@article {136,
	title = {Activity-dependent expression of Lmx1b regulates specification of serotonergic neurons modulating swimming behavior.},
	journal = {Neuron},
	volume = {67},
	year = {2010},
	month = {2010 Jul 29},
	pages = {321-34},
	abstract = {<p>Genetic programs, environmental factors, and electrical activity interact to drive the maturation of the brain. Although the cascade of transcription factors that leads to specification of the serotonergic phenotype has been well characterized, its interactions with electrical activity are not known. Here we show that spontaneous calcium spike activity in the hindbrain of developing Xenopus laevis larvae modulates the specification of serotonergic neurons via regulation of expression of the Lmx1b transcription factor. Activity acts downstream of Nkx2.2 but upstream of Lmx1b, leading to regulation of the serotonergic phenotype. Using global manipulation of activity and targeted alteration of Lmx1b expression, we also demonstrate that changes in the number of serotonergic neurons change larval swimming behavior. The results link activity-dependent regulation of a transcription factor to transmitter specification and altered behavior.</p>
},
	keywords = {Action Potentials, Animals, Behavior, Animal, Bromodeoxyuridine, Calcium, Electroporation, Embryo, Nonmammalian, gamma-Aminobutyric Acid, Gene Expression Regulation, Developmental, Green Fluorescent Proteins, Homeodomain Proteins, Membrane Potentials, Neurons, Otx Transcription Factors, Potassium Channels, Inwardly Rectifying, Raphe Nuclei, RNA, Messenger, Serotonin, Sodium Channels, Statistics, Nonparametric, Swimming, Transcription Factors, Tryptophan Hydroxylase, Xenopus laevis, Xenopus Proteins},
	issn = {1097-4199},
	doi = {10.1016/j.neuron.2010.06.006},
	author = {Demarque, Micha{\"e}l and Spitzer, Nicholas C}
}
@article {132,
	title = {Embryonically expressed GABA and glutamate drive electrical activity regulating neurotransmitter specification.},
	journal = {J Neurosci},
	volume = {28},
	year = {2008},
	month = {2008 Apr 30},
	pages = {4777-84},
	abstract = {<p>Neurotransmitter signaling in the mature nervous system is well understood, but the functions of transmitters in the immature nervous system are less clear. Although transmitters released during embryogenesis regulate neuronal proliferation and migration, little is known about their role in regulating early neuronal differentiation. Here, we show that GABA and glutamate drive calcium-dependent embryonic electrical activity that regulates transmitter specification. The number of neurons expressing different transmitters changes when GABA or glutamate signaling is blocked chronically, either using morpholinos to knock down transmitter-synthetic enzymes or applying pharmacological receptor antagonists during a sensitive period of development. We find that calcium spikes are triggered by metabotropic GABA and glutamate receptors, which engage protein kinases A and C. The results reveal a novel role for embryonically expressed neurotransmitters.</p>
},
	keywords = {Animals, Antigens, CD57, Calcium, Choline O-Acetyltransferase, Embryo, Nonmammalian, Enzyme Inhibitors, Excitatory Amino Acid Antagonists, GABA Antagonists, gamma-Aminobutyric Acid, Gene Expression Regulation, Developmental, Glutamate Decarboxylase, Glutamic Acid, Health Services Research, Larva, Morpholines, Neurons, Phosphoserine, Receptors, GABA, Receptors, Glutamate, Synapses, Vesicular Glutamate Transport Proteins, Xenopus},
	issn = {1529-2401},
	doi = {10.1523/JNEUROSCI.4873-07.2008},
	author = {Root, Cory M and Vel{\'a}zquez-Ulloa, Norma A and Monsalve, Gabriela C and Minakova, Elena and Spitzer, Nicholas C}
}
