scholarly journals Studying properties of neurotransmitter receptors by non-stationary noise analysis of spontaneous postsynaptic currents and agonist-evoked responses in outside-out patches

2007 ◽  
Vol 2 (2) ◽  
pp. 434-448 ◽  
Author(s):  
Espen Hartveit ◽  
Margaret Lin Veruki
Keyword(s):  
Noise Analysis ◽  
Neurotransmitter Receptors ◽  
Evoked Responses ◽  
Stationary Noise ◽  
Postsynaptic Currents ◽  
Spontaneous Postsynaptic Currents

scholarly journals Maturation of NMDA receptor-mediated spontaneous postsynaptic currents in the rat locus coeruleus neurons

2020 ◽  
Vol 107 (1) ◽  
pp. 18-29
Author(s):  
M Kourosh-Arami ◽  
S Hajizadeh
Keyword(s):  
Nmda Receptor ◽  
Nmda Receptors ◽  
Locus Coeruleus ◽  
Cell Voltage ◽  
Mammalian Brain ◽  
Glutamatergic Synapses ◽  
Excitatory Postsynaptic Currents ◽  
Postnatal Maturation ◽  
Postsynaptic Currents ◽  
Spontaneous Postsynaptic Currents

AbstractIntroductionDuring mammalian brain development, neural activity leads to maturation of glutamatergic innervations to locus coeruleus. In this study, fast excitatory postsynaptic currents mediated by N-methyl-d-aspartate (NMDA) receptors were evaluated to investigate the maturation of excitatory postsynaptic currents in locus coeruleus (LC) neurons.MethodsNMDA receptor-mediated synaptic currents in LC neurons were evaluated using whole-cell voltage-clamp recording during the primary postnatal weeks. This technique was used to calculate the optimum holding potential for NMDA receptor-mediated currents and the best frequency for detecting spontaneous excitatory postsynaptic currents (sEPSC).ResultsThe optimum holding potential for detecting NMDA receptor-mediated currents was + 40 to + 50 mV in LC neurons. The frequency, amplitude, rise time, and decay time constant of synaptic responses depended on the age of the animal and increased during postnatal maturation.ConclusionThese findings suggest that most nascent glutamatergic synapses express functional NMDA receptors in the postnatal coerulear neurons, and that the activities of the neurons in this region demonstrate an age-dependent variation.

scholarly journals Non-Stationary Noise Analysis of Magnetic Sensors using Allan Variance

2017 ◽  
Vol 131 (4) ◽  
pp. 1126-1128 ◽  
Author(s):  
K. Draganová ◽  
V. Moucha ◽  
T. Volčko ◽  
K. Semrád
Keyword(s):  
Noise Analysis ◽  
Allan Variance ◽  
Magnetic Sensors ◽  
Stationary Noise

Non-genomic action of vitamin D3 on N-methyl-D-aspartate and kainate receptor-mediated actions in juvenile gonadotrophin-releasing hormone neurons

2017 ◽  
Vol 29 (6) ◽  
pp. 1231 ◽  
Author(s):  
Pravin Bhattarai ◽  
Janardhan P. Bhattarai ◽  
Min Sun Kim ◽  
Seong Kyu Han
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Critical Role ◽  
Kainate Receptor ◽  
Inward Current ◽  
Releasing Hormone ◽  
Postsynaptic Currents ◽  
Gnrh Neurons ◽  
Gonadotrophin Releasing Hormone ◽  
Spontaneous Postsynaptic Currents

Vitamin D is a versatile signalling molecule that plays a critical role in calcium homeostasis. There are several studies showing the genomic action of vitamin D in the control of reproduction; however, the quick non-genomic action of vitamin D at the hypothalamic level is not well understood. Therefore, to investigate the effect of vitamin D on juvenile gonadotrophin-releasing hormone (GnRH) neurons, excitatory neurotransmitter receptor agonists N-methyl-D-aspartate (NMDA, 30 μM) and kainate (10 μM) were applied in the absence or in the presence of vitamin D3 (VitaD3, 10 nM). The NMDA-mediated responses were decreased by VitaD3 in the absence and in the presence of tetrodotoxin (TTX), a sodium-channel blocker, with the mean relative inward current being 0.56 ± 0.07 and 0.66 ± 0.07 (P < 0.05), respectively. In addition, VitaD3 induced a decrease in the frequency of gamma-aminobutyric acid mediated (GABAergic) spontaneous postsynaptic currents and spontaneous postsynaptic currents induced by NMDA application with a mean relative frequency of 0.595 ± 0.07 and 0.56 ± 0.09, respectively. Further, VitaD3 decreased the kainate-induced inward currents in the absence and in the presence of TTX with a relative inward current of 0.64 ± 0.06 and 0.68 ± 0.06, respectively (P < 0.05). These results suggest that VitaD3 has a non-genomic action and partially inhibits the NMDA and kainate receptor-mediated actions of GnRH neurons, suggesting that VitaD3 may regulate the hypothalamic–pituitary–gonadal (HPG) axis at the time of pubertal development.

scholarly journals Miniature Inhibitory Postsynaptic Currents in CA1 Pyramidal Neurons After Kindling Epileptogenesis

1999 ◽  
Vol 82 (3) ◽  
pp. 1352-1362 ◽  
Author(s):  
Corette J. Wierenga ◽  
Wytse J. Wadman
Keyword(s):  
Pyramidal Neurons ◽  
Single Channel ◽  
Noise Analysis ◽  
Specific Class ◽  
Inhibitory Postsynaptic Currents ◽  
Ca1 Pyramidal Neurons ◽  
Postsynaptic Currents ◽  
Generalized Seizures ◽  
Significant Difference ◽  
The Difference

Miniature inhibitory postsynaptic currents (mIPSCs) were measured in CA1 pyramidal neurons from long-term kindled rats (>6 weeks after they reached the stage of generalized seizures) and compared with controls. A large reduction in the number of mIPSCs was observed in a special group of large mIPSCs (amplitude >75 pA). The frequency of mIPSCs in this group was reduced from 0.042 Hz in controls to 0.027 Hz in the kindled animals. The reduction in this group resulted in a highly significant difference in the amplitude distributions. A distinction was made between fast mIPSCs (rise time <2.8 ms) and slow mIPSCs. Fast mIPSCs, which could originate from synapses onto the soma and proximal dendrites, had significantly larger amplitudes than slow mIPSCs, which could originate from more distal synapses (35.4 ± 1.1 vs. 26.2 ± 0.4 pA in the kindled group; means ± SE). The difference in the value of the mean of all amplitudes and frequency of fast and slow mIPSCs did not reach significance when the kindled group was compared with controls. The mIPSC kinetics were not different after kindling, from which we conclude that the receptor properties had not changed. Nonstationary noise analysis of the largest mIPSCs suggested that the single-channel conductance and the number of postsynaptic receptors was similar in the kindled and control groups. Our results suggest a 40–50% reduction in a small fraction of (peri-) somatic synapses with large or complex postsynaptic structure after kindling. This functionally relevant reduction may be related to previously observed loss of a specific class of interneurons. Our findings are consistent with a reduction in inhibitory drive in the CA1 area. Such a reduction could underlie the enhanced seizure susceptibility after kindling epileptogenesis.

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