Manganese toxicity is targeting an early step in the dopamine signal transduction pathway that controls lateral cilia activity in the bivalve mollusc Crassostrea virginica.

Manganese is a neurotoxin causing manganism, a Parkinson-like clinical disorder. Manganese has been shown to interfere with dopaminergic neurotransmission, but the neurotoxic mechanism involved is not fully resolved. In the bivalve mollusc Crassostrea virginica also known as the eastern oyster, beating rates of lateral cilia of the gill are controlled by dopaminergic-serotonergic innervation originating from their cerebral and visceral ganglia.

Innervation of Gill Lateral Cells in the Bivalve Mollusc Affects Cellular Membrane Potential and Cilia Activity.

Gill lateral cells of are innervated by the branchial nerve, which contains serotonergic and dopaminergic fibers that regulate cilia beating rate. Terminal release of serotonin or dopamine results in an increase or decrease, respectively, of cilia beating rate in lateral gill cells. In this study we used the voltage sensitive fluorescent probe DiBAC(3) to quantify changes in gill lateral cell membrane potential in response to electrical stimulation of the branchial nerve or to applications of serotonin and dopamine, and correlate these changes to cilia beating rates.

Presence of Octopamine and an Octopamine Receptor in .

Octopamine is a biogenic amine first identified in octopus. It has been well studied in arthropods and a few gastropods, serving as a neurotransmitter and hormone. The presence of octopamine has rarely been reported in bivalves and has not been reported in We utilized HPLC to identify and measure octopamine in cerebral ganglia, visceral ganglia, gill, palps, mantle, heart and hemolymph of Endogenous octopamine levels increased when animals were treated with tyramine, an octopamine precursor.

The Presence of Histamine and a Histamine Receptor in the Bivalve Mollusc, .

Histamine, a biogenic amine, is a neurotransmitter in neurons and sensory receptors in invertebrates. Histamine has rarely been reported in bivalves. We used HPLC with pre-column derivatization using 2,3-naphthalenedicarboxaldehyde (NDA) as a fluorescent labeling agent to measure histamine in ganglia, and peripheral tissues of the oyster .

The Ability of PAS, Acetylsalicylic Acid and Calcium Disodium EDTA to Protect Against the Toxic Effects of Manganese on Mitochondrial Respiration in Gill of Crassostrea virginica.

Manganese (Mn) is an essential metal that at excessive levels in brain causes Manganism, a condition similar to Parkinson's disease. Previously we showed that Mn had a neurotoxic effect on the dopaminergic, but not serotonergic, innervation of the lateral ciliated cells in the gill of the Eastern Oyster, Crassostrea virginica. While the mechanism of action of Mn toxicity is not completely understood, studies suggest that Mn toxicity may involve mitochondrial damage and resulting neural dysfunction in the brain's dopaminergic system.

Identification of dopamine D2 receptors in gill of Crassostrea virginica.

The lateral epithelial cells of gill of Crassostrea virginica are innervated by dopamine and serotonin nerves that regulate the beating rate of their lateral cilia. Terminal release of dopamine slows down the beating rate of the cilia, while serotonin release increases the beating rate. Previously, we showed that the dopaminergic, but not the serotonergic, mechanism regulating the beating rate of the lateral cilia was disrupted by manganese treatments and that this disruption was occurring postsynaptically, at the level of the dopamine receptor or further downstream in the signal transduction pathway.

The Effects of Copper and Copper Blocking Agents on Gill Mitochondrial O(2) Utilization of Crassostrea virginica.

While essential in trace amounts, excess copper is toxic to cells and tissues. Copper is a major aquatic pollutant. Previously, our lab demonstrated that tissues of the bivalve mollusc Crassostrea virginica readily accumulated copper and other metals from their surrounding environment.

Effects of Potential Therapeutic Agents on Copper Accumulations in Gill of Crassostrea virginica.

Copper is an essential trace element for organisms, but when in excess, copper's redox potential enhances oxyradical formation and increases cellular oxidative stress. Copper is a major pollutant in Jamaica Bay and other aquatic areas. Bivalves are filter feeders that accumulate heavy metals and other pollutants from their environment.

Effects of p-Aminosalicylic acid on the neurotoxicity of manganese on the dopaminergic innervation of the cilia of the lateral cells of the gill of the bivalve mollusc, Crassostrea virginica.

The lateral cilia of the gill of Crassostrea virginica are controlled by a dopaminergic-serotonergic innervation. Dopamine is the neurotransmitter causing cilio-inhibition. High levels of manganese are neurotoxic to people, causing Manganism, a Parkinson-like disease.

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Over the next decade, demand and job opportunities in science and engineering (S&E) are expected to grow. With so many S&E "baby-boomers" retiring, questions arise as to whether America will be able to attract enough young people into Science, Technology, Engineering and Mathematics (STEM) to maintain a S&E workforce that keeps up with what is becoming a more globally technologically and scientifically advancing society. Furthermore, considering recent projections of a nation more racially and ethnically diverse by mid-century, will America's future STEM workforce reflect the diversity projected for our growing U.

The neurotoxic effects of manganese on the dopaminergic innervation of the gill of the bivalve mollusc, Crassostrea virginica.

We examined effects of manganese on the nervous system and innervation of lateral cilia of Crassostrea virginica. While essential in trace amounts, tissue manganese accumulation is neurotoxic, inducing Manganism, a Parkinson's-like disease in humans. Lateral cilia of the gill of C.

Effects of p-Aminosalicylic acid on the Neurotoxicity of Manganese and Levels of Dopamine and Serotonin in the Nervous System and Innervated Organs of Crassostrea virginica.

Manganese is a neurotoxin causing Manganism in individuals chronically exposed to elevated levels in their environment. Toxic manganese exposure causes mental and emotional disturbances, and a movement disorder similar to Idiopathic Parkinsons Disease. Manganese interferes with dopamine neurons involved in control of body movements.

Bioaccumulation and Tissue Distribution of Arsenic, Cadmium, Copper and Zinc in Crassostrea virginica Grown at Two Different Depths in Jamaica Bay, New York.

Historically, Jamaica Bay was a site of extensive oyster beds and shellfish culture leases that supported a significant oyster fishery in the New York area. The industrial and urban expansion of the early 1900's led to over-harvesting and a deterioration in water and bay sediment quality that coincided with shellfish decline and the ultimate disappearance of oysters from the bay. Over the past 50 years, efforts to arrest and reverse the pollution problems of Jamaica Bay have been undertaken but the area still contains metals and other pollutants at levels higher than NYS Water Quality Standards.

The nervous system control of lateral ciliary activity of the gill of the bivalve mollusc, Crassostrea virginica.

Lateral cilia of the gill of Mytilus edulis are controlled by a reciprocal serotonergic-dopaminergic innervation from their ganglia. Other bivalves have been studied to lesser degrees and lateral cilia of most respond to serotonin and dopamine when applied directly to the gill indicating a possible neuro or endocrine mechanism. Lateral cilia in Crassostrea virginica are affected by serotonin and dopamine, but little work has been done regarding ganglionic control of their cilia.

Growth and Survival of the American Oyster in Jamaica Bay, New York.

Jamaica Bay is a major inlet opening to the Atlantic Ocean. It was abundant with oysters until early 1900's. Over-harvesting, pressure from predators, parasitic invasion and declining water quality often are cited as causes.