Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2008 Mar;104(5):1358-63.
doi: 10.1111/j.1471-4159.2007.05084.x. Epub 2007 Nov 23.

5-HT and 5-HT-SO4, but not tryptophan or 5-HIAA levels in single feeding neurons track animal hunger state

N G Hatcher  1 , X Zhang, J N Stuart, L L Moroz, J V Sweedler, R Gillette
Affiliations
Comparative Study

5-HT and 5-HT-SO4, but not tryptophan or 5-HIAA levels in single feeding neurons track animal hunger state

N G Hatcher et al. J Neurochem. 2008 Mar.

Abstract

Serotonin (5-HT) is an intrinsic modulator of neural network excitation states in gastropod molluscs. 5-HT and related indole metabolites were measured in single, well-characterized serotonergic neurons of the feeding motor network of the predatory sea-slug Pleurobranchaea californica. Indole amounts were compared between paired hungry and satiated animals. Levels of 5-HT and its metabolite 5-HT-SO4 in the metacerebral giant neurons were observed in amounts approximately four-fold and two-fold, respectively, below unfed partners 24 h after a satiating meal. Intracellular levels of 5-hydroxyindole acetic acid and of free tryptophan did not differ significantly with hunger state. These data demonstrate that neurotransmitter levels and their metabolites can vary in goal-directed neural networks in a manner that follows internal state.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Single cell wavelength-resolved fluorescence capillary electropherograms from metacerebral giant neurons of paired hungry (upper) and satiated animals (lower). Besides the identifiable compounds 5-HT, 5-hydroxyindole acetic acid (5-HIAA), serotonin sulfate and tryptophan (Trp), a broad band of fluorescence emission represents Trp- and Tyrosine-containing proteins with an intensity that varied from animal to animal but did not significantly correlate with hunger state. Slight differences in analyte position (e.g., 5-HIAA) between electropherograms result from small differences in flow rate between runs. The color scale shows relative intensity of fluorescence emission (scale bar on right).
Fig. 2
Fig. 2
Histograms of (a) serotonin (5-HT), (b) tryptophan (Trp), (c) serotonin sulfate (5-HT-SO4), and (d) 5-hydroxyindole acetic acid (5- HIAA) levels from metacerebral giant neurons of hungry and satiated animal pairs. 5-HT-SO4 levels are presented as fluorescence intensities (arbitrary units). Hungry animals had significantly higher levels of 5-HT and 5-HT-SO4 than their satiated partners, while neither 5-HIAA nor Trp tracked hunger status. *p < 0.008, two-tailed paired t-test; **p = 0.003, two-tailed paired t-test.
See this image and copyright information in PMC

References

    1. Arshavsky YI, Deliagina TG, Gamkrelidze GN, Orlovsky GN, Panchin YV, Popova LB, Shupliakov OV. Pharmacologically induced elements of the hunting and feeding behavior in the pteropod mollusk Clione limacina. I. Effects of GABA. J Neurophysiol. 1993;69:512–521. - PubMed
    1. Berry MS, Pentreath VW. Properties of a symmetric pair of serotonin-containing neurones in the cerebral ganglia of Planorbis. J Exp Biol. 1976;65:361–380. - PubMed
    1. Croll RP, Albuquerque T, Fitzpatrick L. Hyperphagia resulting from gut denervation in the sea slug Pleurobranchaea. Behav Neural Biol. 1987;47:212–218. - PubMed
    1. Davis WJ, Mpitsos GJ, Pinneo JM. The behavioral hierarchy of Pleurobranchaea. I. The dominant position of the feeding behavior. J Comp Physiol. 1974;90:207–224.
    1. Davis WJ, Gillette R, Kovac MP, Croll RP, Matera E. Organization of synaptic inputs to paracerebral feeding command interneurons of Pleurobranchaea californica III. Modifications induced by experience. J Neurophysiol. 1983;49:1557–1572. - PubMed

Publication types