Biomaterial Database

The effects of convulsant doses of penicillin on primary afferents, dorsal root ganglion cells, and on 'presynaptic' inhibition in the spinal cord. 1980

C G Kinnes, and B Connors, and G Somjen

Intracellular recordings were made from neurons in dorsal root ganglia (DRG) of rats, isolated in vitro. The depolarization of DRG cells caused by the application of gamma-aminobutyric acid (GABA) diminished reversibly when penicillin (0.08--2.0 mM) was added to the bathing fluid. The decrease of the input resistance of DRG cells measured during GABA perfusion was also depressed in the presence of penicillin, but no evidence of a shift of the reversal potential of the GABA-induced depolarization was found. Nor did penicillin (up to 10 mM) cause a change in the voltage-current function, in electrical excitability, in the inclination to repetitive firing, bursting discharge, or after discharge. In decapitate cat preparation the amplitude of the negative dorsal root potential (DRP or DR V) diminished by 0--50% after the i.v. administration of 0.5--1.0 X 10(6) I.U./kg (the convulsant dose) of penicillin. Post-tetanic depression of the DRP was aggravated by penicillin. The degree of depression of the DRP bore no relationship to the promptness of the eruption, and to the intensity, of the seizure activity induced by penicillin. The rates of rise and fall of the negative DRP (DR V) were consistently slowed, the positive DRP (DR VI) reduced, and the dorsal root reflex (DRR) blocked by penicillin. Inhibitory reflex effects presumed to be presynaptic were either enhanced or unchanged, never depressed by penicillin. This was seen when inhibitory function was gauged by monosynaptic reflex amplitude, and also from the inhibition of ventral root electrotonic excitatory postsynaptic potentials (VP EPSPs). Possible explanations of these seemingly paradoxical findings are discussed, with arguments in favor and against each.

