Decreased N-methyl-d-aspartic acid (NMDA) receptor levels are associated with mercury exposure in wild and captive mink

1. The present study investigated opioid-mediated modulation of N-methyl-D-aspartic acid (NMDA)-evoked responses of trigeminothalamic neurons in the superficial and deeper dorsal horn of the medulla (trigeminal nucleus caudalis) in rats anesthetized with urethane. 2. Microiontophoretic application of NMDA activated 18/19 trigeminothalamic neurons. Administration of [D-Ala2, N-Me-Phe4,Gly5-ol]-Enkephalin, a selective mu-opioid receptor agonist, reduced the NMDA-evoked responses in 77% of trigeminothalamic neurons. [D-Pen2,5]-Enkephalin, a selective delta-opioid receptor agonist, produced inhibition of NMDA-evoked responses in 36% of neurons. 3. We suggest that 1) NMDA-receptor activation excites trigeminothalamic nociceptive neurons and may, therefore, mediate nociceptive transmission in the medullary dorsal horn; and 2) the predominantly inhibitory modulation of NMDA-receptor-mediated responses of nociceptive trigeminothalamic neurons by activation of mu- and delta-opioid receptors may provide a neural mechanism for the antinociceptive actions of opioids.

Download Full-text

Searsia species with affinity to the N-methyl-d-aspartic acid (NMDA) receptor

South African Journal of Botany ◽

10.1016/j.sajb.2011.10.002 ◽

2012 ◽

Vol 78 ◽

pp. 312-314

Author(s):

A.K. Jäger ◽

D.M. Knap ◽

B. Nielsen ◽

G.I. Stafford ◽

J. Van Staden

Keyword(s):

Nmda Receptor ◽

Aspartic Acid

Download Full-text

Involvement of N-Methyl-D-Aspartic Acid Receptor and DL-α-Amino-3-Hydroxy-5- Methyl-4-Isoxazole Propionic Acid Receptor in Ginsenosides Rb1 and Rb3 against Oxygen-Glucose Deprivation-Induced Injury in Hippocampal Slices from Rat

Pharmacology ◽

10.1159/000481710 ◽

2017 ◽

Vol 101 (3-4) ◽

pp. 133-139 ◽

Cited By ~ 1

Author(s):

Shan Jiang ◽

De-Fang Fang ◽

Ying Chen

Keyword(s):

Nmda Receptor ◽

Synaptic Transmission ◽

Aspartic Acid ◽

Propionic Acid ◽

Ampa Receptor ◽

Hippocampal Slices ◽

Glucose Deprivation ◽

Oxygen Glucose Deprivation ◽

Protective Effects ◽

Acid Receptor

Objective: Ginsenosides, Rb1 and Rb3, are the major protopanaxadiol components of ginseng saponin. In the present study, the influences of ginsenosides Rb1 and Rb3 on N-methyl-D-aspartic acid (NMDA) receptor or DL-α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor-mediated synaptic transmission after oxygen-glucose deprivation (OGD) were investigated. Methods: NMDA receptor population spike (NMDA-PS) or AMPA receptor-mediated population spike (AMPA-PS) was recorded in the CA1 pyramidal cell layer of rat hippocampal slices by electrophysiological techniques. Results: Under normal conditions, ginsenosides Rb3 and Rb1 depressed glutamate receptors-mediated synaptic transmission. Fourteen min of OGD resulted in a poor recovery amplitude of NMDA-PS or AMPA-PS after reoxygenation. Ginsenoside Rb3 significantly delayed the appearance of transient recovery of PS during OGD, and improved the recovery amplitudes of NMDA-PS and AMPA-PS after reoxygenation. However, the similar protective effects of ginsenoside Rb1 were observed only on NMDA-PS but not AMPA-PS. Conclusion: These results suggest that ginsenosides Rb1 and Rb3 have the different inhibitions on NMDA and AMPA receptors-mediated response, which may partially explain the different protective effects of these agents on ischemic neuronal death.

