Abstract: The present invention provides compounds represented by formula (I), pharmaceutically acceptable salts thereof, N-oxides thereof, solvates thereof or prodrugs thereof (wherein the characters are as defined in the description). The compounds represented by formula (I) have affinity and selectivity for the gamma-aminobutyric acid A receptor subunit alpha 5 (GABAA ?5) and act as GABAA ?5 negative allosteric modulators (GABAA ?5 NAM), so that they are useful in the prevention and/or treatment of diseases which are related to the GABAA ?5 such as Alzheimer's disease.

Abstract: The present invention provides compounds represented by formula (I), pharmaceutically acceptable salts thereof, N-oxides thereof, solvates thereof or prodrugs thereof (wherein the characters are as defined in the description). The compounds represented by formula (I) have affinity and selectivity for the gamma-aminobutyric acid A receptor subunit alpha 5 (GABAA ?5) and act as GABAA ?5 negative allosteric modulators (GABAA ?5 NAM), so that they are useful in the prevention and/or treatment of diseases which are related to the GABAA ?5 such as Alzheimer's disease.

Abstract: The present invention provides compounds represented by formula (I), pharmaceutically acceptable salts thereof, N-oxides thereof, solvates thereof or prodrugs thereof (wherein the characters are as defined in the description). The compounds represented by formula (I) have affinity and selectivity for the gamma-aminobutyric acid A receptor subunit alpha 5 (GABAA ?5) and act as GABAA ?5 negative allosteric modulators (GABAA ?5 NAM), so that they are useful in the prevention and/or treatment of diseases which are related to the GABAA ?5 such as Alzheimer's disease.

Abstract: 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.

Abstract: 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.