Role of morphine maintenance dose in the development of tolerance and its attenuation by an NMDA receptor antagonist

2000 ◽  
Vol 148 (1) ◽  
pp. 59-65 ◽  
Author(s):  
R. M. Allen ◽  
L. A. Dykstra
Keyword(s):  
Nmda Receptor ◽  
Receptor Antagonist ◽  
Maintenance Dose ◽  
Nmda Receptor Antagonist ◽  
Development Of Tolerance

Role of AMPA/kainate receptors in transmission of the sympathetic baroreflex in rat CVLM

1997 ◽  
Vol 272 (3) ◽  
pp. R800-R812 ◽  
Author(s):  
T. Miyawaki ◽  
S. Suzuki ◽  
J. Minson ◽  
L. Arnolda ◽  
J. Chalmers ◽  
...  
Keyword(s):  
Nmda Receptor ◽  
Receptor Antagonist ◽  
Nmda Receptor Antagonist ◽  
Baroreceptor Reflex ◽  
Significant Inhibition ◽  
Kainate Receptors ◽  
Ventrolateral Medulla ◽  
Mk 801 ◽  
Aortic Nerve

We examined the role of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptors within the caudal ventrolateral medulla (CVLM) in mediating the sympathetic baroreceptor reflex in anesthetized and paralyzed rats. Bilateral microinjection into CVLM of either DL-2-amino-5-phosphonovaleric acid [APV; a selective N-methyl-D-aspartic acid (NMDA) receptor antagonist, 20 mM, 100 nl] or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; a selective AMPA/kainate receptor antagonist, 2 mM, 100 nl) alone failed to eliminate the aortic nerve stimulation-evoked hypotension and inhibition of splanchnic sympathetic nerve activity (SNA) or the cardiac-related rhythmicity of SNA. All components of the sympathetic-baroreceptor reflex were abolished when kynurenate (100 mM, 30 nl) or mixtures of APV and CNQX (10 and 1 mM, respectively, 100 or 30 nl) were injected into CVLM. Injection of APV or CNQX into CVLM reduced aortic nerve-evoked inhibitory responses of bulbospinal sympathoexcitatory neurons in rostral ventrolateral medulla (RVLM). The extent of this reduction was variable. Usually, significant inhibition was preserved. In seven RVLM neurons, intravenous injection of MK-801 (NMDA receptor antagonist, 2 mg/kg) failed to eliminate aortic nerve-evoked inhibitory responses. However, inhibitory responses were abolished when CNQX was injected into CVLM after intravenous MK-801. We conclude that both NMDA and AMPA/kainate receptors in CVLM transmit baroreceptor information.

Role of the medullary lateral tegmental field in reflex-mediated sympathoexcitation in cats

2004 ◽  
Vol 286 (3) ◽  
pp. R451-R464 ◽  
Author(s):  
Hakan S. Orer ◽  
Gerard L. Gebber ◽  
Shaun W. Phillips ◽  
Susan M. Barman
Keyword(s):  
Nmda Receptor ◽  
Nmda Receptors ◽  
Receptor Antagonist ◽  
Sympathetic Nerve Activity ◽  
Nmda Receptor Antagonist ◽  
Vagal Afferents ◽  
Reflex Pathways ◽  
Excitatory Responses ◽  
Stimulation Of

We tested the hypothesis that blockade of N-methyl-d-aspartate (NMDA) and non-NMDA receptors on medullary lateral tegmental field (LTF) neurons would reduce the sympathoexcitatory responses elicited by electrical stimulation of vagal, trigeminal, and sciatic afferents, posterior hypothalamus, and midbrain periaqueductal gray as well as by activation of arterial chemoreceptors with intravenous NaCN. Bilateral microinjection of a non-NMDA receptor antagonist into LTF of urethane-anesthetized cats significantly decreased vagal afferent-evoked excitatory responses in inferior cardiac and vertebral nerves to 29 ± 8 and 24 ± 6% of control ( n = 7), respectively. Likewise, blockade of non-NMDA receptors significantly reduced chemoreceptor reflex-induced increases in inferior cardiac (from 210 ± 22 to 129 ± 13% of control; n = 4) and vertebral nerves (from 253 ± 41 to 154 ± 20% of control; n = 7) and mean arterial pressure (from 39 ± 7 to 21 ± 5 mmHg; n = 8). Microinjection of muscimol, but not an NMDA receptor antagonist, caused similar attenuation of these excitatory responses. Sympathoexcitatory responses to the other stimuli were not attenuated by microinjection of a non-NMDA receptor antagonist or muscimol into LTF. In fact, excitatory responses elicited by stimulation of trigeminal, and in some cases sciatic, afferents were enhanced. These data reveal two new roles for the LTF in control of sympathetic nerve activity in cats. One, LTF neurons are involved in mediating sympathoexcitation elicited by activation of vagal afferents and arterial chemoreceptors, primarily via activation of non-NMDA receptors. Two, non-NMDA receptor-mediated activation of other LTF neurons tonically suppresses transmission in trigeminal-sympathetic and sciatic-sympathetic reflex pathways.

scholarly journals Effect of Neonatal Treatment With the NMDA Receptor Antagonist, MK-801, During Different Temporal Windows of Postnatal Period in Adult Prefrontal Cortical and Hippocampal Function

