scholarly journals Activity-dependent synaptic integration and modulation of bilateral excitatory inputs in an auditory coincidence detection circuit

2018 ◽  
Vol 596 (10) ◽  
pp. 1981-1997 ◽  
Author(s):  
Yong Lu ◽  
Yuwei Liu ◽  
Rebecca J. Curry
Keyword(s):  
Coincidence Detection ◽  
Synaptic Integration ◽  
Detection Circuit ◽  
Activity Dependent

scholarly journals Corticospinal-specific HCN expression in mouse motor cortex: Ih-dependent synaptic integration as a candidate microcircuit mechanism involved in motor control

2011 ◽  
Vol 106 (5) ◽  
pp. 2216-2231 ◽  
Author(s):  
Patrick L. Sheets ◽  
Benjamin A. Suter ◽  
Taro Kiritani ◽  
C. Savio Chan ◽  
D. James Surmeier ◽  
...  
Keyword(s):  
Motor Control ◽  
Motor Cortex ◽  
Pyramidal Neurons ◽  
Action Planning ◽  
Coincidence Detection ◽  
Synaptic Integration ◽  
Mrna Levels ◽  
Adrenergic Stimulation ◽  
Action Execution ◽  
Layer 2

Motor cortex is a key brain center involved in motor control in rodents and other mammals, but specific intracortical mechanisms at the microcircuit level are largely unknown. Neuronal expression of hyperpolarization-activated current ( Ih) is cell class specific throughout the nervous system, but in neocortex, where pyramidal neurons are classified in various ways, a systematic pattern of expression has not been identified. We tested whether Ih is differentially expressed among projection classes of pyramidal neurons in mouse motor cortex. Ih expression was high in corticospinal neurons and low in corticostriatal and corticocortical neurons, a pattern mirrored by mRNA levels for HCN1 and Trip8b subunits. Optical mapping experiments showed that Ih attenuated glutamatergic responses evoked across the apical and basal dendritic arbors of corticospinal but not corticostriatal neurons. Due to Ih, corticospinal neurons resonated, with a broad peak at ∼4 Hz, and were selectively modulated by α-adrenergic stimulation. Ih reduced the summation of short trains of artificial excitatory postsynaptic potentials (EPSPs) injected at the soma, and similar effects were observed for short trains of actual EPSPs evoked from layer 2/3 neurons. Ih narrowed the coincidence detection window for EPSPs arriving from separate layer 2/3 inputs, indicating that the dampening effect of Ih extended to spatially disperse inputs. To test the role of corticospinal Ih in transforming EPSPs into action potentials, we transfected layer 2/3 pyramidal neurons with channelrhodopsin-2 and used rapid photostimulation across multiple sites to synaptically drive spiking activity in postsynaptic neurons. Blocking Ih increased layer 2/3-driven spiking in corticospinal but not corticostriatal neurons. Our results imply that Ih-dependent synaptic integration in corticospinal neurons constitutes an intracortical control mechanism, regulating the efficacy with which local activity in motor cortex is transferred to downstream circuits in the spinal cord. We speculate that modulation of Ih in corticospinal neurons could provide a microcircuit-level mechanism involved in translating action planning into action execution.

scholarly journals Siah2 integrates mitogenic and extracellular matrix signals linking neuronal progenitor ciliogenesis with germinal zone occupancy

2019 ◽  
Author(s):  
Taren Ong ◽  
Niraj Trivedi ◽  
Randall Wakefield ◽  
Sharon Frase ◽  
David J. Solecki
Keyword(s):  
Extracellular Matrix ◽  
Primary Cilia ◽  
Mapk Signaling ◽  
Coincidence Detection ◽  
Dependent Manner ◽  
Neuronal Progenitor ◽  
Germinal Zone ◽  
Detection Circuit ◽  
Proliferation And Differentiation ◽  
Developing Neurons

Evidence is lacking as to how developing neurons integrate mitogenic signals with microenvironment cues to control proliferation and differentiation. We determined that the Siah2 E3 ubiquitin ligase functions in a coincidence detection circuit linking responses to the Shh mitogen and the extracellular matrix to control cerebellar granule neurons (CGN) germinal zone (GZ) occupancy. We found that Shh maintains Siah2 expression in CGN progenitors (GNPs) in a Ras/Mapk-dependent manner. Siah2 supports ciliogenesis in a feed-forward fashion by restraining ciliogenic targets. Efforts to identify GZ sources of Ras/Mapk signaling led us to discover that GNPs respond to laminin, but not vitronectin, in the microenvironment via integrin β1 receptors, which engages the Ras/Mapk cascade, and that this niche interaction is essential for promoting GNP ciliogenesis. As GNPs leave the GZ, differentiation is seamlessly driven by changing extracellular cues that diminish Siah2-activity leading to primary cilia retraction and attenuation of mitogenic responses.

