scholarly journals Distinct Regulation of History-dependent Responses by Two Cortical Interneuron Populations

2017 ◽  
Author(s):  
Elizabeth A.K. Phillips ◽  
Christoph E. Schreiner ◽  
Andrea R. Hasenstaub
Keyword(s):  
Cortical Inhibition ◽  
Spike Frequency Adaptation ◽  
Sensory Adaptation ◽  
Cortical Interneuron ◽  
Cortical Responses ◽  
Rapid Changes ◽  
Sensory Cortices ◽  
Forward Suppression ◽  
Inhibitory Networks

AbstractCortical responses to repeated stimuli are highly dynamic and rapidly adaptive. Such rapid changes are prominent in all sensory cortices, across which many aspects of circuitry are conserved. As an example, in the auditory cortex, preceding sounds can powerfully suppress responses to later, spectrally similar sounds – a phenomenon called forward suppression. Whether cortical inhibitory networks shape such suppression, or whether it is wholly regulated by common mechanisms such as synaptic depression or spike-frequency adaptation, is controversial. Here, we show that optogenetically suppressing somatostatin-positive interneurons reveals facilitation in neurons that are normally forward-suppressed. This is accompanied by a weakening of forward suppression, suggesting that these interneurons regulate the strength of forward interactions. In contrast, inactivating parvalbumin-positive interneurons does not change suppression strength, but does alter its frequency-dependence. These results establish a role of cortical inhibition in forward suppression and link specific aspects of rapid sensory adaptation to genetically distinct interneuron types.

scholarly journals The Fourth IOCDC

CNS Spectrums ◽  
2000 ◽  
Vol 5 (S4) ◽  
pp. 4-4
Author(s):  
Eric Hollander ◽  
Joseph Zohar ◽  
Donatella Marazziti
Keyword(s):  
Obsessive Compulsive Disorder ◽  
Brain Stimulation ◽  
Current Knowledge ◽  
Active Role ◽  
Cortical Inhibition ◽  
Obsessive Compulsive ◽  
Future Directions ◽  
Compulsive Disorder ◽  
Ablative Surgery

The Fourth International Obsessive Compulsive Disorder Conference (IOCDC) was held February 10–12, 2000, on the beautiful island of St. Thomas. The IOCDC is an annual meeting which brings together the world's leading experts in obsessive-compulsive disorder (OCD) and related disorders in a small workshop setting to present recent research advances, discuss gaps in our current knowledge, and plan or international approaches that address these knowledge gaps. The IOCDC meetings have been held on islands on both sides of the Atlantic—Capri, Guadeloupe, Madeira, and now St. Thomas.The International Organizing Committee consists of Eric Hollander, MD (USA), Joseph Zohar, MD (Israel), and Donatella Marazziti, MD (Italy). The proceedings are generously supported by an unrestricted educational grant from Solvay Pharmaceuticals Inc. and Solvay Pharmaceuticals, and we would like to acknowledge the very important contributions of Chantal Vekens and Mary Blangiardo of Solvay. Also, an mportant part of the success of these meetings stems from the very active role of the chairpersons and cochairpersons of the workshops who lead the discussions, who synthesize the future directions and prepare the manuscripts that result from these discussions that appear in this academic supplement.The meeting led off with a state-of-the-art plenary address by Mark George, MD (USA), describing how new methods of brain stimulation are improving research and therapy in OCD and promise to revolutionize neuropsychiatric research and herapy over the next decade. He describes how transcranial magnetic stimulation (TMS) is used to test the circuits in OCD and test electrophysiologic evaluations of cortical inhibition n OCD. Newer techniques that are less invasive than ablative surgery and appear promising in OCD therapy include vagus nerve stimulation and deep brain stimulation.

