Sensitivity of Serotonin Synthesis to Synthesis Inhibitor GTP Cyclohydrolase I in Senescence-Accelerated Mouse-Prone Inbred Strain (SAMP8)

Abstract

To study the relationship between aging and levels of monoaminergic neurons, 2,4-diamino-6-hydroxypyrimidine (DAHP), an inhibitor of monoamine synthesis, was intraperitoneally administered to senescence-accelerated mouse-prone (SAMP8) mice. Time course of immunoreactive intensity for serotonergic (5-HT) neurons in the dorsal raphe nucleus, which were stained using laboratory-raised serotonin-specific antibody, was quantitatively evaluated using an image analysis system. Results showed that 5-HT neurons are not highly sensitive to a synthesis inhibitor common to both catecholaminergic and 5-HT neurons.