Morphological analyses about origins, neurochemical substances and target-specificily of neurons coming to the subfornical organ

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 14580771
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Neuroscience in general
• Research Institution: Saga University (2004); 佐賀医科大学 (2002-2003)
• Principal Investigator: KAWANO Hitoshi Saga University, Medicine, Associate Professor, 医学部, 助教授 (10152985)
• Co-Investigator(Kenkyū-buntansha): MASUKO Sadahiko Saga University, Medicine, Professor, 医学部, 教授 (20015100)
• Project Period (FY): 2002 – 2004
• Keywords: subfornical organ / nerve inputs / origins / neurochemical substances / axonal transport technique / immunohistochemistry / electron microscopy

Research Abstract

Origins, neurochemical substances and target-specificity of neurons coming to the subfornical organ(SFO) were investigated using anterograde and retrograde tracing technique combined with immunohistochemistry. Distribution and target elements of nerve terminals containing several neurochemical substances were investigated for the basis of the study. There were aminergic, cholinergic and peptidergic nerve terminals in the SFO. Serotonin-,Met-enkephalin-8(mE8)-,galanin(GAL)-,neurotensin- and luteinizing hormone-releasing hormone-immunoreactive nerve terminals made synapses with cell bodies and dendrites, and contacted closely with vessels and glial cells in the SFO. Origins of mE8-immunoreactive projections were the anterodorsal and anteroventral periventricular nuclei, preoptic and hypothalamic periventricular regions, median preoptic nucleus, hypothalamic dorsomedial and arcuate nuclei, medial parabrachial nucleus and solitary nucleus ; GAL-immunoreactive projections were the medial preoptic nucleus, medial parvocellular paraventricular nucleus, hypothalamic periventricular regions, hypothalamic dorsomedial and arcuate nuclei ; bornbesin-immunoreactive projections were the medial parvocellular paraventricular nucleus and rostral ventrolateral medulla ; neuropeptide Y-immunoreactive projections were the hypothalamic arcuate nucleus, solitary nucleus and ventrolateral medulla ; cholinergic projections were the medial septal nucleus and diagonal band. Projections to the SFO from the median preoptic nucleus were huge. They made synapses with cell bodies and dendrites, and contacted closely with vessels and glial cells.
It is very interesting to clear the relationship between SFO neurons projecting to one of the main targets, the paraventricular nucleus and nerve terminals coming from main origins, such as the median preoptic nucleus, lateral parabrachial nucleus and raphe nuclei. This is the matter to be solved.