scholarly journals Contribution of AMPA and NMDA receptors in the spontaneous firing patterns of single neurons in autaptic culture

Biosystems ◽  
2020 ◽  
Vol 198 ◽  
pp. 104278
Author(s):  
Kouhei Hattori ◽  
Takeshi Hayakawa ◽  
Akira Nakanishi ◽  
Mihoko Ishida ◽  
Hideaki Yamamoto ◽  
...  
Keyword(s):  
Nmda Receptors ◽  
Spontaneous Firing ◽  
Single Neurons ◽  
Firing Patterns ◽  
Ampa And Nmda Receptors

scholarly journals Aberrant development of excitatory circuits to inhibitory neurons in the primary visual cortex after neonatal binocular enucleation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rongkang Deng ◽  
Joseph P. Y. Kao ◽  
Patrick O. Kanold
Keyword(s):  
Visual Cortex ◽  
Nmda Receptors ◽  
Laser Scanning ◽  
Inhibitory Neurons ◽  
Gabaergic Interneurons ◽  
Cortical Circuits ◽  
Retinal Input ◽  
Layer 4 ◽  
Ampa And Nmda Receptors ◽  
Laser Scanning Photostimulation

AbstractThe development of GABAergic interneurons is important for the functional maturation of cortical circuits. After migrating into the cortex, GABAergic interneurons start to receive glutamatergic connections from cortical excitatory neurons and thus gradually become integrated into cortical circuits. These glutamatergic connections are mediated by glutamate receptors including AMPA and NMDA receptors and the ratio of AMPA to NMDA receptors decreases during development. Since previous studies have shown that retinal input can regulate the early development of connections along the visual pathway, we investigated if the maturation of glutamatergic inputs to GABAergic interneurons in the visual cortex requires retinal input. We mapped the spatial pattern of glutamatergic connections to layer 4 (L4) GABAergic interneurons in mouse visual cortex at around postnatal day (P) 16 by laser-scanning photostimulation and investigated the effect of binocular enucleations at P1/P2 on these patterns. Gad2-positive interneurons in enucleated animals showed an increased fraction of AMPAR-mediated input from L2/3 and a decreased fraction of input from L5/6. Parvalbumin-expressing (PV) interneurons showed similar changes in relative connectivity. NMDAR-only input was largely unchanged by enucleation. Our results show that retinal input sculpts the integration of interneurons into V1 circuits and suggest that the development of AMPAR- and NMDAR-only connections might be regulated differently.

Intrinsic Firing Patterns and Whisker-Evoked Synaptic Responses of Neurons in the Rat Barrel Cortex

1999 ◽  
Vol 81 (3) ◽  
pp. 1171-1183 ◽  
Author(s):  
J. Julius Zhu ◽  
Barry W. Connors
Keyword(s):  
Action Potentials ◽  
Barrel Cortex ◽  
Cell Types ◽  
Field Size ◽  
Evoked Responses ◽  
Single Neurons ◽  
Firing Patterns ◽  
Complex Spike ◽  
Intrinsic Firing ◽  
Synaptic Responses

Intrinsic firing patterns and whisker-evoked synaptic responses of neurons in the rat barrel cortex. We have used whole cell recording in the anesthetized rat to study whisker-evoked synaptic and spiking responses of single neurons in the barrel cortex. On the basis of their intrinsic firing patterns, neurons could be classified as either regular-spiking (RS) cells, intrinsically burst-spiking (IB) cells, or fast-spiking (FS) cells. Some recordings responded to current injection with a complex spike pattern characteristic of apical dendrites. All cell types had high rates of spontaneous postsynaptic potentials, both excitatory (EPSPs) and inhibitory (IPSPs). Some spontaneous EPSPs reached threshold, and these typically elicited only single action potentials in RS cells, bursts of action potentials in FS cells and IB cells, and a small, fast spike or a complex spike in dendrites. Deflection of single whiskers evoked a fast initial EPSP, a prolonged IPSP, and delayed EPSPs in all cell types. The intrinsic firing pattern of cells predicted their short-latency whisker-evoked spiking patterns. All cell types responded best to one or, occasionally, two primary whiskers, but typically 6–15 surrounding whiskers also generated significant synaptic responses. The initial EPSP had a relatively fixed amplitude and latency, and its amplitude in response to first-order surrounding whiskers was ∼55% of that induced by the primary whisker. Second- and third-order surrounding whiskers evoked responses of ∼27 and 12%, respectively. The latency of the initial EPSP was shortest for the primary whiskers, longer for surrounding whiskers, and varied with the neurons’ depth below the pia. EPSP latency was shortest in the granular layer, longer in supragranular layers, and longest in infragranular layers. The receptive field size, defined as the total number of fast EPSP-inducing whiskers, was independent of each cell’s intrinsic firing type, its subpial depth, or the whisker stimulus parameters. On average, receptive fields included >10 whiskers. Our results show that single neurons integrate rapid synaptic responses from a large proportion of the mystacial vibrissae, and suggest that the whisker-evoked responses of barrel neurons are a function of both synaptic inputs and intrinsic membrane properties.

