cortical output to other parts of the brain, despite varying axonal conduction delays, something like the back plane of a main frame computer.

scholarly journals Pitfalls in the Assessment of Brain-Machine Interfaces Using Information Transfer Rate

2017 ◽  
Author(s):  
Mikhail A. Lebedev ◽  
Po-He Tseng ◽  
Peter J. Ifft ◽  
Dennis Ochei ◽  
Miguel A.L. Nicolelis
Keyword(s):  
Motor Performance ◽  
Transfer Rate ◽  
Information Transfer ◽  
List Type ◽  
Brain Machine Interfaces ◽  
Practical Applications ◽  
Information Transfer Rate ◽  
Recording Channels ◽  
Transfer Of Information

AbstractInformation transfer rate (ITR), measured in bits/s, can be applied to evaluate motor performance, including the capacity of brain-machine interfaces (BMIs) to control external actuators. In a 2013 article entitled “Transfer of information by BMI” and published in Neuroscience, Tehovnik and his colleagues utilized ITR to assess the performance of several BMIs reported in the literature. We examined these analyses closely and found several fundamental flaws in their evaluation of ITR. Here we discuss the pitfalls in Tehovnik’s measurements of ITR, as well as several other issues raised in “Transfer of information by BMI”, including the claim that BMIs cannot be a reasonable option for paralyzed patients.HighlightsInformation transfer rate is discussed for BMI experiments, where subjects reach to targets.Task settings, not just the number of possible targets, are important to calculate information correctly.Active tactile exploration can be quantified as information transfer, but the number of targets is insufficient for such quantification.Information transfer rate increases with the number of neural recording channels.For practical applications, improvement in quality of life is essential, not information transfer rate per se.

scholarly journals A brainstem-central amygdala circuit underlies defensive responses to learned threats

2019 ◽  
Author(s):  
Yiran Gu ◽  
Elena M. Vazey ◽  
Gary Aston-Jones ◽  
Longnian Lin ◽  
Joseph E. LeDoux ◽  
...  
Keyword(s):  
Locus Coeruleus ◽  
Central Nucleus ◽  
Aversive Learning ◽  
Defensive Responses ◽  
Behavioral Expression ◽  
Bidirectional Modulation ◽  
Conditioned Responses ◽  
Lateral Nucleus ◽  
Conditioned Cues

AbstractNorepinephrine (NE) plays a central role in the acquisition of aversive learning via actions in the lateral nucleus of the amygdala (LA)1,2. However, the function of NE in expression of aversively-conditioned responses has not been established. Given the role of the central nucleus of the amygdala (CeA) in the expression of such behaviors3, and the presence of NE projections in this brain nucleus, we assessed the effects of NE activity in the CeA on behavioral expression using receptor-specific pharmacology and cell-and projection-specific chemogenetic manipulations. We found that inhibition and activation of locus coeruleus (LC) neurons decreases and increases freezing to aversively conditioned cues, respectively. We then show that locally inhibiting or activating LC terminals in CeA is sufficient to achieve this bidirectional modulation of defensive reactions. These findings support the hypothesis that LC projections to CeA are required for the expression of defensive responses elicited by conditioned threats.

Visual P2 component is related to theta phase-locking

2007 ◽  
Vol 426 (3) ◽  
pp. 181-186 ◽  
Author(s):  
R. Freunberger ◽  
W. Klimesch ◽  
M. Doppelmayr ◽  
Y. Höller
Keyword(s):  
Phase Locking ◽  
Theta Phase

Information Transfer Between Rhythmically Coupled Networks: Reading the Hippocampal Phase Code

2001 ◽  
Vol 13 (12) ◽  
pp. 2743-2761 ◽  
Author(s):  
Ole Jensen
Keyword(s):  
Information Transfer ◽  
Computational Models ◽  
Brain Networks ◽  
Place Cells ◽  
Phase Code ◽  
Current Location ◽  
Coupled Networks ◽  
Plausible Mechanism ◽  
Theta Phase ◽  
Oscillatory Network

