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Biological Psychiatry May 2018Associative memory formation is essential for an animal's survival by ensuring adaptive behavioral responses in an ever-changing environment. This is particularly... (Review)
Review
Associative memory formation is essential for an animal's survival by ensuring adaptive behavioral responses in an ever-changing environment. This is particularly important under conditions of immediate threats such as in fear learning. One of the key brain regions involved in associative fear learning is the amygdala. The basolateral amygdala is the main entry site for sensory information to the amygdala complex, and local plasticity in excitatory basolateral amygdala principal neurons is considered to be crucial for learning of conditioned fear responses. However, activity and plasticity of excitatory circuits are tightly controlled by local inhibitory interneurons in a spatially and temporally defined manner. In this review, we provide an updated view on how distinct interneuron subtypes in the basolateral amygdala contribute to the acquisition and extinction of conditioned fear memories.
Topics: Amygdala; Animals; Conditioning, Psychological; Fear; Humans; Nerve Net; Neural Inhibition
PubMed: 29174478
DOI: 10.1016/j.biopsych.2017.10.006 -
Current Opinion in Neurobiology Jun 2014
Topics: Animals; Brain; Humans; Neural Inhibition; Neurons; Synapses
PubMed: 24742530
DOI: 10.1016/j.conb.2014.03.014 -
Neuron Sep 2012Until recently, the study of plasticity of neural circuits focused almost exclusively on potentiation and depression at excitatory synapses on principal cells. Other... (Review)
Review
Until recently, the study of plasticity of neural circuits focused almost exclusively on potentiation and depression at excitatory synapses on principal cells. Other elements in the neural circuitry, such as inhibitory synapses on principal cells and the synapses recruiting interneurons, were assumed to be relatively inflexible, as befits a role of inhibition in maintaining stable levels and accurate timing of neuronal activity. It is now evident that inhibition is highly plastic, with multiple underlying cellular mechanisms. This Review considers these recent developments, focusing mainly on functional and structural changes in GABAergic inhibition of principal cells and long-term plasticity of glutamateric recruitment of inhibitory interneurons in the mammalian forebrain. A major challenge is to identify the adaptive roles of these different forms of plasticity, taking into account the roles of inhibition in the regulation of excitability, generation of population oscillations, and precise timing of neuronal firing.
Topics: Animals; GABAergic Neurons; Models, Biological; Nerve Net; Neural Inhibition; Neuronal Plasticity
PubMed: 22998865
DOI: 10.1016/j.neuron.2012.07.030 -
Current Opinion in Neurobiology Apr 2017The hippocampus is crucial for the formation and recall of long-term memories about people, places, objects, and events. Capitalizing on high-resolution microscopy, in... (Review)
Review
The hippocampus is crucial for the formation and recall of long-term memories about people, places, objects, and events. Capitalizing on high-resolution microscopy, in vivo electrophysiology, and genetic manipulation, recent research in rodents provides evidence for hippocampal ensemble coding on the spatial, episodic, and contextual dimensions. Here we highlight the functional contribution of newly described long-range connections between hippocampus and cortical areas, and the relative impact of inhibitory and excitatory dynamics in generating behaviorally relevant population activity. Our goal is to provide an integrated view of hippocampal circuit function to understand mnemonic computations at the systems and cellular levels that underlie adaptive learned behaviors.
Topics: Animals; Cerebral Cortex; Hippocampus; Learning; Memory; Neural Inhibition
PubMed: 28477511
DOI: 10.1016/j.conb.2017.04.005 -
Current Opinion in Neurobiology Apr 2017Inhibitory circuits are essential for brain function. Our understanding of their synaptic organization has advanced extensively with the identification and... (Review)
Review
Inhibitory circuits are essential for brain function. Our understanding of their synaptic organization has advanced extensively with the identification and classification of an impressive variety of neuron groups, receptor types, and patterns of connectivity. However, the conceptual discussion regarding the role of in neural circuits still revolves around the idea that its primary role is to regulate circuit excitability. Here, I will focus on recent findings from cortical circuits and argue that inhibitory circuits are central to the integration of incoming inputs and can promote sophisticated fine-scale control of local circuits. I propose that inhibitory circuits should not be viewed so much as brakes on principal neurons activity, but as primary contributors to a variety of neural network functions.
Topics: Animals; Humans; Nerve Net; Neural Inhibition; Neurons
PubMed: 28012992
DOI: 10.1016/j.conb.2016.12.003 -
Biological Psychiatry May 2017Brain function relies on the ability of neural networks to maintain stable levels of activity, while experiences sculpt them. In the neocortex, the balance between... (Review)
Review
Brain function relies on the ability of neural networks to maintain stable levels of activity, while experiences sculpt them. In the neocortex, the balance between activity and stability relies on the coregulation of excitatory and inhibitory inputs onto principal neurons. Shifts of excitation or inhibition result in altered excitability impaired processing of incoming information. In many neurodevelopmental and neuropsychiatric disorders, the excitability of local circuits is altered, suggesting that their pathophysiology may involve shifts in synaptic excitation, inhibition, or both. Most studies focused on identifying the cellular and molecular mechanisms controlling network excitability to assess whether they may be altered in animal models of disease. The impact of changes in excitation/inhibition balance on local circuit and network computations is not clear. Here we report findings on the integration of excitatory and inhibitory inputs in healthy cortical circuits and discuss how shifts in excitation/inhibition balance may relate to pathological phenotypes.
