A nerve regeneration which comprises a compound is represented by formula
(I): (wherein all symbols are shown in the description), a salt thereof
or a prodrug thereof. The compound of the present invention is suppresses
nerve cell death as a substance for accelerating growth and/or
differentiation of stem cells (nerve stem cells, embryonic stem cells,
bone marrow cells, etc.), a substance for accelerating growth and/or
differentiation of nerve precursor cells, a potentiator for neurotrophic
factor activity, a neurotrophic factor-like substance or a
neurodegenerative suppressor, and accelerates repair and regeneration of
nerve tissues by neogenesis, regeneration and/or axon evolution. In
addition, the compound of the present invention is useful for preparation
from brain tissues, bone marrow and/or embryonic stem cells of cells for
transplant (nerve stem cells, nerve precursor cells, nerve cells, etc.)
and also accelerates grafting, growth, differentiation and/or function
expression of cells for transplant whereupon it is useful for prevention
and/or treatment of neurodegenerative diseases.