Crayfish Escape

2017 ◽  
Author(s):  
Donald Edwards
Keyword(s):  
Decision Making ◽  
Synaptic Plasticity ◽  
Social Status ◽  
Neural Control ◽  
Neural Circuitry ◽  
Coincidence Detection ◽  
Synaptic Integration ◽  
Decapod Crustaceans ◽  
Electrical Synapses ◽  
Different Types

Crayfish are decapod crustaceans that use different forms of escape to flee from different types of predatory attacks. Lateral and Medial Giant escapes are released by giant interneurons of the same name in response to sudden, sharp attacks from the rear and front of the animal, respectively. A Lateral Giant (LG) escape uses a fast rostral abdominal flexion to pitch the animal up and forward at very short latency. It is succeeded by guided swimming movements powered by a series of rapid abdominal flexions and extensions. A Medial Giant (MG) escape uses a fast, full abdominal flexion to thrust the animal directly backward, and is also followed by swimming that moves the animal rapidly away from the attacker. More slowly developing attacks evoke Non-Giant (NG) escapes, which have a longer latency, are varied in the form of abdominal flexion, and are directed initially away from the attacker. They, too, are followed by swimming away from the attacker. The neural circuitry for LG escape has been extensively studied and has provided insights into the neural control of behavior, synaptic integration, coincidence detection, electrical synapses, behavioral and synaptic plasticity, neuroeconomical decision-making, and the modulatory effects of monoamines and of changes in the animal’s social status.

scholarly journals Dendritic computations captured by an effective point neuron model

2019 ◽  
Vol 116 (30) ◽  
pp. 15244-15252 ◽  
Author(s):  
Songting Li ◽  
Nan Liu ◽  
Xiaohui Zhang ◽  
David W. McLaughlin ◽  
Douglas Zhou ◽  
...  
Keyword(s):  
Neuron Model ◽  
Direction Selectivity ◽  
Neuronal Morphology ◽  
Coincidence Detection ◽  
Synaptic Integration ◽  
Dimensional Structure ◽  
Synaptic Currents ◽  
Integration Rule ◽  
Dendritic Integration ◽  
Synaptic Inputs

Complex dendrites in general present formidable challenges to understanding neuronal information processing. To circumvent the difficulty, a prevalent viewpoint simplifies the neuronal morphology as a point representing the soma, and the excitatory and inhibitory synaptic currents originated from the dendrites are treated as linearly summed at the soma. Despite its extensive applications, the validity of the synaptic current description remains unclear, and the existing point neuron framework fails to characterize the spatiotemporal aspects of dendritic integration supporting specific computations. Using electrophysiological experiments, realistic neuronal simulations, and theoretical analyses, we demonstrate that the traditional assumption of linear summation of synaptic currents is oversimplified and underestimates the inhibition effect. We then derive a form of synaptic integration current within the point neuron framework to capture dendritic effects. In the derived form, the interaction between each pair of synaptic inputs on the dendrites can be reliably parameterized by a single coefficient, suggesting the inherent low-dimensional structure of dendritic integration. We further generalize the form of synaptic integration current to capture the spatiotemporal interactions among multiple synaptic inputs and show that a point neuron model with the synaptic integration current incorporated possesses the computational ability of a spatial neuron with dendrites, including direction selectivity, coincidence detection, logical operation, and a bilinear dendritic integration rule discovered in experiment. Our work amends the modeling of synaptic inputs and improves the computational power of a modeling neuron within the point neuron framework.

scholarly journals Siah2 integrates mitogenic and extracellular matrix signals linking neuronal progenitor ciliogenesis with germinal zone occupancy

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Taren Ong ◽  
Niraj Trivedi ◽  
Randall Wakefield ◽  
Sharon Frase ◽  
David J. Solecki
Keyword(s):  
Extracellular Matrix ◽  
Primary Cilia ◽  
Mapk Signaling ◽  
Coincidence Detection ◽  
Dependent Manner ◽  
Neuronal Progenitor ◽  
Germinal Zone ◽  
Detection Circuit ◽  
Proliferation And Differentiation ◽  
Developing Neurons

