scholarly journals Understanding Emotions: Origins and Roles of the Amygdala

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 823
Author(s):  
Goran Šimić ◽  
Mladenka Tkalčić ◽  
Vana Vukić ◽  
Damir Mulc ◽  
Ena Španić ◽  
...  
Keyword(s):  
Sensory Information ◽  
Anterior Cingulate ◽  
Central Nucleus ◽  
Subcortical Structures ◽  
Neuronal Populations ◽  
Efferent Projections ◽  
Short And Long Term ◽  
Understanding Emotions ◽  
Fight Or Flight Response ◽  
And Behavior

Emotions arise from activations of specialized neuronal populations in several parts of the cerebral cortex, notably the anterior cingulate, insula, ventromedial prefrontal, and subcortical structures, such as the amygdala, ventral striatum, putamen, caudate nucleus, and ventral tegmental area. Feelings are conscious, emotional experiences of these activations that contribute to neuronal networks mediating thoughts, language, and behavior, thus enhancing the ability to predict, learn, and reappraise stimuli and situations in the environment based on previous experiences. Contemporary theories of emotion converge around the key role of the amygdala as the central subcortical emotional brain structure that constantly evaluates and integrates a variety of sensory information from the surroundings and assigns them appropriate values of emotional dimensions, such as valence, intensity, and approachability. The amygdala participates in the regulation of autonomic and endocrine functions, decision-making and adaptations of instinctive and motivational behaviors to changes in the environment through implicit associative learning, changes in short- and long-term synaptic plasticity, and activation of the fight-or-flight response via efferent projections from its central nucleus to cortical and subcortical structures.

A Review of the Restorative Environment Research in the Mainland of China

2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Meng Ruoxi ◽  
Xu Leiqing
Keyword(s):  
Subjective Evaluation ◽  
Publishing House ◽  
Mainland China ◽  
Research Field ◽  
Restorative Environment ◽  
International Publishing ◽  
Fight Or Flight Response ◽  
And Behavior ◽  
Objective Indicators ◽  
Theory Framework

More and more Chinese experts focus on the research field of the restorative environment and public health. We reorganized the theories of restorative environment and proposed a theory framework which consists of Attention Restorative Theory(ART) and psycho-evolutionary theory and other three auxiliary hypothesis included Biophilia Theory, Prospect-Refuge Theory and Stress: The "fight or flight" response We classified the experiments methods into three types; the psychological, subjective evaluation, physiological objective indicators, and  behavior improvements .We could figure out some shared questions at the current research in mainland China, such as limited research methods, limited senses used in the current research.© 2016.The Authors. Published for AMER ABRA by e-International Publishing House, Ltd., UK. Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies, Faculty of Architecture, Planning & Surveying, UniversitiTeknologi MARA, Malaysia.Keywords : Restorative; Theory;Questionnaire;Experiments 

scholarly journals Population Coding of Self-Motion: Applying Bayesian Analysis to a Population of Visual Interneurons in the Fly

2005 ◽  
Vol 94 (3) ◽  
pp. 2182-2194 ◽  
Author(s):  
Katja Karmeier ◽  
Holger G. Krapp ◽  
Martin Egelhaaf
Keyword(s):  
Bayesian Analysis ◽  
Rotation Axis ◽  
Sensory Information ◽  
Population Coding ◽  
Calliphora Vicina ◽  
Integration Time ◽  
Noise Correlation ◽  
Neuronal Populations ◽  
Response Onset ◽  
Self Motion

Coding of sensory information often involves the activity of neuronal populations. We demonstrate how the accuracy of a population code depends on integration time, the size of the population, and noise correlation between the participating neurons. The population we study consists of 10 identified visual interneurons in the blowfly Calliphora vicina involved in optic flow processing. These neurons are assumed to encode the animal's head or body rotations around horizontal axes by means of graded potential changes. From electrophysiological experiments we obtain parameters for modeling the neurons' responses. From applying a Bayesian analysis on the modeled population response we draw three major conclusions. First, integration of neuronal activities over a time period of only 5 ms after response onset is sufficient to decode accurately the rotation axis. Second, noise correlation between neurons has only little impact on the population's performance. And third, although a population of only two neurons would be sufficient to encode any horizontal rotation axis, the population of 10 vertical system neurons is advantageous if the available integration time is short. For the fly, short integration times to decode neuronal responses are important when controlling rapid flight maneuvers.

scholarly journals Refinement of the primate corticospinal pathway during prenatal development

