Many of the phenolic acids in human urine have been characterized, and several have been tentatively identified by means of their behavior on paper chromatograms (3). Further studies have revealed that most of them originate from dietary precursors, but a few have been found to be excreted always and in amounts which are relatively constant for a given individual despite marked changes in the d...

Revealing reinforcing mechanisms in associative learning is important for elucidation of brain mechanisms of behavior. In mammals, dopamine neurons are thought to mediate both appetitive and aversive reinforcement signals. Studies using transgenic fruit-flies suggested that dopamine neurons mediate both appetitive and aversive reinforcements, through the Dop1 dopamine receptor, but our studies ...

Although crustaceans typically have a neurogenic heart, the primitive crustacean Triops longicaudatus has a myogenic heart with the heartbeat arising from the endogenous rhythmic activity of the myocardium. In the present investigation, the effects of six biogenic amines, epinephrine, norepinephrine, dopamine, octopamine, serotonin and histamine, on the myogenic heart of T. longicaudatus were e...

Using pairings of male crayfish Procambarus clarkii with a 3-7% difference in size, we confirmed that physically larger crayfish were more likely to win encounters (winning probability of over 80%). Despite a physical disadvantage, small winners of the first pairings were more likely to win their subsequent conflicts with larger naive animals (winning probability was about 70%). By contrast, th...

In this communication we report that four substances, thought to function as neurohormones in Crustacea, all produce long-term changes in the physiological properties of lobster opener muscle preparations. The substances are the amines, octopamine, serotonin and dopamine, and the peptide, proctolin. The actions of these substances are superimposed on the normal synaptic apparatus that utilizes ...

The purpose of this contribution is to review our current understanding of the source and biochemistry of the circadian efferent input to the eyes of the American horseshoe crab Limulus polyphemus and the impact of this input on the structure, physiology and biochemistry of Limulus eyes. Special emphasis is given to the role of the biogenic amine octopamine and biochemical cascades it activates...

The musculature of the colleterial glands receives innervation from branch 4B4a of the nerves designated 4B, which arise from the posterior part of the terminal abdominal ganglion in the female cockroach Periplaneta americana (L). Using Methylene Blue staining, the gross anatomy of the colleterial gland innervation has been described. Cobalt backfilling via branch 4B4 of nerve 4B revealed about...

Serotonin and octopamine have opposite effects on a simple behavioral response, the crayfish's lateral giant escape reaction. Specifically, serotonin depresses the lateral giants' responsiveness, whereas octopamine enhances it. Both effects are largely confined to the disynaptic pathway from the sensory afferents to the lateral giants, although, occasionally, small effects are also seen in the ...

Chemosensory pheromonal information regulates aggression and reproduction in many species, but how pheromonal signals are transduced to reliably produce behavior is not well understood. Here we demonstrate that the pheromonal signals detected by Gr32a-expressing chemosensory neurons to enhance male aggression are filtered through octopamine (OA, invertebrate equivalent of norepinephrine) neuron...

The Seville orange extract Citrus aurantium contains m-synephrine (phenylephrine) and octopamine; it causes cardiac disturbances in animals and is used by humans for weight loss. Juice from the orange (Seville orange juice [SOJ]) is used to "knock out" intestinal cytochrome P450 (CYP) 3A4 in bioavailability studies. The purpose of this study was to determine synephrine and octopamine concentrat...