scholarly journals Positive Allosteric Modulator of mGluR4 PHCCC Exhibits Proconvulsant Action in Three Models of Epileptic Seizures in Immature Rats

2012 ◽  
pp. 619-628 ◽  
Author(s):  
E. SZCZUROWSKA ◽  
P. MAREŠ
Keyword(s):  
Metabotropic Glutamate Receptors ◽  
Rhythmic Activity ◽  
Epileptic Seizures ◽  
Allosteric Modulator ◽  
Anticonvulsant Effect ◽  
Positive Allosteric Modulator ◽  
Adult Rats ◽  
Absence Seizures ◽  
Implanted Electrodes ◽  
Immature Rats

The activation of metabotropic glutamate receptors subtype 4 (mGluR4) potentiates models of absence seizures in adult rats. These seizures are age-dependent, but data concerning the role of mGluR4 in immature brain is insufficient. N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen-1acarboxamide (PHCCC), which is a positive allosteric modulator of these receptors, was used in three different models of seizures in immature rats: 1) convulsions induced by high doses of pentetrazol (PTZ; a model of generalised tonic-clonic seizures); 2) rhythmic electro-encephalographic (EEG) activity induced by low doses of PTZ (a model of absence seizures); and 3) electrically elicited cortical afterdischarges (ADs, a model of myoclonic seizures). We administered four doses of PHCCC (1, 3, 10 and 20 mg/kg) in PTZ-induced convulsions and two doses (3 and 10 mg/kg) in the two electrophysiological models of freely moving rats with implanted electrodes. Every dose and age group consisted from 8 to 10 rats. PTZ-elicited convulsions were not significantly influenced by PHCCC. In contrast, PHCCC potentiated the effect of a subconvulsant dose (60 mg/kg) of PTZ. The 10-mg/kg dose of PHCCC significantly prolonged the duration of PTZ-induced rhythmic activity episodes and shortened the intervals between individual episodes in 25-day-old rats (P25). In contrast, this potentiation was not seen in P18 rats. Cortical ADs were significantly prolonged with repeated stimulations by both doses of PHCCC in P12 and P18 animals. P25 rats exhibited only slightly longer AD durations. In conclusion, we did not find any anticonvulsant effect of PHCCC. On the contrary, proconvulsant action was demonstrated in all three models in immature rats.

scholarly journals Models of Epileptic Seizures in Immature Rats

2012 ◽  
pp. S103-S108 ◽  
Author(s):  
P. MAREŠ
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Antiepileptic Drugs ◽  
Epileptic Seizures ◽  
Limbic Seizures ◽  
Absence Seizures ◽  
Motor Abilities ◽  
Infancy And Childhood ◽  
Immature Rats ◽  
Age Dependent

Models of basic types of epileptic seizures are elaborated not only in adult but also in immature rodents. It is important because at least half of human epilepsies starts during infancy and childhood. This paper presents a review of chemically and electrically induced models of generalized convulsive and nonconvulsive (absence) seizures as well as models of partial simple (neocortical) and complex (limbic) seizures in immature rats. These models can also serve as a tool for study the development of central nervous system and motor abilities because the level of maturation is reflected in seizure semiology. Age-dependent models of epileptic seizures (absences and flexion seizures) are discussed. Models of seizures in immature animals should be used for testing of potential antiepileptic drugs.

Correction: Structural modeling and role of HAX-1 as a positive allosteric modulator of human serine protease HtrA2

2020 ◽  
Vol 477 (2) ◽  
pp. 459-459
Author(s):  
Lalith K. Chaganti ◽  
Shubhankar Dutta ◽  
Raja Reddy Kuppili ◽  
Mriganka Mandal ◽  
Kakoli Bose
Keyword(s):  
Serine Protease ◽  
Structural Modeling ◽  
Allosteric Modulator ◽  
Positive Allosteric Modulator

scholarly journals Discovery of BNC375, a Potent, Selective, and Orally Available Type I Positive Allosteric Modulator of α7 nAChRs

2019 ◽  
Vol 10 (5) ◽  
pp. 754-760 ◽  
Author(s):  
Andrew J. Harvey ◽  
Thomas D. Avery ◽  
Laurent Schaeffer ◽  
Christophe Joseph ◽  
Belinda C. Huff ◽  
...  
Keyword(s):  
Allosteric Modulator ◽  
Type I ◽  
Positive Allosteric Modulator ◽  
Α7 Nachrs

scholarly journals Comparison of pregnenolone sulfate, pregnanolone and estradiol levels between patients with menstrually-related migraine and controls: an exploratory study

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Cecilia Rustichelli ◽  
Elisa Bellei ◽  
Stefania Bergamini ◽  
Emanuela Monari ◽  
Flavia Lo Castro ◽  
...  
Keyword(s):  
Exploratory Study ◽  
Serum Levels ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Allosteric Modulator ◽  
Positive Allosteric Modulator ◽  
Pregnenolone Sulfate ◽  
Menstrually Related Migraine ◽  
History Of ◽  
Estradiol Levels

Abstract Background Neurosteroids affect the balance between neuroexcitation and neuroinhibition but have been little studied in migraine. We compared the serum levels of pregnenolone sulfate, pregnanolone and estradiol in women with menstrually-related migraine and controls and analysed if a correlation existed between the levels of the three hormones and history of migraine and age. Methods Thirty women (mean age ± SD: 33.5 ± 7.1) with menstrually-related migraine (MM group) and 30 aged- matched controls (mean age ± SD: 30.9 ± 7.9) participated in the exploratory study. Pregnenolone sulfate and pregnanolone serum levels were analysed by liquid chromatography-tandem mass spectrometry, while estradiol levels by enzyme-linked immunosorbent assay. Results Serum levels of pregnenolone sulfate and pregnanolone were significantly lower in the MM group than in controls (pregnenolone sulfate: P = 0.0328; pregnanolone: P = 0.0271, Student’s t-test), while estradiol levels were similar. In MM group, pregnenolone sulfate serum levels were negatively correlated with history of migraine (R2 = 0.1369; P = 0.0482) and age (R2 = 0.2826, P = 0.0025) while pregnenolone sulfate levels were not age-related in the control group (R2 = 0.04436, P = 0.4337, linear regression analysis). Conclusion Low levels of both pregnanolone, a positive allosteric modulator of the GABAA receptor, and pregnenolone sulfate, a positive allosteric modulator of the NMDA receptor, involved in memory and learning, could contribute either to headache pain or the cognitive dysfunctions reported in migraine patients. Overall, our results agree with the hypothesis that migraine is a disorder associated with a loss of neurohormonal integrity, thus supporting the therapeutic potential of restoring low neurosteroid levels in migraine treatment.

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