Effects of 5-hydroxytryptamine on membrane potential, contractility, accumulation of cyclic AMP, and Ca2+ movements in anterior aorta and ventricle of Aplysia

Sawada, Masashi; Ichinose, Mitsuyuki; Ito, Izumi; Maéno, Takashi; McAdoo, David J.

doi:10.1152/jn.1984.51.2.361

Cited by 42 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The function of 5-HT sulfate is independent of 5-HTstimulated increases in the Aplysia heart rate Micromolar concentrations of exogenous 5-HT are sufficient to stimulate or positively modulate beating activity of the Aplysia heart via a cAMP-mediated signaling pathway (Liebeswar et al 1975;Mandelbaum et al 1979;Sawada et al 1984). Here, isolated Aplysia hearts were transferred to 5-mL Petri dishes containing experimental solutions in the following order: i) ASW; ii) 50 lM 5-HT; iii) ASW; iv) 100 lM 5-HT sulfate; and v) 45 lM 5-HT + 100 lM 5-HT sulfate.…”

Section: -Ht and 5-ht Sulfate Exhibit Marked Differences In Functionmentioning

confidence: 99%

Systemic serotonin sulfate in opisthobranch mollusks

Stuart¹,

Ebaugh²,

Copes³

et al. 2004

Journal of Neurochemistry

View full text Add to dashboard Cite

Serotonin (5-hydroxytryptamine, 5-HT) is a ubiquitous modulatory neurotransmitter with roles as a neurohormone and neurotransmitter. However, few studies have been performed characterizing this molecule and its related metabolites in circulating fluids. Here, we demonstrate native 5-HT sulfate, but much lower levels of 5-HT, in hemolymph of the marine mollusk Pleurobranchaea californica. The metabolite 5-HT sulfate forms from 5-HT uptake and metabolism in central ganglia of Aplysia californica and in the visceral nerve and eye of Pleurobranchaea, but not in hemolymph itself. In addition, 5-hydroxyindole acetic acid (5-HIAA), while not detected in hemolymph, forms in higher quantities than does 5-HT sulfate in the eye and visceral nerve, and c-glu-5-HT is also observed in this area but never in hemolymph. As systemic 5-HT sulfate appears not to originate from the optic region or from systemic 5-HT, 5-HT sulfate likely derives from the nervous system. Circulating 5-HT sulfate is at least 10-fold higher during the light portion of a 12 : 12-h light/dark cycle than during the dark portion (p < 0.0007), but there is no obvious trend for free systemic tryptophan (Trp) (p > 0.3) in Pleurobranchaea. 5-HT in mollusks is associated with general arousal state; thus, diurnal systemic changes in a 5-HT catabolite may reflect a regulatory role for indole catabolism in behavioral rhythms. Keywords: capillary electrophoresis, hemolymph, marine mollusk, serotonin, sulfation. Serotonin (5-hydroxytryptamine, 5-HT) is a biogenic amine responsible for a variety of tasks in the nervous system. For instance, 5-HT is implicated in learning and memory in the central nervous system (CNS) and emesis and peristaltic reflex in the enteric nervous system (ENS) (Bartsch et al. 2000;Buhot et al. 2000;Endo et al. 2000). Several organs serve as targets for 5-HT, but the fate of 5-HT in target tissues, let alone the physiological effects of the resulting metabolites, has not been fully ascertained. Knowledge of the products of transformed 5-HT, as well as their distribution patterns, will assist in illuminating the processes leading to impaired neurotransmission and eventually aid in designing compounds that could potentially inhibit disease in neural and surrounding tissues.Marine mollusks present an excellent model for the study of the nervous system because of their large cell somata and well-characterized neural networks. In gastropod mollusks, 5-HT is involved in many neurophysiological processes, including sensitization and facilitation of withdrawal reflexes (Hawkins et al. 1993), feeding behavior (Gillette and Davis 1977) and locomotion (McPherson and Blankenship 1991). However, 5-HT-related metabolites have received considerably less attention.Our laboratory recently demonstrated that 5-HT metabolism in Aplysia californica involves sulfation and c-glutamylation with trace amounts of monoamine oxidase activity present in the form of 5-hydroxyindole acetic acid (5-HIAA) (Stuart et al. 2003). In particular, 5-HT sulfate is present ...

show abstract

Section: -Ht and 5-ht Sulfate Exhibit Marked Differences In Functionmentioning

confidence: 99%

Systemic serotonin sulfate in opisthobranch mollusks

Stuart¹,

Ebaugh²,

Copes³

et al. 2004

Journal of Neurochemistry

View full text Add to dashboard Cite

show abstract

“…5-HT and the metacerebral cell do not themselves induce contraction, and they do not act primarily by enhancing EJPs or changing the membrane permeability. cAMP appears to be involved in the action of 5-HT on the radula muscle and on the anterior aorta (SAWADA et al, 1984b). However, glycine does not increase cAMP levels in the AA, so the actions of glycine are not mediated by increased intracellular levels of cAMP.…”

