scholarly journals An Antagonist of GABA-B Receptors Potentiates Activity of Cortical Epileptic Foci

2012 ◽  
pp. 325-329 ◽  
Author(s):  
P. MAREŠ ◽  
K. BERNÁŠKOVÁ ◽  
H. KUBOVÁ
Keyword(s):  
Receptor Antagonist ◽  
Epileptic Activity ◽  
Local Application ◽  
Subcortical Structures ◽  
Adult Rats ◽  
Bicuculline Methiodide ◽  
Ictal Activity ◽  
Interictal Discharges

Cortical epileptic foci elicited by local application of bicuculline methiodide represent a model of interictal epileptic activity with a transition into ictal phases. We studied a role of GABA-B receptors in this model using GABA-B receptor antagonist CGP35348 in adult rats with implanted cortical electrodes and cannula. CGP35348 (100 or 200 mg/kg i.p.) did not affect interictal discharges but it augmented ictal activity. Latency to the first ictal episode was decreased by the lower dose of CGP35348, duration of episodes was increased by the higher dose. GABA-B receptor antagonist did not influence purely cortical epileptic phenomenon but it is proconvulsant in ictal activity generated with participation of subcortical structures.

Metabotropic glutamate receptor dependent EPSP and EPSP-spike potentiation in area CA1 of the submerged rat hippocampal slice

1996 ◽  
Vol 76 (5) ◽  
pp. 3126-3135 ◽  
Author(s):  
N. A. Breakwell ◽  
M. J. Rowan ◽  
R. Anwyl
Keyword(s):  
Nmda Receptor ◽  
Receptor Antagonist ◽  
Cell Body ◽  
Metabotropic Glutamate Receptor ◽  
Long Term Potentiation ◽  
High Frequency Stimulation ◽  
Excitatory Postsynaptic Potential ◽  
Area Ca1 ◽  
Gabaa Receptor Antagonist

1. We reexamined the important areas of conflict in (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid [(1S,3R)-ACPD]-induced potentiation of the field excitatory postsynaptic potential (EPSP) and, for the first time, investigated the role of mGluRs in EPSP-spike (E-S) coupling. 2. (1S,3R)-ACPD (10 microM) bath applied for 20 min consistently induced a long-lasting potentiation of the dendritic EPSP in area CA1 of submerged rat hippocampal slices, which was considerably faster in onset than described previously. 3. This effect was not associated with any change in presynaptic fiber volley but was dependent on both an intact CA3 connection, because removal of area CA3 blocked (1S,3R)-ACPD-induced potentiation, and also on functional N-methyl-D-aspartate (NMDA) receptors, because (1S,3R)-ACPD-induced potentiation was blocked by inclusion of the NMDA receptor antagonist D(-)-2-amino-5-phosphonopentanoic acid (AP5; 50 microM). 4. (1S,3R)-ACPD induced a long-lasting potentiation of the population spike (PS) amplitude that was consistently larger than that of the EPSP measured in the cell body area. This EPSP-PS (E-S) potentiation was blocked by inclusion of the gamma-aminobuturic acid-A (GABAA) receptor antagonist, picrotoxin (50 microM). 5. E-S potentiation induced by high-frequency stimulation (HFS), which was of the same magnitude as that induced by (1S,3R)-ACPD, was blocked by the mGluR-selective antagonist (+)-alpha-methyl-4-carboxyphenylglycine (+MCPG; 250 microM). +MCPG also blocked HFS-induced long-term potentiation (LTP) of the EPSP measured in the cell body. 6. These results suggest that (1S,3R)-ACPD-induced potentiation is NMDA receptor dependent, contrary to some previous findings, and provide further evidence that both synaptic and E-S potentiation induced by (1S,3R)-ACPD share common mechanisms of expression with HFS-induced LTP. The data emphasize the important role of mGluRs in induction of EPSP LTP and E-S potentiation.

scholarly journals Detection of epileptic activity in presumably normal EEG

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Sara Baldini ◽  
Francesca Pittau ◽  
Gwenael Birot ◽  
Vincent Rochas ◽  
Miralena I Tomescu ◽  
...  
Keyword(s):  
Focal Epilepsy ◽  
Epileptic Activity ◽  
Scalp Eeg ◽  
Vigilance State ◽  
Explained Variance ◽  
Long Term Monitoring ◽  
Interictal Discharges ◽  
The Individual ◽  
Term Monitoring