The role of exploratory mechanisms in evolution

1995 ◽  
Vol 349 (1329) ◽  
pp. 297-297
Keyword(s):  
Dynamic Instability ◽  
Specific Mechanism ◽  
Cellular Mechanisms ◽  
Selection Processes ◽  
Wide Range ◽  
Rapid Changes ◽  
Neuronal Processes ◽  
History Of ◽  
Variation And Selection

Many cellular mechanisms use a process of variation and selection to generate specific patterns. Among these, dynamic instability of microtubules has been shown to employ a specific mechanism to intentionally generate variation. In many systems the growth of neurons or neuronal processes is excessive, the final connections being established by stabilization of functional interactions. When changes in neuronal networks take place, such as in metamorphosis, use is made of the plasticity of neuronal connectivity. In the immune system, specific responses are generated by variation and selection. Processes that explore a wide range of conditions and a wide range of structures can be called exploratory processes. These are very robust and capable of responding to damage, variability in the environment and ontogenic changes in the organisms. Such robustness would be useful for adapting to changes that occur during phylogenetic changes as well. Given the extensive history of extinction and radiation in evolution, it may be supposed that these mechanisms have themselves been selected for their capacity to survive rapid changes in the organism and for their ability to generate cellular variation.

The role of prosody in morphological change: The case of Hebrew bound numerals

2008 ◽  
Vol 20 (1) ◽  
pp. 41-65 ◽  
Author(s):  
Irit Meir
Keyword(s):  
Native Speakers ◽  
Age Groups ◽  
Noun Phrases ◽  
Grammaticality Judgments ◽  
Rapid Changes ◽  
The Feminine ◽  
Modern Hebrew ◽  
State Of Affairs ◽  
The One

AbstractThe morphological system of cardinal numerals in Modern Hebrew is currently undergoing rapid changes, enabling linguists to unravel the forces shaping the change as it takes place. In the free forms, gender marking on numerals is neutralized by collapsing both masculine and feminine forms into one paradigm, the feminine paradigm. In the bound (definite) forms, an opposite direction is attested, in that at least for some numerals, the masculine forms become more prevalent. The study reported here aims to determine whether the factor determining the change is prosodic or functional in nature, by eliciting production and grammaticality judgments of noun phrases containing bound numerals from five different age groups of native speakers. The results suggest that prosody plays a role in shaping the change, as forms with penultimate stress are favored over those with ultimate stress. In addition, processes of production and processes of grammaticality judgments seem to be subject to different kinds of constraints. This state of affairs indicates that the tension between the tendencies toward simplification on the one hand and maximal distinctness on the other occurs at the morphological level as well.

Bursting in Inhibitory Interneuronal Networks: A Role for Gap-Junctional Coupling

1999 ◽  
Vol 81 (3) ◽  
pp. 1274-1283 ◽  
Author(s):  
F. K. Skinner ◽  
L. Zhang ◽  
J. L. Perez Velazquez ◽  
P. L. Carlen
Keyword(s):  
Theoretical Work ◽  
Oscillatory Behavior ◽  
Minimal Network ◽  
Junctional Coupling ◽  
Synchronization Mechanisms ◽  
The Individual ◽  
Gap Junctional ◽  
Gap Junctional Coupling ◽  
Inhibitory Networks

Bursting in inhibitory interneuronal networks: a role for gap-junctional coupling. Much work now emphasizes the concept that interneuronal networks play critical roles in generating synchronized, oscillatory behavior. Experimental work has shown that functional inhibitory networks alone can produce synchronized activity, and theoretical work has demonstrated how synchrony could occur in mutually inhibitory networks. Even though gap junctions are known to exist between interneurons, their role is far from clear. We present a mechanism by which synchronized bursting can be produced in a minimal network of mutually inhibitory and gap-junctionally coupled neurons. The bursting relies on the presence of persistent sodium and slowly inactivating potassium currents in the individual neurons. Both GABAA inhibitory currents and gap-junctional coupling are required for stable bursting behavior to be obtained. Typically, the role of gap-junctional coupling is focused on synchronization mechanisms. However, these results suggest that a possible role of gap-junctional coupling may lie in the generation and stabilization of bursting oscillatory behavior.

scholarly journals Rapid, Experience-Related Changes in the Organization of Children’s Semantic Knowledge