2019 ◽  
Author(s):  
Ana Rita Ribeiro Gomes ◽  
Etienne Olivier ◽  
Herbert P. Killackey ◽  
Pascale Giroud ◽  
Michel Berland ◽  
...  
Keyword(s):  
Occipital Cortex ◽  
Prenatal Development ◽  
Zona Incerta ◽  
Central Nucleus ◽  
Projection Neurons ◽  
Subcortical Structures ◽  
Corticospinal Pathway ◽  
Contralateral Projection ◽  
Order Of Magnitude ◽  
Ipsilateral Projection

AbstractPerturbation of the developmental refinement of the corticospinal pathway leads to motor disorders. In non-primates developmental refinement is well documented, however in primates invasive investigations of the developing corticospinal pathway have been confined to neonatal and postnatal stages when refinement is relatively modest.Here, we investigated the developmental changes in the distribution of corticospinal projection neurons in cynomolgus monkey. Injections of retrograde tracer at the cervical levels of the spinal cord at embryonic day (E) 95 and E105 show that (i) areal distribution of back-labeled neurons is more extensive than in the neonate and dense labeling is found in prefrontal, limbic, temporal and occipital cortex; (ii) distributions of contra- and ipsilateral projecting corticospinal neurons are comparable in terms of location and numbers of labeled neurons, in contrast to the adult where the contralateral projection is an order of magnitude higher than the ipsilateral projection. Findings from one largely restricted injection suggest a hitherto unsuspected early innervation of the gray matter.In the fetus there was in addition dense labeling in the central nucleus of the amygdala, the hypothalamus, the subthalamic nucleus and the adjacent region of the zona incerta, subcortical structures with only minor projections in the adult control.

scholarly journals Individualized non-invasive brain stimulation engages the subgenual anterior cingulate and amygdala

2018 ◽  
Author(s):  
Desmond J Oathes ◽  
Jared Zimmerman ◽  
Romain Duprat ◽  
Seda Cavdaroglu ◽  
Morgan Scully ◽  
...  
Keyword(s):  
Brain Stimulation ◽  
Brain Networks ◽  
Brain Network ◽  
Anterior Cingulate ◽  
Clinical Effects ◽  
Brain Response ◽  
Subcortical Structures ◽  
Non Invasive ◽  
Individual Participant ◽  
Communication Flow

Brain stimulation is used clinically to treat a variety of neurological and psychiatric conditions. The mechanisms of the clinical effects of these brain-based therapies are presumably dependent on their effects on brain networks. It has been hypothesized that using individualized brain network maps is an optimal strategy for defining network boundaries and topologies. Traditional non-invasive imaging can determine correlations between structural or functional time series. However, they cannot easily establish hierarchies in communication flow as done in non-human animals using invasive methods. In the present study, we interleaved functional MRI recordings with non-invasive transcranial magnetic stimulation in the attempt to map causal communication between the prefrontal cortex and two subcortical structures thought to contribute to affective dysregulation: the subgenual anterior cingulate cortex (sgACC) and the amygdala. In both cases, we found evidence that these brain areas were engaged when TMS was applied to prefrontal sites determined from each participant's previous fMRI scan. Specifically, after transforming individual participant images to within-scan quantiles of evoked TMS response, we modeled the average quantile response within a given region across stimulation sites and individuals to demonstrate that the targets were differentially influenced by TMS. Furthermore, we found that the sgACC distributed brain network, estimated in a separate cohort, was engaged in response to sgACC focused TMS and was partially separable from the proximal default mode network response. The amygdala, but not its distributed network, responded to TMS. Our findings indicate that individual targeting and brain response measurements usefully capture causal circuit mapping to the sgACC and amygdala in humans, setting the stage for approaches to non-invasively modulate subcortical nodes of distributed brain networks in clinical interventions and mechanistic human neuroscience studies.

scholarly journals Perinatal fentanyl exposure leads to long-lasting impairments in somatosensory circuit function and behavior

2020 ◽  
Author(s):  
Jason Alipio ◽  
Catherine Haga ◽  
Megan E Fox ◽  
Keiko Arakawa ◽  
Rakshita Balaji ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Morphological Changes ◽  
Anterior Cingulate ◽  
Preclinical Model ◽  
Sensory Stimuli ◽  
Synaptic Excitation ◽  
Molecular Abnormalities ◽  
Postsynaptic Currents ◽  
And Behavior