Abstract Monitoring epileptic activity in the absence of interictal discharges is a major need given the well-established lack of reliability of patients’ reports of their seizures. Up to now, there are no other tools than reviewing the seizure diary; however, seizures may not be remembered or dismissed voluntarily. In the present study, we set out to determine if EEG voltage maps of epileptogenic activity in individual patients can help to identify disease activity, even if their scalp EEG appears normal. Twenty-five patients with pharmacoresistant focal epilepsy were included. For each patient, 6 min of EEG with spikes (yes-spike) and without visually detectable epileptogenic discharges (no-spike) were selected from long-term monitoring recordings (EEG 31–37 channels). For each patient, we identified typical discharges, calculated their average and the corresponding scalp voltage map (‘spike-map’). We then fitted the spike-map for each patient on their (i) EEG epochs with visible spikes, (ii) epochs without any visible spike and (iii) EEGs of 48 controls. The global explained variance was used to estimate the presence of the spike-maps. The individual spike-map occurred more often in the spike-free EEGs of patients compared to EEGs of healthy controls (P = 0.001). Not surprisingly, this difference was higher if the EEGs contained spikes (P < 0.001). In patients, spike-maps were more frequent per second (P < 0.001) but with a shorter mean duration (P < 0.001) than in controls, for both no-spike and yes-spike EEGs. The amount of spike-maps was unrelated to clinical variables, like epilepsy severity, drug load or vigilance state. Voltage maps of spike activity are present very frequently in the scalp EEG of patients, even in presumably normal EEG. We conclude that spike-maps are a robust and potentially powerful marker to monitor subtle epileptogenic activity.

Development of sensitivity to cAMP-inducing hormones in the rat stomach

1984 ◽  
Vol 247 (3) ◽  
pp. G231-G239
Author(s):  
C. Gespach ◽  
Y. Cherel ◽  
G. Rosselin
Keyword(s):  
Biological Activities ◽  
Physiological Role ◽  
H2 Receptor Antagonist ◽  
Adult Rats ◽  
Gastric Glands ◽  
Camp Generation ◽  
Final Maturation ◽  
Noncompetitive Inhibitor ◽  
Regulatory Properties

Development of cAMP responses to secretin, pancreatic glucagon, and histamine was measured in gastric glands of fetal (day 20), postnatal (days 1-30), and adult rats (day 65). cAMP stimulation by these hormones was already detected on day 20 of gestation. cAMP generation showed biphasic variations during the 1st days of life and at the onset of weaning (day 20). Anticipated weaning at day 14 triggered precocious maturation (efficacies) of the cAMP-generating systems sensitive to secretin, glucagon, and histamine without changing the potencies of the hormones. During development, the general characteristics (potency and pharmacological or regulatory properties) of the receptor-cAMP systems studied were comparable with those evidenced in adult rats. At days 5, 20, and 65, vasoactive intestinal peptide and the peptide having N-terminal histidine and C-terminal isoleucine amide (PHI) were about 100 times less potent than secretin (EC50 = 1.5 X 10(-9) M secretin). The histamine action could be blocked by the competitive H2-receptor antagonist cimetidine (70-100% inhibition) as well as by the noncompetitive inhibitor somatostatin (37-62% inhibition). The data indicate that these regulatory hormones (secretin, glucagon(s), histamine, and somatostatin) might have a direct effect on gastric glands and may modulate their biological activities (metabolism, differentiation, proliferation, and exocrine and endocrine secretions) from the neonatal period in rats. The important physiological role of weaning on the final maturation of the cAMP-generating systems in rat gastric glands is underlined.

scholarly journals Sex- and age-based differences in the effect of central serotonin on arterial blood pressure regulation

2020 ◽  
Vol 129 (6) ◽  
pp. 1310-1323
Author(s):  
Jennifer L. Magnusson ◽  
Craig A. Emter ◽  
Kevin J. Cummings
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Nrem Sleep ◽  
Blood Pressure Regulation ◽  
Pressure Regulation ◽  
Adult Rats ◽  
Arterial Blood ◽  
Serotonin Neurons ◽  
Older Males

The role of serotonin in arterial blood pressure (ABP) regulation across states of vigilance is unknown. We hypothesized that adult rats devoid of CNS serotonin (TPH2−/−) have low ABP in wakefulness and NREM sleep, when serotonin neurons are active. However, TPH2−/− rats experience higher ABP than TPH2+/+ rats in wakefulness and REM only, a phenotype present only in older males and not females. CNS serotonin may be critical for preventing high ABP in males with aging.