2021 ◽  
Vol 15 ◽  
Author(s):  
Maria E. Plataki ◽  
Konstantinos Diskos ◽  
Christos Sougklakos ◽  
Marouso Velissariou ◽  
Alexandros Georgilis ◽  
...  
Keyword(s):  
Nmda Receptor ◽  
Receptor Antagonist ◽  
Nmda Receptor Antagonist ◽  
Fear Extinction ◽  
Gamma Activity ◽  
Postnatal Life ◽  
Contextual Fear ◽  
Mk 801 ◽  
Temporal Windows

The neonatal MK-801 model of schizophrenia has been developed based on the neurodevelopmental and NMDA receptor hypofunction hypotheses of schizophrenia. This animal model is generated with the use of the NMDA receptor antagonist, MK-801, during different temporal windows of postnatal life of rodents leading to behavioral defects in adulthood. However, no studies have examined the role of specific postnatal time periods in the neonatal MK-801 (nMK-801) rodent model and the resulting behavioral and neurobiological effects. Thus, the goal of this study is to systematically investigate the role of NMDA hypofunction, during specific temporal windows in postnatal life on different cognitive and social behavioral paradigms, as well as various neurobiological effects during adulthood. Both female and male mice were injected intraperitoneally (i.p.) with MK-801 during postnatal days 7–14 (p7–14) or 11–15 (p11–15). Control mice were injected with saline during the respective time period. In adulthood, mice were tested in various cognitive and social behavioral tasks. Mice nMK-801-treated on p7–14 show impaired performance in the novel object, object-to-place, and temporal order object recognition (TOR) tasks, the sociability test, and contextual fear extinction. Mice nMK-801-treated on p11–15 only affects performance in the TOR task, the social memory test, and contextual fear extinction. No differences were identified in the expression of NMDA receptor subunits, the synapsin or PSD-95 proteins, either in the prefrontal cortex (PFC) or the hippocampus (HPC), brain regions significantly affected in schizophrenia. The number of parvalbumin (PV)-expressing cells is significantly reduced in the PFC, but not in the HPC, of nMK-801-treated mice on p7–14 compared to their controls. No differences in PV-expressing cells (PFC or HPC) were identified in nMK-801-treated mice on p11–15. We further examined PFC function by recording spontaneous activity in a solution that allows up state generation. We find that the frequency of up states is significantly reduced in both nMK-801-treated mice on p7–14 and p11–15 compared to saline-treated mice. Furthermore, we find adaptations in the gamma and high gamma activity in nMK-801-treated mice. In conclusion, our results show that MK-801 treatment during specific postnatal temporal windows has differential effects on cognitive and social behaviors, as well as on underlying neurobiological substrates.

The role of serotonin in the NMDA receptor antagonist models of psychosis and cognitive impairment

2011 ◽  
Vol 213 (2-3) ◽  
pp. 289-305 ◽  
Author(s):  
Herbert Y. Meltzer ◽  
Masakuni Horiguchi ◽  
Bill W. Massey
Keyword(s):  
Cognitive Impairment ◽  
Nmda Receptor ◽  
Receptor Antagonist ◽  
Nmda Receptor Antagonist

The Role of Ketamine, an NMDA Receptor Antagonist, in the Management of Pain

1995 ◽  
Vol 3 (4) ◽  
pp. 127-134 ◽  
Author(s):  
Jacek Luczak ◽  
Anthony H. Dickenson ◽  
Aleksandra Kotlinska-Lemieszek
Keyword(s):  
Nmda Receptor ◽  
Receptor Antagonist ◽  
Nmda Receptor Antagonist

Glutamatergic projection to RVLM mediates suppression of reflex bradycardia by parabrachial nucleus

1999 ◽  
Vol 276 (5) ◽  
pp. H1482-H1492 ◽  
Author(s):  
Wen-Bin Len ◽  
Julie Y. H. Chan
Keyword(s):  
Nmda Receptor ◽  
Receptor Antagonist ◽  
Nmda Receptor Antagonist ◽  
Systemic Arterial Pressure ◽  
Parabrachial Nucleus ◽  
Ventrolateral Medulla ◽  
Sprague Dawley ◽  
Reflex Bradycardia ◽  
Sprague Dawley Rats

We investigated the role of glutamatergic projection from the parabrachial nucleus (PBN) complex to the rostral ventrolateral medulla (RVLM) in the PBN-induced suppression of reflex bradycardia in adult Sprague-Dawley rats that were maintained under pentobarbital anesthesia. Under stimulus conditions that did not appreciably alter the baseline systemic arterial pressure and heart rate, electrical (10-s train of 0.5-ms pulses, at 10–20 μA and 10–20 Hz) or chemical (l-glutamate, 1 nmol) stimulation of the ventrolateral regions and Köelliker-Fuse (KF) subnucleus of the PBN complex significantly suppressed the reflex bradycardia in response to transient hypertension evoked by phenylephrine (5 μg/kg iv). The PBN-induced suppression of reflex bradycardia was appreciably reversed by bilateral microinjection into the RVLM of the N-methyl-d-aspartate (NMDA)-receptor antagonist MK-801 (500 pmol) or the non-NMDA-receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (50 pmol). Anatomically, most of the retrogradely labeled neurons in the ventrolateral regions and KF subnucleus of the ipsilateral PBN complex after microinjection of fast blue into the RVLM were also immunoreactive to anti-glutamate antiserum. These results suggest that a direct glutamatergic projection to the RVLM from topographically distinct regions of the PBN complex may participate in the suppression of reflex bradycardia via activation of both NMDA and non-NMDA receptors at the RVLM.

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