Abstract Evidence is lacking as to how developing neurons integrate mitogenic signals with microenvironment cues to control proliferation and differentiation. We determine that the Siah2 E3 ubiquitin ligase functions in a coincidence detection circuit linking responses to the Shh mitogen and the extracellular matrix to control cerebellar granule neurons (CGN) GZ occupancy. We show that Shh signaling maintains Siah2 expression in CGN progenitors (GNPs) in a Ras/Mapk-dependent manner. Siah2 supports ciliogenesis in a feed-forward fashion by restraining cilium disassembly. Efforts to identify sources of the Ras/Mapk signaling led us to discover that GNPs respond to laminin, but not vitronectin, in the GZ microenvironment via integrin β1 receptors, which engages the Ras/Mapk cascade with Shh, and that this niche interaction is essential for promoting GNP ciliogenesis. As GNPs leave the GZ, differentiation is driven by changing extracellular cues that diminish Siah2-activity leading to primary cilia shortening and attenuation of the mitogenic response.

scholarly journals Control of a Depolarizing GABAergic Input in an Auditory Coincidence Detection Circuit

2009 ◽  
Vol 102 (3) ◽  
pp. 1672-1683 ◽  
Author(s):  
Zheng-Quan Tang ◽  
Hongxiang Gao ◽  
Yong Lu
Keyword(s):  
Inhibitory Action ◽  
Metabotropic Glutamate Receptor ◽  
Phase Locking ◽  
Reversal Potential ◽  
Coincidence Detection ◽  
Third Order ◽  
Interaural Time Differences ◽  
Metabotropic Glutamate ◽  
Detection Circuit ◽  
Excitatory Action

Neurons in the chicken nucleus laminaris (NL), the third-order auditory neurons that detect the interaural time differences that enable animals to localize sounds in the horizontal plane, receive glutamatergic excitation from the cochlear nucleus magnocellularis (NM) and GABAergic inhibition from the ipsilateral superior olivary nucleus. Here, we study metabotropic glutamate receptor (mGluR)- and GABAB receptor (GABABR)-mediated modulation of synaptic transmission in NL neurons. Gramicidin-perforated recordings from acute brain stem slice preparations showed that the reversal potential of the GABAergic responses in NL neurons was more depolarized than the spike threshold. Activation of the GABAergic input produced a mix of inhibitory and excitatory actions in NL neurons. The inhibitory action is known to be critical in improving the acuity of temporal processing of sounds. The excitatory action, however, would reduce the phase locking fidelity of NL neurons in response to their excitatory inputs from the NM. We show that activation of presynaptic mGluRs or GABABRs by either exogenous agonists or synaptically released neurotransmitters reduced the GABAergic responses, preventing the excitatory action of GABA while leaving the inhibitory action intact. Unlike most CNS synapses, the glutamatergic transmission in the NL was not modulated by either mGluRs or GABABRs, indicating that fixed (nonmodulatory) excitatory inputs to the NL may be optimal for coincidence detection. This study contributes to our understanding of how selective neuromodulation is achieved to suit a particular function of neuronal circuits in the brain.

Malfunctional Reorganization in the Developing Limbo-Prefrontal System in Animals: Implications for Human Psychoses?

2001 ◽  
Vol 12 (1) ◽  
pp. 8-14
Author(s):  
Gertraud Teuchert-Noodt ◽  
Ralf R. Dawirs
Keyword(s):  
Prefrontal Cortex ◽  
Mental Disorders ◽  
Dentate Gyrus ◽  
Cognitive Functions ◽  
Experimental Approach ◽  
Regulatory Mechanisms ◽  
Hippocampal Dentate Gyrus ◽  
Non Invasive ◽  
Invasive Method ◽  
Activity Dependent

Abstract: Neuroplasticity research in connection with mental disorders has recently bridged the gap between basic neurobiology and applied neuropsychology. A non-invasive method in the gerbil (Meriones unguiculus) - the restricted versus enriched breading and the systemically applied single methamphetamine dose - offers an experimental approach to investigate psychoses. Acts of intervening affirm an activity dependent malfunctional reorganization in the prefrontal cortex and in the hippocampal dentate gyrus and reveal the dopamine position as being critical for the disruption of interactions between the areas concerned. From the extent of plasticity effects the probability and risk of psycho-cognitive development may be derived. Advance may be expected from insights into regulatory mechanisms of neurogenesis in the hippocampal dentate gyrus which is obviously to meet the necessary requirements to promote psycho-cognitive functions/malfunctions via the limbo-prefrontal circuit.

Compartment-resolved imaging of activity dependent dynamics of cortical blood volume and oximetry

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S681-S681 ◽  
Author(s):  
Amiram Grinvald ◽  
Rina Hildesheim ◽  
Ivo Vanzetta
Keyword(s):  
Blood Volume ◽  
Activity Dependent
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