Section: Discussionmentioning

confidence: 93%

“…Glycine does not detectably influence spontaneous EJP amplitude or frequency, contrary to what might be expected for the effect on the transmitter release. In addition, contractions induced by bath applied 5-HT, a probable excitatory neurotransmitter to the anterior aorta (SAWADA et a!., 1984b), were also enhanced by glycine and R14 activity.…”

Section: Discussionmentioning

confidence: 93%

“…Ca2+ efflux was measured as previously (SAWADA et a!., 1984b) utilizing the method of DETH and CASTEELS (1977). Opened anterior aortas and ventricles were incubated for 2 hr in ASW containing approximately 4 µCilml of 45Ca2+.…”

Section: Methodsmentioning

confidence: 99%

“…D. J. MCADOO, M. ICHINOSE, and C. H. PRICE enhance the stimulated contractions. Pulses of 0.01 mM 5-hydroxytryptamine, a probable neurotransmitter to the anterior aorta (SAWADA et al, 1984b), cause rhythmic contraction of the anterior aorta with the vulvar nerve severed. The amplitude of these 5-HT induced contractions was increased 30% by 1.0 mM glycine (Fig.…”

Section: Effect Of Glycine On Contraction Of the Anterior Aortamentioning

confidence: 99%

See 2 more Smart Citations

Influences of glycine and neuron R14 on contraction of the anterior aorta of Aplysia.

Sawada¹,

McAdoo²,

Ichinose³

et al. 1984

Jpn.J.Physiol

View full text Add to dashboard Cite

Firing neuron R14 in the Aplysia parietovisceral ganglion enhances the force of stimulated contractions and causes rhythmic contractions rather than individual contractions in response to a single stimulation of the anterior aorta of Aplysia. Bath application of 1.0 mM glycine to the artery causes a small depolarization, rhythmic contractions and enhances the force of individual, neurally induced contractions of the anterior aorta. These observations suggest that the physiological role of the innervation of the anterior aorta by R14 is to convert the mode of contraction of the anterior aorta from direct neural control to a myogenic mode. R14 activity does not produce classical junction potentials and inotophoretically applied glycine does not produce detectable potential changes in the anterior aorta muscle fibers. Glycine increases the force and frequency of Aplysia heart beat, and blood pressure. Glycine causes release of preloaded Ca2+ from the ventricle of the Aplysia heart, implying that glycine causes intracellular release of Cat+. The similarity of the actions of glycine and electrical activity in R14 extend previous evidence that R14 may utilize glycine to modulate the contractility of Aplysia circulatory muscle.

show abstract

Anatomy and innervation of the anterior aorta of Aplysia and the ultrastructure of specialized neuromuscular junctions on vascular smooth muscle

Price

Fowle

Rittenhouse

1984

J of Comparative Neurology

View full text Add to dashboard Cite

The fine structure of the cellular layers and innervation of smooth muscle in the anterior aorta of Aplysia were examined. The inner layer of circular muscle is not innervated but its fibers may be electrically coupled. In contrast, longitudinal fibers in the outer layer are well separated and richly innervated by highly specialized neuromuscular junctions (NMJ). Three distinct types of NMJ are present on this smooth muscle, each identifiable by a set of quantitatively described morphological features including size, degree of contact with sarcolemma, density of active zones, number of mitochondria and vesicular content. The three types of NMJ are likely to arise from the identified serotonergic (RDAAE), cholinergic (RDAAI), and glycinergic (R14) neurons that provide the major known excitatory, inhibitory, and modulatory inputs to this vessel. Each longitudinal muscle fiber is separately innervated by one or more NMJ of each type. Since there are no intercellular junctions between longitudinal fibers, coordination of contractility is clearly a function of the pattern of neural activity. This report further characterizes the rapid and fine control of the vasculature in Aplysia and demonstrates the utility of this preparation for cellular-level studies on the neural control of smooth muscle and neurochemical messengers mediating its activity.

show abstract

Effects of 5-hydroxytryptamine on membrane potential, contractility, accumulation of cyclic AMP, and Ca2+ movements in anterior aorta and ventricle of Aplysia

Cited by 42 publications

References 0 publications

Systemic serotonin sulfate in opisthobranch mollusks

Systemic serotonin sulfate in opisthobranch mollusks

Influences of glycine and neuron R14 on contraction of the anterior aorta of Aplysia.

Anatomy and innervation of the anterior aorta of Aplysia and the ultrastructure of specialized neuromuscular junctions on vascular smooth muscle

Contact Info

Product

Resources

About