One consequence of the opioid epidemic are lasting neurodevelopmental sequelae afflicting adolescents exposed to opioids in the womb. A translationally relevant and developmentally accurate preclinical model is needed to understand the behavioral, circuit, network, and molecular abnormalities resulting from this exposure. By employing a novel preclinical model of perinatal fentanyl exposure, our data reveal that fentanyl has several dose-dependent, developmental consequences to somatosensory function and behavior. Newborn male and female mice exhibit signs of withdrawal and sensory-related deficits that extend at least to adolescence. As fentanyl exposure does not affect dams' health or maternal behavior, these effects result from the direct actions of perinatal fentanyl on the pups' developing brain. At adolescence, exposed mice exhibit reduced adaptation to sensory stimuli, and a corresponding impairment in primary somatosensory (S1) function. In vitro electrophysiology demonstrates a long-lasting reduction in S1 synaptic excitation, evidenced by decreases in release probability, NMDA receptor-mediated postsynaptic currents, and frequency of miniature excitatory postsynaptic currents, as well as increased frequency of miniature inhibitory postsynaptic currents. In contrast, anterior cingulate cortical neurons exhibit an opposite phenotype, with increased synaptic excitation. Consistent with these changes, electrocorticograms reveal suppressed ketamine-evoked γ oscillations. Morphological analysis of S1 pyramidal neurons indicate reduced dendritic complexity, dendritic length, and soma size. Further, exposed mice exhibited abnormal cortical mRNA expression of key receptors and neuronal growth and development, changes that were consistent with the electrophysiological and morphological changes. These findings demonstrate the lasting sequelae of perinatal fentanyl exposure on sensory processing and function.

scholarly journals Perceptual detection depends on spike count integration

2019 ◽  
Author(s):  
Jackson J. Cone ◽  
Morgan L. Bade ◽  
Nicolas Y. Masse ◽  
Elizabeth A. Page ◽  
David J. Freedman ◽  
...  
Keyword(s):  
Neural Networks ◽  
Cerebral Cortex ◽  
Visual Cortex ◽  
Recurrent Neural Networks ◽  
Neural Circuit ◽  
Visual Detection ◽  
Spike Count ◽  
Neuronal Responses ◽  
Neuronal Populations ◽  
And Behavior

AbstractWhenever the retinal image changes some neurons in visual cortex increase their rate of firing, while others decrease their rate of firing. Linking specific sets of neuronal responses with perception and behavior is essential for understanding mechanisms of neural circuit computation. We trained mice to perform visual detection tasks and used optogenetic perturbations to increase or decrease neuronal spiking primary visual cortex (V1). Perceptual reports were always enhanced by increments in V1 spike counts and impaired by decrements, even when increments and decrements were delivered to the same neuronal populations. Moreover, detecting changes in cortical activity depended on spike count integration rather than instantaneous changes in spiking. Recurrent neural networks trained in the task similarly relied on increments in neuronal activity when activity was costly. This work clarifies neuronal decoding strategies employed by cerebral cortex to translate cortical spiking into percepts that can be used to guide behavior.

scholarly journals Selective enhancement of object representations through multisensory integration

2019 ◽  
Author(s):  
David A. Tovar ◽  
Micah M. Murray ◽  
Mark T. Wallace
Keyword(s):  
Multisensory Integration ◽  
Sensory Information ◽  
Stimulus Presentation ◽  
Building Blocks ◽  
Object Representations ◽  
The Individual ◽  
And Behavior ◽  
Living Objects ◽  
Selective Enhancement ◽  
The Brain

AbstractObjects are the fundamental building blocks of how we create a representation of the external world. One major distinction amongst objects is between those that are animate versus inanimate. Many objects are specified by more than a single sense, yet the nature by which multisensory objects are represented by the brain remains poorly understood. Using representational similarity analysis of human EEG signals, we show enhanced encoding of audiovisual objects when compared to their corresponding visual and auditory objects. Surprisingly, we discovered the often-found processing advantages for animate objects was not evident in a multisensory context due to greater neural enhancement of inanimate objects—the more weakly encoded objects under unisensory conditions. Further analysis showed that the selective enhancement of inanimate audiovisual objects corresponded with an increase in shared representations across brain areas, suggesting that neural enhancement was mediated by multisensory integration. Moreover, a distance-to-bound analysis provided critical links between neural findings and behavior. Improvements in neural decoding at the individual exemplar level for audiovisual inanimate objects predicted reaction time differences between multisensory and unisensory presentations during a go/no-go animate categorization task. Interestingly, links between neural activity and behavioral measures were most prominent 100 to 200ms and 350 to 500ms after stimulus presentation, corresponding to time periods associated with sensory evidence accumulation and decision-making, respectively. Collectively, these findings provide key insights into a fundamental process the brain uses to maximize information it captures across sensory systems to perform object recognition.Significance StatementOur world is filled with an ever-changing milieu of sensory information that we are able to seamlessly transform into meaningful perceptual experience. We accomplish this feat by combining different features from our senses to construct objects. However, despite the fact that our senses do not work in isolation but rather in concert with each other, little is known about how the brain combines the senses together to form object representations. Here, we used EEG and machine learning to study how the brain processes auditory, visual, and audiovisual objects. Surprisingly, we found that non-living objects, the objects which were more difficult to process with one sense alone, benefited the most from engaging multiple senses.

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