The present study investigated the physiological function of presynaptic N-methyl-d aspartate (NMDA) mechanisms in glutamatergic transmission in the rat nucleus tractus solitarius (NTS). Membrane currents were recorded from the NTS second-order neurons by using whole-cell patch pipettes including MK-801 to block postsynaptic NMDA receptors. All experiments were performed under blockade of inhibitory synaptic transmission. Co-application of NMDA and d-serine decreased the tractus solitarius (TS)-evoked excitatory postsynaptic currents (eEPSCs) in 7/12 (58%) of neurons, and increased the paired pulse ratio. The remaining neurons were insensitive to NMDA and d-serine. Application of an NMDA antagonist D-AP5 had no effect on eEPSCs in all 8 neurons tested. Action potential-independent EPSCs (miniature EPSCs; mEPSCs) were recorded in the presence of tetrodotoxin. Co-application of NMDA and d-serine increased the mEPSC frequency but had no significant effect on the amplitude in 5/28 (18%) of neurons. D-AP5 decreased the mEPSC frequency without effect on the amplitude in 6/18 (33%) of neurons. This study demonstrated that (1) NMDA receptors were presynaptically distributed in a subset of NTS second-order neurons and that (2) the presynaptic NMDA receptors played an inhibitory role in TS-mediated release of glutamate and a facilitatory role in spontaneous release of glutamate. The present results suggest that the activation of presynaptic NMDA receptors modulates glutamatergic transmissions in the rat NTS second-order neurons.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.neulet.2014.12.031 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Involvement of the Ipsilateral Tongue, an Intraoral Structure of Referred Pain due to Entrapment of the Greater Occipital Nerve.
Case Rep Neurol Med
December 2024
Department of Neurosurgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
This study reports a rare case of referred pain in the trigeminal nerve distribution caused by entrapment of the greater occipital nerve (GON). Notably, the pain extended to the ipsilateral tongue, an unusual intraoral involvement. GON entrapment can lead to sensitization in secondary nociceptive neurons within the trigeminocervical complex (TCC), which receives signals from both trigeminal and occipital nerves, causing referred facial pain.
View Article and Find Full Text PDFIK Channel Confers Fine-tuning of Rod Bipolar Cell Excitation and Synaptic Transmission in the Retina.
Function (Oxf)
December 2024
Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul, Korea.
During retinal visual processing, rod bipolar cells (RBC) transfer scotopic signals from rods to AII amacrine cells as second-order neurons. Elucidation of the RBC's excitation/inhibition is essential for understanding the visual signal transmission. Excitation mechanisms via mGluR6 and voltage-gated Ca2+ channels in the RBCs and GABAergic inhibitory synaptic inputs have been studied in previous studies.
View Article and Find Full Text PDFFast-slow dynamics in a memristive ion channel-based bionic circuit.
Cogn Neurodyn
December 2024
School of Microelectronics and Control Engineering, Changzhou University, Changzhou, 213159 China.
Electrophysiological properties of ion channels can influence the transport process of ions and the generation of firing patterns in an excitable biological neuron when applying an external stimulus and exceeding the excitable threshold. In this paper, a current stimulus is employed to emulate the external stimulus, and a second-order locally active memristor (LAM) is deployed to characterize the properties of ion channels. Then, a simple bionic circuit possessing the LAM, a capacitor, a DC voltage, and the current stimulus is constructed.
View Article and Find Full Text PDFStability of synchronization manifolds and its nonlinear behaviour in memristive coupled discrete neuron model.
Cogn Neurodyn
December 2024
Center for Research, SRM Institute of Science and Technology-Ramapuram, Chennai, India.
In this study, we investigate the impact of first and second-order coupling strengths on the stability of a synchronization manifold in a Discrete FitzHugh-Nagumo (DFHN) neuron model with memristor coupling. Master Stability Function (MSF) is used to estimate the stability of the synchronized manifold. The MSF of the DFHN model exhibits two zero crossings as we vary the coupling strengths, which is categorized as class .
View Article and Find Full Text PDFEffects of high-order interactions on synchronization of a fractional-order neural system.
Cogn Neurodyn
August 2024
Clinical Engineering Research and Implementation Center (ERKAM), Erciyes University, 38030 Kayseri, Turkey.
Unlabelled: In this study, effects of high-order interactions on synchronization of the fractional-order Hindmarsh-Rose neuron models have been examined deeply. Three different network situations in which first-order coupling, high-order couplings and first-plus second-order couplings included in the neuron models, have been considered, respectively. In order to find the optimal values of the first- and high-order coupling parameters by minimizing the cost function resulted from pairwise and triple interactions, the particle swarm optimization algorithm is employed.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!