Brain 5-hydroxytryptamine level,metabolism, and binding in E1 mice

Inbred E1 mice are highly susceptible to convulsive seizures upon “throwing” stimulation. The strain is known to have an abnormal 5-hydroxytryptamine (5-HT) metabolism. In the study here 5-HT level, ¹⁴C]5-hydroxytryptophan (5-HTP) metabolism, MAO activity and ³H]5-HT receptor binding were examined in the cortex, brainstem and cerebellum. In the interictal period cortical and brainstem 5-HT level and ³H]5-HT receptor binding were significantly lower. In the same period cortical biosynthesized ¹⁴C]5-HT from ¹⁴C]5-HTP taken up was higher, and MAO activity was not changed.L-DOPA with MK486 induced a low threshold of seizures and decreased cortical 5-HT level. Abnormally functioning 5-HT neurones may exist in the E1 mouse cortex.