A Shout Out to Immature Synapses. Focus on “Different Roles for AMPA and NMDA Receptors in Transmission at the Immature Retinogeniculate Synapse”

2008 ◽  
Vol 99 (2) ◽  
pp. 411-412
Author(s):  
William Guido
Keyword(s):  
Nmda Receptors ◽  
Ampa And Nmda Receptors ◽  
Retinogeniculate Synapse

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.

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.

Chronic intermittent hypoxia alters NMDA and AMPA-evoked currents in NTS neurons receiving carotid body chemoreceptor inputs

2007 ◽  
Vol 292 (6) ◽  
pp. R2259-R2265 ◽  
Author(s):  
Patricia M. de Paula ◽  
Gleb Tolstykh ◽  
Steve Mifflin
Keyword(s):  
Sleep Apnea ◽  
Nmda Receptors ◽  
Dose Response ◽  
Carotid Body ◽  
Intermittent Hypoxia ◽  
Receptor Activation ◽  
Response Curves ◽  
Ampa And Nmda Receptors ◽  
Afferent Inputs ◽  
Dose Response Curves

Chronic exposure to intermittent hypoxia (CIH) has been used in animals to mimic the arterial hypoxemia that accompanies sleep apnea. Humans with sleep apnea and animals exposed to CIH have elevated blood pressures and augmented sympathetic nervous system responses to acute exposures to hypoxia. To test the hypothesis that exposure to CIH alters neurons within the nucleus of the solitary tract (NTS) that integrate arterial chemoreceptor afferent inputs, we measured whole cell currents induced by activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and N-methyl-d-aspartate (NMDA) receptors in enzymatically dispersed NTS neurons from normoxic (NORM) and CIH-exposed rats (alternating cycles of 3 min at 10% O2 followed by 3 min at 21% O2 between 8 AM and 4 PM for 7 days). To identify NTS neurons receiving carotid body afferent inputs the anterograde tracer 4- (4-(dihexadecylamino)styryl- N-methylpyridinum iodide (DiA) was placed onto the carotid body 1 wk before exposure to CIH. AMPA dose-response curves had similar EC50 but maximal responses increased in neurons isolated from DiA-labeled CIH (20.1 ± 0.8 μM, n = 9) compared with NORM (6.0 ± 0.3 μM, n = 8) rats. NMDA dose-response curves also had similar EC50 but maximal responses decreased in CIH (8.4 ± 0.4 μM, n = 8) compared with NORM (19.4 ± 0.6 μM, n = 9) rats. These results suggest reciprocal changes in the number and/or conductance characteristics of AMPA and NMDA receptors. Enhanced responses to AMPA receptor activation could contribute to enhanced chemoreflex responses observed in animals exposed to CIH and humans with sleep apnea.

Postnatal developmental changes in AMPA and NMDA receptors in the rat vestibular nuclei

2000 ◽  
Vol 123 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Nathalie A Sans ◽  
Mireille E Montcouquiol ◽  
Jacqueline Raymond
Keyword(s):  
Nmda Receptors ◽  
Vestibular Nuclei ◽  
Developmental Changes ◽  
Ampa And Nmda Receptors

scholarly journals Electrophysiological Characterization of AMPA and NMDA Receptors in Rat Dorsal Striatum

2009 ◽  
Vol 13 (3) ◽  
pp. 209 ◽  
Author(s):  
Seung Hyun Jeun ◽  
Hyeong Seok Cho ◽  
Ki Jung Kim ◽  
Qing Zhong Li ◽  
Ki-Wug Sung
Keyword(s):  
Nmda Receptors ◽  
Dorsal Striatum ◽  
Ampa And Nmda Receptors ◽  
Electrophysiological Characterization

Silent glutamatergic synapses in the mammalian brain

1999 ◽  
Vol 77 (9) ◽  
pp. 735-737 ◽  
Author(s):  
John TR Isaac ◽  
Roger A Nicoll ◽  
Robert C Malenka
Keyword(s):  
Synaptic Plasticity ◽  
Nmda Receptors ◽  
Neural Activity ◽  
Long Term Potentiation ◽  
Mammalian Brain ◽  
Glutamatergic Synapses ◽  
Synaptic Localization ◽  
Term Potentiation ◽  
Ampa And Nmda Receptors

Excitatory synaptic transmission in the mammalian brain is mediated primarily by α-amino-3-hydroxy-5-methylisoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors that are thought to be co-localized at individual synapses. However, recent electrophysiological and anatomical data suggest that the synaptic localization of AMPA and NMDA receptors may be independently regulated by neural activity. These data are reviewed here and the implications of these findings for the mechanisms underlying synaptic plasticity are discussed.Key words: glutamate receptor, long-term potentiation (LTP), synaptic plasticity, hippocampus, cortex.

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