Information coding in the rodent prefrontal cortex. II. Ensemble activity in orbitofrontal cortex

1995 ◽  
Vol 74 (2) ◽  
pp. 751-762 ◽  
Author(s):  
G. Schoenbaum ◽  
H. Eichenbaum
Keyword(s):  
Orbitofrontal Cortex ◽  
Single Neuron ◽  
Activity Space ◽  
Behavioral Performance ◽  
Single Neurons ◽  
Reward Contingency ◽  
Neuron Firing ◽  
Firing Patterns ◽  
Neural Ensembles ◽  
Odor Discrimination Task

1. Neural activity was recorded from the orbitofrontal cortex (OF) of rats performing an eight-odor discrimination task that included predictable associations between particular odor pairs. A modified linear discriminant analysis was employed to characterize the population response in each trial of the task as a point in an N-dimensional activity space with the firing rate of each cell in the population represented on one of the N dimensions. The ability of the ensemble to discriminate among conditions of a variable was reflected in the tendency of population responses to cluster together in this activity space for repetitions of a given condition. We assessed coding of several variables describing the period of odor sampling, focusing on aspects of current, past, and future events reflected in single-neuron firing patterns, in ensembles composed of 22-138 cells active during the period when the rats sampled the discriminative stimulus in each trial. 2. OF ensembles performed well at discriminating variables with relevance to task demands represented in single-neuron firing patterns, specifically the physical attributes and assigned reward contingency of the current odor as well as the expectation of reward in the following trial that could be inferred from the predictable associations between particular pairs of odors. OF ensembles were able to correctly identify the identity and assigned reward contingency of the current odor in up to 52% (chance = 12.5%) and 99% (chance = 50%) of all trials, respectively, such that the observed behavioral performance required a population of 5,364 odor-responsive cells in the case of odor identity and only 40 cells in the case of valence. Expectations regarding upcoming rewards based on both assigned response contingency and associations between particular pairs of odors were correctly classified in up to 67% (chance = 20%) of all trials such that the observed level of behavioral performance required a population of 3,169 cells. 3. Other information represented in the single-neuron firing patterns, such as the identity and reward contingency of the preceding odor and specific odor-odor associations, was poorly encoded by OF ensembles. Thus neural ensembles in OF may represent only some of the information reflected in single-neuron activity. Stable coding of only the most useful and relevant information by the ensemble might emerge from the tuning properties of single neurons under the influence of the task at hand, producing in the well-trained animal the observed pattern of broad and diverse coding by single neurons and selective, task-relevant coding by neural ensembles in OF.

scholarly journals Global Dynamics of Intact AMPA and NMDA Receptors using Elastic Network Models

2016 ◽  
Vol 110 (3) ◽  
pp. 382a
Author(s):  
Ji Young Lee ◽  
Anindita Dutta ◽  
James Krieger ◽  
Javier Garcia-Nafria ◽  
Ingo Greger ◽  
...  
Keyword(s):  
Nmda Receptors ◽  
Network Models ◽  
Global Dynamics ◽  
Elastic Network ◽  
Elastic Network Models ◽  
Ampa And Nmda Receptors

COMPUTER SIMULATION OF COTRANSMISSION BY EXCITATORY AMINO ACIDS AND ACETYLCHOLINE IN THE ENTERIC NERVOUS SYSTEM

2007 ◽  
Vol 07 (02) ◽  
pp. 229-246
Author(s):  
ROUSTEM MIFTAHOF ◽  
N. R. AKHMADEEV
Keyword(s):  
Amino Acids ◽  
Nervous System ◽  
Nmda Receptors ◽  
Enteric Nervous System ◽  
Ampa Receptors ◽  
Excitatory Amino Acids ◽  
Electrical Response ◽  
Ampa And Nmda Receptors ◽  
Irritable Bowel

The role of cotransmission by α-amino-3-hydroxy-5-methyl-4-isoxalose propionic acid (AMPA), L-aspartate, N-methyl-D-aspartate (NMDA), and acetylcholine (ACh) as well as the coexpression of AMPA, NMDA, and nicotinic ACh (nACh) receptors on the electrophysiological activity of the primary sensory (AH) and motor (S) neurons of the enteric nervous system are numerically assessed. Results of computer simulations showed that AMPA and L-Asp alone can induce fast action potentials of short duration on AH and S neurons. Costimulation of nACh and AMPA receptors on the soma of the S neuron resulted in periodic spiking activity. A characteristic biphasic response was recorded from the AH neuron after coactivation of AMPA and NMDA receptors. Glutamate alone acting on NMDA receptors caused prolonged depolarization of the AH neuron and failed to depolarize the S neuron. Cojoint stimulation of the AMPA or nACh receptors was required to produce the effect of glutamate. The overall electrical response of neurons to the activation of NMDA receptors was long-term depolarization. Acetylcholine, AMPA, and glutamate acting alone or cojointly enhanced phasic contraction of the longitudinal smooth muscle. Treatment of neurons with AMPA, NMDA, and nACh receptor antagonists revealed intricate properties of the AH and S neurons. Application of MK-801, D-AP5, and CPP reduced the excitability of the AH neuron and totally abolished electrical activity in the S neuron. The information gained into the cotransmission by excitatory amino acids and acetylcholine in the enteric nervous system may be beneficial in the development of novel effective therapeutics to treat diseases associated with altered visceral nociception, i.e. irritable bowel syndrome.

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