æz ˈæksɑːnz nˌɑːt dˈɛstɪnd tə kɹˈɔs ðə mˈɪdlaɪn pɹˈɑːdʒɛkt θɹuː ðə nˈʊɹɹəl tˈuːb ðeɪ ɑːɹ ɹᵻpˈɛld baɪ ðə lˈɪɡænd slˈɪt wˌɪtʃ ɪz ɛkspɹˈɛst ɪnðə sˈɛlz ʌvðə flˈoːɹ plˈeɪt.
As axons not destined to cross the midline project through the neural tube they are repelled by the ligand slit which is expressed in the cells of the floor plate.