Biomaterial Database

Late low magnesium-induced epileptiform activity in rat entorhinal cortex slices becomes insensitive to the anticonvulsant valproic acid. 1990

J P Dreier, and U Heinemann

Institut für Neurophysiologie, Zentrum für Physiologie und Pathophysiologie, Universität zu Köln, Cologne, F.R.G.

We investigated time-dependent changes in low magnesium-induced epileptiform activity in combined rat entorhinal cortex/hippocampal slices with extracellular recording techniques. While in area CA3 short interictal discharges are generated without any major changes in activity during prolonged recording periods, initial tonic clonic ictaform events in the entorhinal cortex may change with time. We observed often a transition into a state of recurrent tonic activity without any clonic afterdischarges. Alternatively, seizures could stay in the clonic discharge mode for the rest of the experiment. These different seizure states were not equally affected by the anticonvulsant valproic acid. While the early clonic tonic discharges in the entorhinal cortex and the interictal like activity in area CA3 were effectively suppressed by valproic acid (VPA) the late recurrent tonic seizure discharge state was unaffected by the drug. It was, however, still sensitive to the N-methyl-D-aspartate (NMDA) receptor antagonist 2-aminophosphonovalerate. These findings point to seizure-induced changes in neuronal interaction in rat entorhinal cortex.

UI	MeSH Term	Description	Entries
D008032	Limbic System	A set of forebrain structures common to all mammals that is defined functionally and anatomically. It is implicated in the higher integration of visceral, olfactory, and somatic information as well as homeostatic responses including fundamental survival behaviors (feeding, mating, emotion). For most authors, it includes the AMYGDALA; EPITHALAMUS; GYRUS CINGULI; hippocampal formation (see HIPPOCAMPUS); HYPOTHALAMUS; PARAHIPPOCAMPAL GYRUS; SEPTAL NUCLEI; anterior nuclear group of thalamus, and portions of the basal ganglia. (Parent, Carpenter's Human Neuroanatomy, 9th ed, p744; NeuroNames, http://rprcsgi.rprc.washington.edu/neuronames/index.html (September 2, 1998)).	Limbic Systems,System, Limbic,Systems, Limbic
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008275	Magnesium Deficiency	A nutritional condition produced by a deficiency of magnesium in the diet, characterized by anorexia, nausea, vomiting, lethargy, and weakness. Symptoms are paresthesias, muscle cramps, irritability, decreased attention span, and mental confusion, possibly requiring months to appear. Deficiency of body magnesium can exist even when serum values are normal. In addition, magnesium deficiency may be organ-selective, since certain tissues become deficient before others. (Harrison's Principles of Internal Medicine, 12th ed, p1936)	Deficiency, Magnesium,Deficiencies, Magnesium,Magnesium Deficiencies
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D004827	Epilepsy	A disorder characterized by recurrent episodes of paroxysmal brain dysfunction due to a sudden, disorderly, and excessive neuronal discharge. Epilepsy classification systems are generally based upon: (1) clinical features of the seizure episodes (e.g., motor seizure), (2) etiology (e.g., post-traumatic), (3) anatomic site of seizure origin (e.g., frontal lobe seizure), (4) tendency to spread to other structures in the brain, and (5) temporal patterns (e.g., nocturnal epilepsy). (From Adams et al., Principles of Neurology, 6th ed, p313)	Aura,Awakening Epilepsy,Seizure Disorder,Epilepsy, Cryptogenic,Auras,Cryptogenic Epilepsies,Cryptogenic Epilepsy,Epilepsies,Epilepsies, Cryptogenic,Epilepsy, Awakening,Seizure Disorders
D006624	Hippocampus	A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.	Ammon Horn,Cornu Ammonis,Hippocampal Formation,Subiculum,Ammon's Horn,Hippocampus Proper,Ammons Horn,Formation, Hippocampal,Formations, Hippocampal,Hippocampal Formations,Hippocampus Propers,Horn, Ammon,Horn, Ammon's,Proper, Hippocampus,Propers, Hippocampus,Subiculums
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000927	Anticonvulsants	Drugs used to prevent SEIZURES or reduce their severity.	Anticonvulsant,Anticonvulsant Drug,Anticonvulsive Agent,Anticonvulsive Drug,Antiepileptic,Antiepileptic Agent,Antiepileptic Agents,Antiepileptic Drug,Anticonvulsant Drugs,Anticonvulsive Agents,Anticonvulsive Drugs,Antiepileptic Drugs,Antiepileptics,Agent, Anticonvulsive,Agent, Antiepileptic,Agents, Anticonvulsive,Agents, Antiepileptic,Drug, Anticonvulsant,Drug, Anticonvulsive,Drug, Antiepileptic,Drugs, Anticonvulsant,Drugs, Anticonvulsive,Drugs, Antiepileptic
D014635	Valproic Acid	A fatty acid with anticonvulsant and anti-manic properties that is used in the treatment of EPILEPSY and BIPOLAR DISORDER. The mechanisms of its therapeutic actions are not well understood. It may act by increasing GAMMA-AMINOBUTYRIC ACID levels in the brain or by altering the properties of VOLTAGE-GATED SODIUM CHANNELS.	Dipropyl Acetate,Divalproex,Sodium Valproate,2-Propylpentanoic Acid,Calcium Valproate,Convulsofin,Depakene,Depakine,Depakote,Divalproex Sodium,Ergenyl,Magnesium Valproate,Propylisopropylacetic Acid,Semisodium Valproate,Valproate,Valproate Calcium,Valproate Sodium,Valproic Acid, Sodium Salt (2:1),Vupral,2 Propylpentanoic Acid
D015763	2-Amino-5-phosphonovalerate	The D-enantiomer is a potent and specific antagonist of NMDA glutamate receptors (RECEPTORS, N-METHYL-D-ASPARTATE). The L form is inactive at NMDA receptors but may affect the AP4 (2-amino-4-phosphonobutyrate; APB) excitatory amino acid receptors.	2-Amino-5-phosphonopentanoic Acid,2-Amino-5-phosphonovaleric Acid,2-APV,2-Amino-5-phosphonopentanoate,5-Phosphononorvaline,d-APV,dl-APV,2 Amino 5 phosphonopentanoate,2 Amino 5 phosphonopentanoic Acid,2 Amino 5 phosphonovalerate,2 Amino 5 phosphonovaleric Acid,5 Phosphononorvaline