Topics: Animals; Humans; Neocortex; Neural Inhibition; Neurophysiology; Synaptic Transmission
PubMed: 27865453
DOI: 10.1016/j.biopsych.2016.09.017 -
The Journal of Neuroscience : the... Jan 2022Response inhibition is an essential aspect of cognitive control that is necessary for terminating inappropriate preplanned or ongoing responses. Response-selective... (Review)
Review
Response inhibition is an essential aspect of cognitive control that is necessary for terminating inappropriate preplanned or ongoing responses. Response-selective stopping represents a complex form of response inhibition where only a subcomponent of a multicomponent action must be terminated. In this context, a substantial response delay emerges on unstopped effectors after the cued effector is successfully stopped. This response delay has been termed the stopping interference effect. Converging lines of evidence indicate that this effect results from a global response inhibition mechanism that is recruited regardless of the stopping context. However, behavioral observations reveal that the stopping interference effect may not always occur during selective stopping. This review summarizes the behavioral and neural signatures of response inhibition during selective stopping. An overview of selective stopping contexts and the stopping interference effect is provided. A "restart" model of selective stopping is expanded on in light of recent neurophysiological evidence of selective and nonselective response inhibition. Factors beyond overt action cancellation that contribute to the stopping interference effect are discussed. Finally, a pause-then-cancel model of action stopping is presented as a candidate framework to understand stopping interference during response-selective stopping. The extant literature indicates that stopping interference may result from both selective and nonselective response inhibition processes, which can be amplified or attenuated by response conflict, task familiarity, and functional coupling.
Topics: Electroencephalography; Humans; Inhibition, Psychological; Motor Cortex; Neural Inhibition; Psychomotor Performance; Reaction Time
PubMed: 35022327
DOI: 10.1523/JNEUROSCI.0668-21.2021 -
Nature Neuroscience Mar 2015Decades of experimental work have established an imbalance of excitation and inhibition as the leading mechanism of the transition from normal brain function to seizure.... (Review)
Review
Decades of experimental work have established an imbalance of excitation and inhibition as the leading mechanism of the transition from normal brain function to seizure. In epilepsy, these transitions are rare and abrupt. Transition processes incorporating positive feedback, such as activity-dependent disinhibition, could provide these uncommon timing features. A rapidly expanding array of genetic etiologies will help delineate the molecular mechanism(s). This delineation will entail quite a bit of cell biology. The genes discovered so far are more remarkable for their diversity than their similarities.
Topics: Animals; Brain; Epilepsy; Humans; Neural Inhibition; Seizures
PubMed: 25710839
DOI: 10.1038/nn.3947 -
Neuron Oct 2011Cortical processing reflects the interplay of synaptic excitation and synaptic inhibition. Rapidly accumulating evidence is highlighting the crucial role of inhibition... (Review)
Review
Cortical processing reflects the interplay of synaptic excitation and synaptic inhibition. Rapidly accumulating evidence is highlighting the crucial role of inhibition in shaping spontaneous and sensory-evoked cortical activity and thus underscores how a better knowledge of inhibitory circuits is necessary for our understanding of cortical function. We discuss current views of how inhibition regulates the function of cortical neurons and point to a number of important open questions.
Topics: Animals; Cerebral Cortex; Membrane Potentials; Nerve Net; Neural Inhibition; Neurons; Synaptic Transmission
PubMed: 22017986
DOI: 10.1016/j.neuron.2011.09.027 -
Current Opinion in Neurobiology Oct 2017Inhibitory and excitatory neurons form intricate interconnected circuits in the mammalian sensory cortex. Whereas the function of excitatory neurons is largely to... (Review)
Review
Inhibitory and excitatory neurons form intricate interconnected circuits in the mammalian sensory cortex. Whereas the function of excitatory neurons is largely to integrate and transmit information within and between brain areas, inhibitory neurons are thought to shape the way excitatory neurons integrate information, and they exhibit context-specific and behavior-specific responses. Over the last few years, work across sensory modalities has begun unraveling the function of distinct types of cortical inhibitory neurons in sensory processing, identifying their contribution to controlling stimulus selectivity of excitatory neurons and modulating information processing based on the behavioral state of the subject. Here, we review results from recent studies and discuss the implications for the contribution of inhibition to cortical circuit activity and information processing.
Topics: Animals; Humans; Interneurons; Neural Inhibition; Neural Pathways; Sensation; Sensorimotor Cortex
PubMed: 28938181
DOI: 10.1016/j.conb.2017.08.018