Isolation of Rat Telencephalic Neural Explants to Assay Shh GABAergic Interneuron Differentiation-Inducing Activity

  • Rina Mady
  • Jhumku D. Kohtz
Part of the Methods Inmolecular Biology™ book series (MIMB, volume 397)


Multiple assays for Shh activity using cell lines, primary cultures, and explanted tissue have been described. We first described the use of E11.5 rat dorsal telencephalic explants to assay Shh ventralizing and differentiation-inducing activity in Kohtz et al. (1). Using this assay, we subsequently showed that N-lipid modification is critical for Shh activity in the telencephalon (2). In vivo assays for lipid-modified Shh support the results of our E11.5 telencephalic neural explant assay (2). More recently, the method of isolating telencephalic explants was improved by an intraocular grid, increasing both its accuracy and reproducibility (3). Shh induces the expression of the following ventral telencephalic markers: MASH-1, the Dlx’s, and Islet 1/2. Therefore, this assay for Shh induction of GABAergic interneurons defines a competent, but naïve region within the E11.5 dorsal telencephalon, allowing the study of GABAergic interneuron induction and differentiation from an unspecified progenitor population.

Key Words

Sonic hedgehog forebrain telencephalon GABAergic neural explants Dlx differentiation 


  1. 1.
    Kohtz, J. D., Baker, D. P., Corte, G., and Fishell, G. (1998) Regionalization within the mammalian telencephalon is mediated by changes in responsiveness to Sonic Hedgehog. Development 125, 5079–5089.PubMedGoogle Scholar
  2. 2.
    Kohtz, J. D., Lee, H. Y., Gaiano, N., et al. (2001) N-terminal fatty-acylation of Sonic Hedgehog enhances the induction of rodent ventral forebrain neurons. Development 128, 2351–2363.PubMedGoogle Scholar
  3. 3.
    Feng, J., White, B., Tyurina, O. V., et al. (2004) Synergistic and antagonistic roles of the Sonic Hedgehog N-and C-terminal lipids. Development 131, 4357–4370.CrossRefPubMedGoogle Scholar

Copyright information

© Humana Press Inc., Totowa, NJ 2007

Authors and Affiliations

  • Rina Mady
    • 1
  • Jhumku D. Kohtz
    • 1
  1. 1.Program in Neurobiology and Department of Pediatrics, Children’s Memorial Hospital and Feinberg School of MedicineNorthwestern University, N. HalstedChicagoUSA

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