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Neuroscience

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Three Primary Brain Vesicles: ANR Organizer and Fgf8

NEURO-7LMTAL

Signaling centers known as secondary organizers promote specification of the three domains in the anterior neural tube: prosencephalon or forebrain, mesencephalon or midbrain and rhombencephalon or hindbrain.

Anterior neural ridge (ANR) is one such center. It is located between the most rostral part of the neural plate and non-neural ectoderm. Molecules produced and released by ANR, primarily fibroblast growth factor 8 (Fgf8), promote specification and proliferation of anterior prosencephalic structures.

Which of the following is the CORRECT experimental manipulation and expected outcome pair?

A

Transplantation of ANR into more caudal region of neural plate will lead to development of an extra cerebellum.

B

Inhibition of Fgf8 signaling in the anterior neural tube will cause reduction in the size of telenecephalon.

C

Ablation of ANR will not affect development of optic vesicles.

D

Application of mitogens, chemicals that induce cell proliferation, can rescue defects in hypothalamus specification caused by deficient Fgf8 signaling from ANR.