Biology Reference
In-Depth Information
CHAPTER FOUR
The Role of Serotonin in Axon
and Dendrite Growth
Ephraim F. Trakhtenberg
1
, Jeffrey L. Goldberg
1
Bascom Palmer Eye Institute, Interdisciplinary Stem Cell Institute, Neuroscience Program, University of
Miami Miller School of Medicine, Miami, FL 33136
1
Corresponding author: e-mail address: etrakhtenberg@med.miami.edu; JGoldberg@med.miami.edu
Contents
1.
Introduction
106
2. 5-HT Affects Neurite Growth
106
2.1 Invertebrates and lower vertebrates
106
2.2 Mammals
107
3. 5-HT Receptors Subtypes Affecting Neurite Growth
108
3.1 Htr1A
109
3.2 Htr1B/D
110
3.3 Htr2A/C
110
3.4 Htr3
111
3.5 Htr4/5/7
112
4. Mechanisms of 5-HT Effect on Neurite growth
113
5. Discussion
114
6. Conclusion
120
Acknowledgments
121
References
121
Abstract
The neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) plays multiple roles in the
enteric, peripheral, and central nervous systems (CNS). Although its most prominent
biological function is as a signal transmission messenger from pre- to postsynaptic neu-
rons, other roles such as shaping brain development and regulating neurite growth
have also been described. Here, we review the less well-studied role of 5-HT as a mod-
ulator of neurite growth. 5-HT has been shown to regulate neurite growth in multiple
systems and species, including in the mammalian CNS. 5-HT predominantly appears to
suppress neurite growth, but depending on the model system and 5-HT receptor sub-
type, in rare cases, it may promote neurite outgrowth and elongation. Failure of axon
regeneration in the adult mammalian CNS is a major problem in multiple diseases, and
understanding how 5-HT receptors signal opposing effects on neurite growth may lead
to novel neuroregenerative therapies, by targeting either 5-HT receptors or their down-
stream signaling pathways.
