title: Expression of the striatal DARPP-32/ARPP-21 phenotype in GABAergic neurons requires neurotrophins in vivo and in vitro.
abstract: The medium spiny neuron (MSN) is the major output neuron of the caudate nucleus and uses GABA as its primary neurotransmitter. A majority of MSNs coexpress DARPP-32 and ARPP-21, two dopamine and cyclic AMP-regulated phosphoproteins, and most of the matrix neurons express calbindin. DARPP-32 is the most commonly used MSN marker, but previous attempts to express this gene in vitro have failed. In this study we found that DARPP-32 is expressed in <12% of E13- or E17-derived striatal neurons when they are grown in defined media at high or low density in serum, dopamine, or Neurobasal/N2 (Life Technologies), and ARPP-21 is expressed in <1%. The percentage increases to 25% for DARPP-32 and 10% for ARPP-21 when the same cells are grown in Neurobasal/B27 (Life Technologies) for 7 d. After growth in Neurobasal/B27 plus brain-derived neurotrophic factor (BDNF) for 7 d, E13-derived MSNs are 53.7% DARPP-32-positive and 29. 0% ARPP-21-positive; E17-derived MSNs are 66.8% DARPP-32-positive and 51.5% ARPP-21-positive. The percentage of calbindin-positive neurons also is increased under these conditions. Finally, ARPP-21 expression is reduced in mice with a targeted deletion of the BDNF gene. We conclude that BDNF is required for the maturation of a large subset of patch and matrix MSNs in vivo and in vitro. In addition, we introduce a culture system in which highly differentiated MSNs may be generated, maintained, and studied.
authors.affiliation: The Nathan Kline Institute for Psychiatric Research, Orangeburg, New York 10962, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ivkovic
authors.forename: M E
authors.initials: ME
authors.lastname: Ehrlich
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000494:pharmacology* / Q000502:physiology; D064026:Calbindins; D002421:Caudate Nucleus / Q000166:cytology*; D002452:Cell Count / Q000187:drug effects; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media; D004298:Dopamine / Q000494:pharmacology; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D005260:Female; D017353:Gene Deletion; D005786:Gene Expression Regulation / Q000187:drug effects*; D051379:Mice; D009414:Nerve Growth Factors / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D064026:Calbindins; D003470:Culture Media; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D064030:S100 Calcium Binding Protein G; C061368:cyclic AMP-regulated phosphoprotein ARPP-21; D005680:gamma-Aminobutyric Acid; D004298:Dopamine