There are numerous reports on rhythmic coupling between separate brain networks. It has been proposed that this rhythmic coupling indicates exchange of information. So far, few computational models have been proposed that explore this principle and its potential computational benefits. Recent results on hippocampal place cells of the rat provide new insight; it has been shown that information about space is encoded by the firing of place cells with respect to the phase of the ongoing theta rhythm. This principle is termed phase coding and suggests that upcoming locations (predicted by the hippocampus) are encoded by cells firing late in the theta cycle, whereas current location is encoded by early firing in the theta cycle. A network reading the hippocampal output must inevitably also receive an oscillatory theta input in order to decipher the phase-coded firing patterns. In this article, I propose a simple physiologically plausible mechanism implemented as an oscillatory network that can decode the hippocampal output. By changing only the phase of the theta input to the decoder, qualitatively different information is transferred: the theta phase determines whether representations of current or upcoming locations are read by the decoder. The proposed mechanism provides a computational principle for information transfer between oscillatory networks and might generalize to brain networks beyond the hippocampal region.

scholarly journals Dynamical Phase Modulation and Oscillatory Detuning in Applied Neurostimulation

2020 ◽  
Vol 7 (1) ◽  
pp. 01-10
Author(s):  
Denis Larrivee
Keyword(s):  
Information Exchange ◽  
Phase Modulation ◽  
Information Transfer ◽  
Phase Locking ◽  
Motor Planning ◽  
Higher Order ◽  
Brain Organization ◽  
Dynamical Phase ◽  
Dynamical Features ◽  
Global Brain

Neural architectures that are operative in higher order cognition, including consciousness, memory, and motor planning, undergo complex changes in global organization during neurological disease. Increasingly, neurostimulation is therapeutically used for restoring these functions, although the mechanisms of restoration are largely unknown. Extant studies reveal, on the other hand, that non-linear and dynamical principles govern global brain organization, seen in operational features such as persistence, stability, flexibility and non-localization that are likely to be evoked by neurostimulation. These dynamical features are instantiated in neural oscillations, a key mechanism regulating brain function and communication. Due to stochastic influences, oscillator synchronization and desynchronization exhibit limit cycle attractor dynamics, which are characterized by persistent phase modulation rather than fixed point, stationary phase locking. Phase modulation governs information exchange by temporally gating transfer and guiding the trajectory of information distribution. Activation of attractor forces by modest input drive induces dynamic, phase difference detuning that results in phase preference shifts, whereas strong input drive induces low stability phase relations that promote oscillator dissociation and new pair formation. These dynamical features of oscillator behavior are likely to facilitate information transfer to neural networks during neurostimulation of higher order functions.

scholarly journals ProxLogs: Miniaturised proximity loggers for monitoring association behaviour in small mammals

2021 ◽  
Author(s):  
Lucinda Kirkpatrick ◽  
Ivan Hererra Olivares ◽  
Apia Massawe ◽  
Christopher Sabuni ◽  
Herwig Leirs ◽  
...  
Keyword(s):  
Open Source ◽  
Disease Transmission ◽  
Information Transfer ◽  
Low Cost ◽  
Rapid Development ◽  
Natural World ◽  
Consumer Electronics ◽  
Low Energy ◽  
List Type ◽  
Bluetooth Low Energy

AbstractThe ability to monitor associations between wild animals is essential for understanding the processes governing gene transfer, information transfer, competition, predation and disease transmission.Until recently, such insights have been confined to large, visible or captive animals. However, the rapid development of miniature sensors for consumer electronics is allowing ecologists to monitor the natural world in ways previously considered impossible.Here we describe miniature (<1g) proximity loggers we have developed that use Bluetooth Low Energy transmission to register contacts between individuals. Our loggers are open source, low cost, rechargeable, able to store up to 2000 contacts, can be programmed in situ and can download data remotely or through a mobile phone application, increasing their utility in remote areas or with species which are challenging to recapture.We successfully trialled our loggers in a range of field realistic conditions, demonstrating that Bluetooth Low Energy is capable of logging associations in structurally complex habitats, and that changes in received signal strength can be equated to short range changes in distance between loggers. Furthermore, we tested the system on starlings (Sturnidae vulgaris).The ability to include other sensors is retained in our prototypes, allowing for the potential integration of physiological and behavioural inference into social networks derived from our approach. Due to its open source nature, small size, flexibility of use and the active research currently being undertaken with Bluetooth Low Energy, we believe that our approach is a valuable addition to the biologging toolkit.

