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Enzyme

Amine

Acetylcholine Biogenic amine Dopamine Norepinephrine

Epinephrine

Indoleamine Serotonin Amino acid Glutamate GABA Glycine Membrane soluble Nitric oxide Arachidonic acid

Cholineacetyl transferase

Tyrosine hydroxylase Tyrosine hydroxylase Dopamine b-hydroxylase Tyrosine hydroxylase Dopamine b-hydroxylase Phentolamine- N methyltransferase

Tryptophan hydroxylase

Glutamic acid decarboxylase

Nitric oxide synthase

Henry H. Dale. By the middle of the twentieth century, ideas about neurotransmitters were based almost entirely on experiments with these two small-molecule transmitters.

Another group of small-molecule transmitters, the purines, is derived from adenosine triphosphate (ATP). Like the amine transmitters, ATP is not made within the tubules of the endoplasmic reticulum or in the stacks of the Golgi apparatus, but in mitochondria. How then do the amine transmitters and ATP get into vesicles, typically in rather high concentrations (0.010.5 M)? The answer is that membranes of vesicles contain special pumps that effectively transport small-molecule transmitters into the lumen of the vesicle. Because all transmitter vesicles contain ATP, when a transmitter is released, ATP and its catabolites, adenosine and AMP, are also released. Finally, the most recent substances to be recognized as transmitters are molecules that are membrane-soluble. Thus, nitric oxide (NO) and arachidonic acid pass from one neuron to another.

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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