UI	MeSH Term	Description	Entries
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D010400	Penicillin G	A penicillin derivative commonly used in the form of its sodium or potassium salts in the treatment of a variety of infections. It is effective against most gram-positive bacteria and against gram-negative cocci. It has also been used as an experimental convulsant because of its actions on GAMMA-AMINOBUTYRIC ACID mediated synaptic transmission.	Benzylpenicillin,Benpen,Benzylpenicillin Potassium,Coliriocilina,Crystapen,Or-pen,Parcillin,Pekamin,Pengesod,Penibiot,Penicilina G Llorente,Penicillin G Jenapharm,Penicillin G Potassium,Penicillin G Sodium,Penicillin Grünenthal,Penilevel,Peniroger,Pfizerpen,Sodiopen,Sodipen,Sodium Benzylpenicillin,Sodium Penicillin,Unicilina,Ursopen,Van-Pen-G
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D005071	Evoked Potentials	Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.	Event Related Potential,Event-Related Potentials,Evoked Potential,N100 Evoked Potential,P50 Evoked Potential,N1 Wave,N100 Evoked Potentials,N2 Wave,N200 Evoked Potentials,N3 Wave,N300 Evoked Potentials,N4 Wave,N400 Evoked Potentials,P2 Wave,P200 Evoked Potentials,P50 Evoked Potentials,P50 Wave,P600 Evoked Potentials,Potentials, Event-Related,Event Related Potentials,Event-Related Potential,Evoked Potential, N100,Evoked Potential, N200,Evoked Potential, N300,Evoked Potential, N400,Evoked Potential, P200,Evoked Potential, P50,Evoked Potential, P600,Evoked Potentials, N100,Evoked Potentials, N200,Evoked Potentials, N300,Evoked Potentials, N400,Evoked Potentials, P200,Evoked Potentials, P50,Evoked Potentials, P600,N1 Waves,N2 Waves,N200 Evoked Potential,N3 Waves,N300 Evoked Potential,N4 Waves,N400 Evoked Potential,P2 Waves,P200 Evoked Potential,P50 Waves,P600 Evoked Potential,Potential, Event Related,Potential, Event-Related,Potential, Evoked,Potentials, Event Related,Potentials, Evoked,Potentials, N400 Evoked,Related Potential, Event,Related Potentials, Event,Wave, N1,Wave, N2,Wave, N3,Wave, N4,Wave, P2,Wave, P50,Waves, N1,Waves, N2,Waves, N3,Waves, N4,Waves, P2,Waves, P50
D005680	gamma-Aminobutyric Acid	The most common inhibitory neurotransmitter in the central nervous system.	4-Aminobutyric Acid,GABA,4-Aminobutanoic Acid,Aminalon,Aminalone,Gammalon,Lithium GABA,gamma-Aminobutyric Acid, Calcium Salt (2:1),gamma-Aminobutyric Acid, Hydrochloride,gamma-Aminobutyric Acid, Monolithium Salt,gamma-Aminobutyric Acid, Monosodium Salt,gamma-Aminobutyric Acid, Zinc Salt (2:1),4 Aminobutanoic Acid,4 Aminobutyric Acid,Acid, Hydrochloride gamma-Aminobutyric,GABA, Lithium,Hydrochloride gamma-Aminobutyric Acid,gamma Aminobutyric Acid,gamma Aminobutyric Acid, Hydrochloride,gamma Aminobutyric Acid, Monolithium Salt,gamma Aminobutyric Acid, Monosodium Salt
D005727	Ganglia, Spinal	Sensory ganglia located on the dorsal spinal roots within the vertebral column. The spinal ganglion cells are pseudounipolar. The single primary branch bifurcates sending a peripheral process to carry sensory information from the periphery and a central branch which relays that information to the spinal cord or brain.	Dorsal Root Ganglia,Spinal Ganglia,Dorsal Root Ganglion,Ganglion, Spinal,Ganglia, Dorsal Root,Ganglion, Dorsal Root,Spinal Ganglion
D000344	Afferent Pathways	Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.	Afferent Pathway,Pathway, Afferent,Pathways, Afferent
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
D012640	Seizures	Clinical or subclinical disturbances of cortical function due to a sudden, abnormal, excessive, and disorganized discharge of brain cells. Clinical manifestations include abnormal motor, sensory and psychic phenomena. Recurrent seizures are usually referred to as EPILEPSY or "seizure disorder."	Absence Seizure,Absence Seizures,Atonic Absence Seizure,Atonic Seizure,Clonic Seizure,Complex Partial Seizure,Convulsion,Convulsions,Convulsive Seizure,Convulsive Seizures,Epileptic Seizure,Epileptic Seizures,Generalized Absence Seizure,Generalized Tonic-Clonic Seizures,Jacksonian Seizure,Myoclonic Seizure,Non-Epileptic Seizure,Nonepileptic Seizure,Partial Seizure,Seizure,Seizures, Convulsive,Seizures, Focal,Seizures, Generalized,Seizures, Motor,Seizures, Sensory,Tonic Clonic Seizure,Tonic Seizure,Tonic-Clonic Seizure,Atonic Absence Seizures,Atonic Seizures,Clonic Seizures,Complex Partial Seizures,Convulsion, Non-Epileptic,Generalized Absence Seizures,Myoclonic Seizures,Non-Epileptic Seizures,Nonepileptic Seizures,Partial Seizures,Petit Mal Convulsion,Seizures, Auditory,Seizures, Clonic,Seizures, Epileptic,Seizures, Gustatory,Seizures, Olfactory,Seizures, Somatosensory,Seizures, Tonic,Seizures, Tonic-Clonic,Seizures, Vertiginous,Seizures, Vestibular,Seizures, Visual,Single Seizure,Tonic Seizures,Tonic-Clonic Seizures,Absence Seizure, Atonic,Absence Seizure, Generalized,Absence Seizures, Atonic,Absence Seizures, Generalized,Auditory Seizure,Auditory Seizures,Clonic Seizure, Tonic,Clonic Seizures, Tonic,Convulsion, Non Epileptic,Convulsion, Petit Mal,Convulsions, Non-Epileptic,Focal Seizure,Focal Seizures,Generalized Seizure,Generalized Seizures,Generalized Tonic Clonic Seizures,Generalized Tonic-Clonic Seizure,Gustatory Seizure,Gustatory Seizures,Motor Seizure,Motor Seizures,Non Epileptic Seizure,Non Epileptic Seizures,Non-Epileptic Convulsion,Non-Epileptic Convulsions,Olfactory Seizure,Olfactory Seizures,Partial Seizure, Complex,Partial Seizures, Complex,Seizure, Absence,Seizure, Atonic,Seizure, Atonic Absence,Seizure, Auditory,Seizure, Clonic,Seizure, Complex Partial,Seizure, Convulsive,Seizure, Epileptic,Seizure, Focal,Seizure, Generalized,Seizure, Generalized Absence,Seizure, Generalized Tonic-Clonic,Seizure, Gustatory,Seizure, Jacksonian,Seizure, Motor,Seizure, Myoclonic,Seizure, Non-Epileptic,Seizure, Nonepileptic,Seizure, Olfactory,Seizure, Partial,Seizure, Sensory,Seizure, Single,Seizure, Somatosensory,Seizure, Tonic,Seizure, Tonic Clonic,Seizure, Tonic-Clonic,Seizure, Vertiginous,Seizure, Vestibular,Seizure, Visual,Seizures, Generalized Tonic-Clonic,Seizures, Nonepileptic,Sensory Seizure,Sensory Seizures,Single Seizures,Somatosensory Seizure,Somatosensory Seizures,Tonic Clonic Seizures,Tonic-Clonic Seizure, Generalized,Tonic-Clonic Seizures, Generalized,Vertiginous Seizure,Vertiginous Seizures,Vestibular Seizure,Vestibular Seizures,Visual Seizure,Visual Seizures