Cooperative Effects of Sonic Hedgehog and NGF on Basal Forebrain Cholinergic Neurons

• Published in: Molecular and cellular neuroscience Vol. 19; no. 1; pp. 88 - 96
• Main Authors: Reilly, Jennifer Ott, Karavanova, Irina D., Williams, Kevin P., Mahanthappa, Nagesh K., Allendoerfer, Karen L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-01-2002
• Subjects: Acetylcholine - physiology; Age Factors; Alzheimer Disease - drug therapy; Animals; Cell Count; Cell Division - drug effects; Cells, Cultured; Choline O-Acetyltransferase - analysis; Drug Synergism; Gene Expression - physiology; Hedgehog Proteins; Membrane Proteins - analysis; Membrane Proteins - genetics; Mice; Mice, Transgenic; Nerve Growth Factor - pharmacology; Neurons - cytology; Neurons - drug effects; Neurons - enzymology; Patched Receptors; Patched-1 Receptor; Prosencephalon - cytology; Receptors, Cell Surface; RNA, Messenger - analysis; sonic hedgehog protein; Trans-Activators - genetics; Trans-Activators - pharmacology
• ISSN: 1044-7431; 1095-9327
• DOI: 10.1006/mcne.2001.1063

In ventromedial cells of the developing CNS, Sonic hedgehog (Shh) has been shown to affect precursor proliferation, phenotype determination, and survival. Here we show that Shh and its receptor, Ptc-1, are expressed in the adult rat basal forebrain, and that Ptc-1 is expressed specifically by cholinergic neurons. In basal forebrain cultures, Shh was added alone and in combination with nerve growth factor (NGF), and the number of cholinergic neurons was determined by choline acetyltransferase (ChAT) immunocytochemistry. By 8 days in vitro, Shh and NGF show a synergistic effect: the number of ChAT-positive cells after treatment with both factors is increased over untreated cultures or cultures treated with either factor alone. While Shh increases the overall basal level of proliferation, double-labeling of dividing neuronal precursors with [3H]thymidine followed by ChAT immunocytochemistry after they mature, demonstrates that the specific increase in cholinergic neurons is not due to this proliferation enhancement. These experiments imply a role for Shh in the development of postmitotic cholinergic neurons and suggest a therapeutic value for Shh in neurodegenerative disease.