scholarly journals Aversive learning strengthens episodic memory in both adolescents and adults

2019 ◽  
Author(s):  
Alexandra O. Cohen ◽  
Nicholas G. Matese ◽  
Anastasia Filimontseva ◽  
Xinxu Shen ◽  
Tracey C. Shi ◽  
...  
Keyword(s):  
Recognition Memory ◽  
Episodic Memory ◽  
Age Groups ◽  
Autonomic Arousal ◽  
Aversive Learning ◽  
Emotional Experiences ◽  
Aversive Events ◽  
Adult Humans ◽  
Adolescents And Adults ◽  
Conditioned Responses

AbstractAdolescence is often filled with positive and negative emotional experiences that may change how individuals remember and respond to stimuli in their environment. In adults, aversive events can both enhance memory for associated stimuli as well as generalize to enhance memory for unreinforced but conceptually related stimuli. The present study tested whether learned aversive associations similarly lead to better memory and generalization across a category of stimuli in adolescents. Participants completed an olfactory Pavlovian category conditioning task in which trial-unique exemplars from one of two categories were partially reinforced with an aversive odor. Participants then returned 24-hours later to complete a surprise recognition memory test. We found better corrected recognition memory for the reinforced versus the unreinforced category of stimuli in both adults and adolescents. Further analysis revealed that enhanced recognition memory was driven specifically by better memory for the reinforced exemplars. Autonomic arousal during learning was also related to subsequent memory. These findings build on previous work in adolescent and adult humans and rodents showing comparable acquisition of aversive Pavlovian conditioned responses across age groups and demonstrate that memory for stimuli with an acquired aversive association is enhanced in both adults and adolescents.

scholarly journals Glutamatergic drive along the septo-temporal axis of hippocampus boosts prelimbic oscillations in the neonatal mouse

2017 ◽  
Author(s):  
Joachim Ahlbeck ◽  
Lingzhen Song ◽  
Mattia Chini ◽  
Antonio Candela ◽  
Sebastian H. Bitzenhofer ◽  
...  
Keyword(s):  
Long Range ◽  
Hippocampal Neurons ◽  
High Efficiency ◽  
Dorsal Hippocampus ◽  
Phase Locking ◽  
Ventral Hippocampus ◽  
Neuronal Firing ◽  
Projection Neurons ◽  
List Type ◽  
Axonal Projections

SUMMARYThe long-range coupling within prefrontal-hippocampal networks that account for cognitive performance emerges early in life. The discontinuous hippocampal theta bursts have been proposed to drive the generation of neonatal prefrontal oscillations, yet the cellular substrate of these early interactions is still unresolved. Here, we selectively target optogenetic manipulation of glutamatergic projection neurons in the CA1 area of either dorsal or intermediate/ventral hippocampus at neonatal age to elucidate their contribution to the emergence of prefrontal oscillatory entrainment. We show that despite stronger theta and ripples power in dorsal hippocampus, the prefrontal cortex is mainly coupled with intermediate/ventral hippocampus by phase-locking of neuronal firing via dense direct axonal projections. Theta band-confined activation by light of pyramidal neurons in intermediate/ventral but not dorsal CA1 that were transfected by in utero electroporation with high-efficiency channelrhodopsin boosts prefrontal oscillations. Our data causally elucidates the cellular origin of the long-range coupling in the developing brain.HighlightsNeonatal theta bursts, sharp waves and ripples vary along septo-temporal axisHippocampal activity times prefrontal oscillations via direct axonal projectionsSelective hippocampal targeting along septo-temporal axis causes precise firingLight stimulation of hippocampal neurons at 8 Hz boosts prefrontal oscillations

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