Effects of midbrain raphe lesions or systemic p-chlorophenylalanine on the development of kindled seizures in rats. 1979

R Racine, and D V Coscina

Previous research has suggested that brain serotonin (5-hydroxytryptamine or 5-HT) neurons inhibit epileptiform seizure activity. To test further this possibility, experiments were performed to determine if brain 5-HT depletion would enhance the occurrence and/or magnitude of seizures "kindled" from the amygdala or neocortex of rats. Two modes of 5-HT depletion were used: (1) radiofrequency heat lesions of the midbrain dorsal and median raphe nuclei, and (2) systemic injection of the 5-HT synthesis inhibitor, p-chlorophenylalanine (pCPA). Both modes of 5-HT depletion reliably enhanced the strength of motor convulsions kindled from the cortex. Systemic pCPA also reduced the duration of after-discharges (ADs) in cortically-stimulated rats. However, pCPA reduced rather than enhanced convulsions kindled from the amygdala. In contrast to this, raphe lesions appeared to sensitize rats to the effects of amygdaloid kindling, i.e., lesions lowered AD thresholds, AD durations and number of ADs to elicit motor convulsions. Viewed together, these data support the hypothesis that 5-HT neurons can serve to inhibit seizures. However, the lack of robustness across parameters of epileptogenesis as well as discrepant findings related to 5-HT depletion mode additionally suggest that kindled seizures affect other neuronal populations in addition to those under serotonergic influence.

UI MeSH Term Description Entries
D007274 Injections, Intraperitoneal Forceful administration into the peritoneal cavity of liquid medication, nutrient, or other fluid through a hollow needle piercing the abdominal wall. Intraperitoneal Injections,Injection, Intraperitoneal,Intraperitoneal Injection
D008297 Male Males
D009412 Nerve Fibers Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM. Cerebellar Mossy Fibers,Mossy Fibers, Cerebellar,Cerebellar Mossy Fiber,Mossy Fiber, Cerebellar,Nerve Fiber
D009434 Neural Pathways Neural tracts connecting one part of the nervous system with another. Neural Interconnections,Interconnection, Neural,Interconnections, Neural,Neural Interconnection,Neural Pathway,Pathway, Neural,Pathways, Neural
D010134 Fenclonine A selective and irreversible inhibitor of tryptophan hydroxylase, a rate-limiting enzyme in the biosynthesis of serotonin (5-HYDROXYTRYPTAMINE). Fenclonine acts pharmacologically to deplete endogenous levels of serotonin. p-Chlorophenylalanine,para-Chlorophenylalanine,CP-10,188,DL-3-(4-Chlorophenyl)alanine,Fenclonin,Fenclonine (L)-Isomer,Fenclonine Hydrobromide,Fenclonine Hydrochloride,Fenclonine, (D)-Isomer,Hydrobromide, Fenclonine,Hydrochloride, Fenclonine,para Chlorophenylalanine
D011903 Raphe Nuclei Collections of small neurons centrally scattered among many fibers from the level of the TROCHLEAR NUCLEUS in the midbrain to the hypoglossal area in the MEDULLA OBLONGATA. Caudal Linear Nucleus of the Raphe,Interfascicular Nucleus,Nucleus Incertus,Rostral Linear Nucleus of Raphe,Rostral Linear Nucleus of the Raphe,Superior Central Nucleus,Central Nucleus, Superior,Incertus, Nucleus,Nuclei, Raphe,Nucleus, Interfascicular,Nucleus, Raphe,Nucleus, Superior Central,Raphe Nucleus
D001933 Brain Stem The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA. Brainstem,Truncus Cerebri,Brain Stems,Brainstems,Cerebri, Truncus,Cerebrus, Truncus,Truncus Cerebrus
D004558 Electric Stimulation Use of electric potential or currents to elicit biological responses. Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
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
D000679 Amygdala Almond-shaped group of basal nuclei anterior to the INFERIOR HORN OF THE LATERAL VENTRICLE of the TEMPORAL LOBE. The amygdala is part of the limbic system. Amygdaloid Body,Amygdaloid Nuclear Complex,Amygdaloid Nucleus,Archistriatum,Corpus Amygdaloideum,Intercalated Amygdaloid Nuclei,Massa Intercalata,Nucleus Amygdalae,Amygdalae, Nucleus,Amygdaloid Bodies,Amygdaloid Nuclear Complices,Amygdaloid Nuclei, Intercalated,Amygdaloid Nucleus, Intercalated,Amygdaloideum, Corpus,Amygdaloideums, Corpus,Archistriatums,Complex, Amygdaloid Nuclear,Complices, Amygdaloid Nuclear,Corpus Amygdaloideums,Intercalata, Massa,Intercalatas, Massa,Intercalated Amygdaloid Nucleus,Massa Intercalatas,Nuclear Complex, Amygdaloid,Nuclear Complices, Amygdaloid,Nuclei, Intercalated Amygdaloid,Nucleus, Amygdaloid,Nucleus, Intercalated Amygdaloid

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