Suppressive effects of L-5-hydroxytryptophan in a feline model of photosensitive epilepsy.

Abstract

We recently demonstrated that long-lasting photosensitivity is acquired as a result of kindling of the lateral geniculate nucleus (LGN), and that the LGN-kindled cat pretreated with D, L-allylglycine represents a useful model of epilepsy for drug studies. The present experiments studied anticonvulsant effects of a serotonin precursor, L-5-hydroxytryptophan (5-HTP), on photosensitivity in the LGN-kindled cat under D,L-allylglycine and on LGN-kindled seizures. 5-HTP suppressed both myoclonic responses and paroxysmal EEG discharges induced by photic stimulation in a dose-related manner. Photically-induced seizures were completely blocked 1.5-2 h after injection of 20 mg/kg 5-HTP. 5-HTP was also effective in reducing the afterdischarge duration and behavioral seizure stage in LGN-kindled seizures; following 40 mg/kg administration, no electroclinical seizures were elicited in the LGN-kindled cats. Serotonergic mechanisms may play an important role in epileptic photosensitivity; the 5-HTP suppressive effect on photosensitivity is at least partly due to reduced neuronal activity at the level of the LGN via serotonergic inhibition.

• Authors: Y Wada, H Hasegawa, M Nakamura, N Yamaguchi
• Journal: Brain research (Brain Res) Vol. 552 Issue 1 Pg. 8-12 (Jun 21 1991) ISSN: 0006-8993 [Print] Netherlands
• PMID: 1913184 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Allylglycine
• 5-Hydroxytryptophan

Topics

• 5-Hydroxytryptophan (pharmacology, therapeutic use)
• Allylglycine (pharmacology)
• Animals
• Cats
• Electric Stimulation
• Electroencephalography (drug effects)
• Female
• Geniculate Bodies (drug effects, physiology, physiopathology)
• Hippocampus (drug effects, physiology, physiopathology)
• Kindling, Neurologic
• Male
• Photic Stimulation
• Reticular Formation (drug effects, physiology, physiopathology)
• Seizures (etiology, physiopathology, prevention & control)