1997 Fiscal Year Final Research Report Summary
The neuronal control of the infrared sensors.
Project/Area Number |
08672028
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Ophthalmology
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Research Institution | Yokohama City University |
Principal Investigator |
AMEMIYA Fumiaki Yokohama City University School of Medicine, Associate Professor, 医学部, 助教授 (50231999)
|
Project Period (FY) |
1996 – 1997
|
Keywords | infrared / receptors / pit vipers / pit membrane / immunohistochemistry / microvasculature / electron microscopy / blood flow meter |
Research Abstract |
We have investigated the neuronal contol of the infrared sensory membranes in the pit organs of pit vipers. 1.We found the surface of the epithelium in the membrane to be covered with a characteristic array of tiny pores, and the inner chamber wall to be sculpted into an extensive array of large and small domed structures. We also used scanning electron microscopy to provide the first three-dimensional views of the infrared receptors, thus giving new evidence of the spatial arrangement of the receptors in a monolayr array. 2.We found substance P (SP) and calcitonin-gene related peptide (CGRP) in unmyelinated nerve fibers inside the pit membrane, and vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) around but outside the membrane. The former peptides are believed to dilate the capillaries inside the membrane and the latter are believed to dilate or constrict the arterioles outside the membrane. 3.Good visualization of the membrane vasculature was obtained with both ink and resin injection. Arterioles, venules, and capillaries could be distinguished. The monolayr vasculature was denser in the pit membrane than in the retina or skin. Each loop of the network enclosed a small number of infrared receptors so that all receptors were in contact with a capillary on at least one side. The forward-looking areas of the pit membrane had a denser network than side-looking areas. We used a laser blood flow meter to demonstrate that the blood flow to the pit membrane through the entering arterioles was increased by a heat stimulus. The flow at the heat-stimulated area decreased because the capillary network dilated locally, whereas the flow in the rest of the membrane increased as blood was drawn into the dilated area.
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Research Products
(4 results)