a | Normal distribution | One-way ANOVA Bonferroni *post hoc* | *p* = 0.0043 | Mean number of branch points |

b | Normal distribution | One-way ANOVA Bonferroni *post hoc* | *p* = 0.0003 | Mean number of total varicosities |

c | Normal distribution | One-way ANOVA Bonferroni *post hoc* | *p* = 0.0001 | Mean number of off-target varicosities |

d | Normal distribution | One-way ANOVA Bonferroni *post hoc* | *p* = 0.0001 | Mean number of AIS varicosities |

e | Normal distribution | Student’s *t* test, two tailed, unpaired | *p* = 0.542 | Mean number of varicosities/AIS |

f | Normal distribution | Student’s *t* test, two tailed, unpaired | *p* = 0.244 | Mean number of cartridges |

g | Normal distribution | One-way ANOVA Bonferroni *post hoc* | *p* < 0.0001 | Mean % of off-target varicosities |

h | Normal distribution | Student’s *t* test, two tailed, unpaired | *p* < 0.0001 | Mean % of VGAT+ varicosities P16 |

i | Normal distribution | Student’s *t* test, two tailed, unpaired | *p* = 0.0191 | Mean number of branch points (transpl.) |

j | Normal distribution | Student’s *t* test, two tailed, unpaired | *p* = 0.0238 | Mean number of total varicosities (transpl.) |

k | Normal distribution | Student’s *t* test, two tailed, unpaired | *p* < 0.0001 | Mean % of off-target varicosities (transpl.) |

l | Normal distribution | Student’s *t* test, two tailed, unpaired | *p* < 0.0001 | Mean % of Syp+ varicosities |

m | Normal distribution | One-way ANOVA Bonferroni *post hoc* | *p* = 0.0002 | Mean density of vesicles P16 |

n | Normal distribution | One-way ANOVA Bonferroni *post hoc* | *p* < 0.0001 | Mean roundness of vesicles P16 |

o | Normal distribution | Student’s *t* test, two tailed, unpaired | *p* < 0.0001 | Mean % of VGAT+ varicosities P28 |

p | Normal distribution | Student’s *t* test, two tailed, unpaired | *p* = 0.78 | Mean density of vesicles P28 |

q | Normal distribution | Student’s *t* test, two tailed, unpaired | *p* < 0.0001 | Mean roundness of vesicles P28 |