Development of the Forebrain (IMAGE) Helmholtz Association Caption The dashed line marks the region of the neural tube out of which the forebrain develops. There in mouse embryos, a binding site (lipoprotein receptor LRP2) (green) for cholesterol is normally found (left image). This binding site plays a key role in the development of the forebrain. The signaling molecule sonic hedgehog (SHH) (red) arises from the structure marked with the arrow below the neural tube (prechordal plate) and accumulates in the overlying neural tube. Therefore a red signal is also visible in the forebrain structure. In mouse embryos in which the gene encoding LRP2 has been inactivated (right image), SHH is produced in the prechordal plate (arrow), but the signaling molecule does not accumulate in the overlying marked forebrain structure. The LRP2 receptor is lacking (no green signal). The researchers conclude that not only cholesterol is important for the activation and distribution of the signaling molecule SHH, but that also a lipoprotein receptor LRP2 is required in the target field to enhance the signal molecule. Credit Photo: Annabel Christ/ Copyright: MDC Usage Restrictions Credit required License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.