Human recombinant interleukin-1 receptor antagonist local application for the therapy of inflammatory and allergic airway pathology

Cytokine ◽  
2009 ◽  
Vol 48 (1-2) ◽  
pp. 93
Author(s):  
Andrey Simbirtsev ◽  
Alexander Petrov ◽  
Natalia Pigareva ◽  
Ludmila Solovieva ◽  
Alexander Ischenko ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Interleukin 1 ◽  
Local Application ◽  
Interleukin 1 Receptor Antagonist ◽  
Airway Pathology

scholarly journals Role of interleukin-25 in development of spontaneous arthritis in interleukin-1 receptor antagonist-deficient mice

2017 ◽  
Vol 12 ◽  
pp. 62-65
Author(s):  
Yasuharu Abe ◽  
Aya Nambu ◽  
Sachiko Yamaguchi ◽  
Ayako Takamori ◽  
Hajime Suto ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Interleukin 1 ◽  
Interleukin 1 Receptor Antagonist ◽  
Interleukin 25 ◽  
Deficient Mice

Anticonvulsant and procognitive properties of the non-imidazole histamine H3 receptor antagonist DL77 in male adult rats

2016 ◽  
Vol 106 ◽  
pp. 46-55 ◽  
Author(s):  
Bassem Sadek ◽  
Ali Saad ◽  
Dhanasekaran Subramanian ◽  
Mohamed Shafiullah ◽  
Dorota Łażewska ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Adult Rats ◽  
Male Adult ◽  
Histamine H3 Receptor ◽  
H3 Receptor ◽  
Histamine H3

Role of vasopressin on cardiovascular changes during hemorrhage in conscious rats

1994 ◽  
Vol 267 (5) ◽  
pp. H1713-H1718 ◽  
Author(s):  
Y. Fujisawa ◽  
A. Miyatake ◽  
Y. Hayashida ◽  
Y. Aki ◽  
S. Kimura ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Inhibitory Action ◽  
Sympathetic Nerve Activity ◽  
Stimulatory Action ◽  
Renal Sympathetic Nerve Activity ◽  
Conscious Rats ◽  
V2 Receptor ◽  
Regulation Of Blood Pressure ◽  
Renal Sympathetic

Hypotensive hemorrhage decreases heart rate (HR) and renal sympathetic nerve activity (RSNA). Hemorrhage is a potent stimulus for arginine vasopressin (AVP) release; therefore, AVP may contribute to such inhibitory action of HR and RSNA during hemorrhage. We evaluated the roles of vasopressin on the regulation of blood pressure (BP), HR, and RSNA during hemorrhage using nonpeptide and selective V1- and V2-receptor antagonists (OPC-21268 and OPC-31260) in conscious rats. After hemorrhage (20 ml/kg body wt) BP decreased by 62 +/- 10 mmHg along with bradycardia (-110 +/- 15 beats/min) and renal sympathoinhibition (-50 +/- 8). Pretreatment of V1-receptor antagonist (5 mg/kg iv) did not affect the initial fall of BP but attenuated subsequent BP recovery. Bradycardic and renal sympathoinhibitory responses following hemorrhage were abolished (-14 +/- 24 beats/min and -7 +/- 9) by V1-receptor antagonist. Pretreatment of V2-receptor antagonist (1 mg/kg iv) did not affect the response of BP; however, it did slightly strengthen bradycardia and prolong renal sympathoinhibition. Hemorrhage increased the plasma AVP concentration more than 50-fold. These results indicate that when the plasma concentration of AVP is extremely high during hemorrhage, vasopressin via V1 receptor contributes to BP recovery by the peripheral vasoconstriction and exerts an inhibitory action on RSNA, and vasopressin via V2 receptor exerts opposite stimulatory action on RSNA.

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