Dopaminergic phenotype

Saucedo-Cardenas O, Quintana-Hau JD, Le WD, Smidt MP, Cox JJ, DeMayo F, Burbach JPH, Conneely OM (1998) Nurrl is essential for the induction of the dopaminergic phenotype and the survival of ventral mesencephalic late dopaminergic precursor neurons. Proc Natl Acad Sci USA 95 4013 1018. 

Zhou, J., Bradford, H.F. and Stem, G.M. (1994) The stimulatory effect of brain-derived neurotrophic factor on dopaminergic phenotype expression of embryonic rat cortical neurons in vitro. Dev. Brain Res. 81 318-324. 

The most dramatic phenotype in NRTN knockout mice is a breathing defect due to loss of about half of the neurons in the petrosal ganglia. NRTN can support both dopaminergic neurons and spinal motor neurons in vitro,... 

Dopamine is synthesized from the amino acid tyrosine by the enzymes tyrosine hydroxylase (TH which forms L-3,4-dihydroxylphenylalanine, l-DOPA) and L-amino acid decarboxylase (AADC) in dopaminergic neurons. The mRNA expression of the TH (which is the rate-limiting enzyme in the synthesis of dopamine) is abundant throughout the human mesencephalon (Fig. 1) TH is a phenotypic marker for all catecholamines, dopamine, noradrenaline and adrenaline. Evidence for the presence of TH has been documented in the mesencephalon from at least 4.5 to 7 weeks of human fetal life... 

A mouse spontaneous deletion strain is viable, fertile, and phenotypically normal (Specht and Schoepfer, 2001) whereas overexpression of wild-type SNCA in a mouse model has many features of PD, such as loss of dopaminergic terminals in the striatum, mislocalization and accumulation of insoluble a-synuclein, and motor abnormalities (Rockenstein et al., 2002 Fleming et al., 2004 Masliah et al., 2000). Both A30P and A53T mutant mouse models display neuronal cell loss and motor changes (Melrose et al., 2006). 

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