2018 ◽  
Author(s):  
Layla Unger ◽  
Anna Fisher
Keyword(s):  
Learning Experiences ◽  
Semantic Knowledge ◽  
Knowledge Organization ◽  
Control School ◽  
School Based ◽  
Naturally Occurring ◽  
Rapid Changes ◽  
Taxonomic Organization ◽  
Post Test

The organization of knowledge according to relations between concepts is crucially important for many cognitive processes, and its emergence during childhood is a key focus of cognitive development research. Prior evidence about the role of learning and experience in the development of knowledge organization primarily comes from studies investigating naturally-occurring group differenes (such as children from rural vs. ubran settings, or children who own a pet vs. children who don’t). However, we know little about whether knowledge organization can be relatively rapidly molded by shorter-term learning experiences (e.g., on a time-scale of days vs. months and years). The present study investigated whether learning experiences can drive rapid, measurable changes in knowledge organization in children by investigating the effects of a week-long Zoo summer camp (compared to a control school-based camp) on the degree to which 4- to 9-year-old children’s knowledge about animals was organized according to taxonomic relations. Although there were no differences in taxonomic organization between the Zoo and the school-based camp at pre-test, only children who participated in the Zoo camp showed increases in taxonomic organization at post-test. These findings provide novel evidence that experiences can drive rapid changes in knowledge organization.

scholarly journals RHBDL4 protects against endoplasmic reticulum stress by regulating the morphology and distribution of ER sheets

2021 ◽  
Author(s):  
Viorica Liebe Lastun ◽  
Matthew Freeman
Keyword(s):  
Cell Cycle ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Er Stress ◽  
Liver Steatosis ◽  
Physiological Role ◽  
Cell Types ◽  
Rhomboid Protease ◽  
Rapid Changes

In metazoans, the architecture of the endoplasmic reticulum (ER) differs between cell types, and undergoes major changes through the cell cycle and according to physiological needs. Although much is known about how the different ER morphologies are generated and maintained, especially the ER tubules, how context dependent changes in ER shape and distribution are regulated and the factors involved are less characterized. Here, we show that RHBDL4, an ER-resident rhomboid protease, modulates the shape and distribution of the ER, especially under conditions that require rapid changes in the ER sheet distribution, including ER stress. RHBDL4 interacts with CLIMP-63, a protein involved in ER sheet stabilisation, and with the cytoskeleton. Mice lacking RHBDL4 are sensitive to ER stress and develop liver steatosis, a phenotype associated with unresolved ER stress. Our data introduce a new physiological role of RHBDL4 and also imply that this function does not require its enzymatic activity.

scholarly journals Rapid, Experience-Related Changes in the Organization of Children’s Semantic Knowledge

2019 ◽  
Author(s):  
Layla Unger ◽  
Anna Fisher
Keyword(s):  
Learning Experiences ◽  
Semantic Knowledge ◽  
Knowledge Organization ◽  
Control School ◽  
School Based ◽  
Naturally Occurring ◽  
Rapid Changes ◽  
Taxonomic Organization ◽  
Post Test

The organization of knowledge according to relations between concepts is crucially important for many cognitive processes, and its emergence during childhood is a key focus of cognitive development research. Prior evidence about the role of learning and experience in the development of knowledge organization primarily comes from studies investigating naturally-occurring group differenes (such as children from rural vs. ubran settings, or children who own a pet vs. children who don’t). However, we know little about whether knowledge organization can be relatively rapidly molded by shorter-term learning experiences (e.g., on a time-scale of days vs. months and years). The present study investigated whether learning experiences can drive rapid, measurable changes in knowledge organization in children by investigating the effects of a week-long Zoo summer camp (compared to a control school-based camp) on the degree to which 4- to 9-year-old children’s knowledge about animals was organized according to taxonomic relations. Although there were no differences in taxonomic organization between the Zoo and the school-based camp at pre-test, only children who participated in the Zoo camp showed increases in taxonomic organization at post-test. These findings provide novel evidence that experiences can drive rapid changes in knowledge organization.

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