Download Full-text

N-Methyl-d-aspartic Acid (NMDA) Receptor Is Involved in the Inhibitory Effect of Ketamine on Human Sperm Functions

International Journal of Molecular Sciences ◽

10.3390/ijms222212370 ◽

2021 ◽

Vol 22 (22) ◽

pp. 12370

Author(s):

Ying Chen ◽

Wenqing Xu ◽

Yuan Yuan ◽

Houyang Chen ◽

Shuangyan Zheng ◽

...

Keyword(s):

Nmda Receptor ◽

Aspartic Acid ◽

Calcium Concentration ◽

Human Sperm ◽

Inhibitory Effect ◽

Sperm Function ◽

Tail Region ◽

Animal Medicine ◽

Specific Signaling Pathway ◽

Sperm Functions

Ketamine, which used to be widely applied in human and animal medicine as a dissociative anesthetic, has become a popular recreational drug because of its hallucinogenic effect. Our previous study preliminarily proved that ketamine could inhibit human sperm function by affecting intracellular calcium concentration ([Ca2+]i). However, the specific signaling pathway of [Ca2+]i induced by ketamine in human sperm is still not clear yet. Here, the N-methyl-d-aspartic acid (NMDA) receptor was detected in the tail region of human sperm. Its physiological ligand, NMDA (50 μM), could reverse ketamine’s inhibitory effect on human sperm function, and its antagonist, MK801 (100 μM), could restrain the effect of NMDA. The inhibitory effect caused by 4 mM ketamine or 100 μM MK801 on [Ca2+]i, which is a central factor in the regulation of human sperm function, could also be recovered by 50 μM NMDA. The results suggest that the NMDA receptor is probably involved in the inhibitory effect of ketamine on human sperm functions.

Download Full-text

Blocking N-Methyl-D-aspartic Acid (NMDA) Receptor Inhibits Heat-Sensitization Response of Moxibustion in Stroke Rats

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2021/6463688 ◽

2021 ◽

Vol 2021 ◽

pp. 1-6

Author(s):

Zhimai Lyu ◽

Dandan Huang ◽

Dingyi Xie ◽

Yanjun Chen ◽

Chunmei Wu ◽

...

Keyword(s):

Nmda Receptor ◽

Aspartic Acid ◽

Negative Impact ◽

Long Term Potentiation ◽

Nmda Receptor Antagonist ◽

Cerebral Infarct ◽

Significant Drop ◽

Vehicle Injection ◽

Heat Sensitization

Our previous studies demonstrated that effects of moxibustion heavily relied on heat-sensitization response, a specific sensation induced by moxibustion in the ill body. On the sensation, long-term potentiation (LTP) of prelimbic cortex was attributed to heat-sensitization responses. The N-methyl-D-aspartic acid (NMDA) receptor plays a key role in LTP induction; however, little is known about the role of NMDA receptor in heat-sensitization response. The present study investigated the role of NMDA receptor in heat-sensitization response, specifically, NMDA receptor was inhibited by competitive glutamatergic antagonist, (±)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP), observing the frequency of heat-sensitization response in moxibustion treatment and evaluating the conducive outcomes to cerebral infarct rats for rehabilitation. Heat-sensitization response in cerebral infarct rats was regularly measured for all the samples when exposed to moxibustion. Intraperitoneal injection of CPP was conducted, and soon afterwards, a significant drop of heat-sensitization response in all the samples was measured. Moreover, moxibustion efficiency on rehabilitation was unfavourably affected in cerebral infarct rats when compared to vehicle injection control. This indicated that NMDA receptor antagonist made a negative impact on induction of heat-sensitization response and consequently affected cerebral infarct rats to rehabilitate under moxibustion treatment. It also suggested that activating NMDA receptor played a positive part in ischemic stroke rehabilitation, and regulating its activity could be a feasible way to increase heat-sensitization response, improving the effect of moxibustion.

Download Full-text