The main goal of the proposed research is to elucidate the nature and mechanism of the changes in the physical properties of the collagenous articular capsule, or ligament, that surrounds the spine-test joint of the primary spines of the sea urchin Eucidaris tribuloides. Under the influence of the nervous system the consistency of this ligament can change rapidly and reversibly between two extreme conditions: soft, i.e. extensible, and stiff, or inextensible. Acetylcholine (ACh) consistently stiffens the ligament and may be regarded as the putative catch-inducing neurotransmitter. Pharmacological techniques will be used to search for neurotransmitters or drugs which may induce simple softening and to describe their interactions with ACh. Electron microscopy of conventional preparations and of material stained with cuprolinic blue will be used to characterize cross-links between collagen fibrils and columns and to detect possible alterations in the arrangement of the proteoglycans associated with changes in mechanical properties. In addition, histochemical techniques, using fluorescent phalloidin, anti- actin antibodies and the decoration of actin filaments with heavy meromyosin, will be employed to test the possible presence of actin filaments in the ligament matrix.

Project Start
2001-05-01
Project End
2002-04-30
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
33
Fiscal Year
2001
Total Cost
$243,516
Indirect Cost
Name
University of Puerto Rico Med Sciences
Department
Type
DUNS #
City
San Juan
State
PR
Country
United States
Zip Code
00936
Delgado, Nadia; Vallejo, Deborah; Miller, Mark W (2012) Localization of serotonin in the nervous system of Biomphalaria glabrata, an intermediate host for schistosomiasis. J Comp Neurol 520:3236-55
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Diaz-Rios, Manuel; Oyola, Eduardo; Miller, Mark W (2002) Colocalization of gamma-aminobutyric acid-like immunoreactivity and catecholamines in the feeding network of Aplysia californica. J Comp Neurol 445:29-46
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