A compound of formula, wherein X 1, X 2 and X 3 are, independently of each other, N or CH; with the proviso that at least two of X 1, X 2 and X 3 are N; Y is N or CH; R 1 and R 2 are independently of each other (i) a morpholinyl of formula wherein the arrow denotes the bond in formula; and wherein R 3 and R 4 are independently of each other H, C 1 -C 3 alkyl optionally substituted with one or two OH, C 1 -C 2 fluoroalkyl, C 1 -C 2 alkoxy, C 1 -C 2 alkoxyC 1 -C 3 alkyl, CN, or C O-C 1 -C 2 alkyl; or R 3 and R 4 form together a bivalent residue -R 5 R 6 - selected from C 1 -C 3 alkylene optionally substituted with 1 to 4 F, -CH 2 -O-CH 2 -, -CH 2 -NH-CH 2 -, or any of the structures wherein the arrows denote the bonds in formula; or (ii) a saturated 6-membered heterocyclic ring Z selected from thiomorpholinyl and piperazinyl, optionally substituted by 1 to 3 R 7; wherein R 7 is independently at each occurrence C 1 -C 3 alkyl optionally substituted with one or two OH, C 1 -C 2 fluoroalkyl, C 1 -C 2 alkoxyC 1 -C 3 alkyl, C 3 -C 6 cycloalkyl; or two R 7 substituents form together a bivalent residue -R 8 R 9 -selected from C 1 -C 3 alkylene optionally substituted with 1 to 4 F, -CH 2 -O-CH 2 - or -O-CH 2 CH 2 -O-; with the proviso that at least one of R 1 and R 2 is a morpholinyl of formula II; and tautomers, solvates and pharmaceutically acceptable salts thereof, for use in the prevention or treatment of a neurological disorder in a subject. X 1, X 2 and X 3 are, independently of each other, N or CH; with the proviso that at least two of X 1, X 2 and X 3 are N; Y is N or CH; R 1 and R 2 are independently of each other (i) a morpholinyl of formula wherein the arrow denotes the bond in formula; and wherein R 3 and R 4 are independently of each other H, C 1 -C 3 alkyl optionally substituted with one or two OH, C 1 -C 2 fluoroalkyl, C 1 -C 2 alkoxy, C 1 -C 2 alkoxyC 1 -C 3 alkyl, CN, or C O-C 1 -C 2 alkyl; or R 3 and R 4 form together a bivalent residue -R 5 R 6 - selected from C 1 -C 3 alkylene optionally substituted with 1 to 4 F, -CH 2 -O-CH 2 -, -CH 2 -NH-CH 2 -, or any of the structures wherein the arrows denote the bonds in formula; or (ii) a saturated 6-membered heterocyclic ring Z selected from thiomorpholinyl and piperazinyl, optionally substituted by 1 to 3 R 7; wherein R 7 is independently at each occurrence C 1 -C 3 alkyl optionally substituted with one or two OH, C 1 -C 2 fluoroalkyl, C 1 -C 2 alkoxyC 1 -C 3 alkyl, C 3 -C 6 cycloalkyl; or two R 7 substituents form together a bivalent residue -R 8 R 9 -selected from C 1 -C 3 alkylene optionally substituted with 1 to 4 F, -CH 2 -O-CH 2 - or -O-CH 2 CH 2 -O-; (i) a morpholinyl of formula wherein the arrow denotes the bond in formula; and wherein R 3 and R 4 are independently of each other H, C 1 -C 3 alkyl optionally substituted with one or two OH, C 1 -C 2 fluoroalkyl, C 1 -C 2 alkoxy, C 1 -C 2 alkoxyC 1 -C 3 alkyl, CN, or C O-C 1 -C 2 alkyl; or R 3 and R 4 form together a bivalent residue -R 5 R 6 - selected from C 1 -C 3 alkylene optionally substituted with 1 to 4 F, -CH 2 -O-CH 2 -, -CH 2 -NH-CH 2 -, or any of the structures wherein the arrows denote the bonds in formula; or wherein the arrow denotes the bond in formula; and wherein R 3 and R 4 are independently of each other H, C 1 -C 3 alkyl optionally substituted with one or two OH, C 1 -C 2 fluoroalkyl, C 1 -C 2 alkoxy, C 1 -C 2 alkoxyC 1 -C 3 alkyl, CN, or C O-C 1 -C 2 alkyl; or R 3 and R 4 form together a bivalent residue -R 5 R 6 - selected from C 1 -C 3 alkylene optionally substituted with 1 to 4 F, -CH 2 -O-CH 2 -, -CH 2 -NH-CH 2 -, or any of the structures wherein the arrows denote the bonds in formula; or (ii) a saturated 6-membered heterocyclic ring Z selected from thiomorpholinyl and piperazinyl, optionally substituted by 1 to 3 R 7; wherein R 7 is independently at each occurrence C 1 -C 3 alkyl optionally substituted with one or two OH, C 1 -C 2 fluoroalkyl, C 1 -C 2 alkoxyC 1 -C 3 alkyl, C 3 -C 6 cycloalkyl; or two R 7 substituents form together a bivalent residue -R 8 R 9 -selected from C 1 -C 3 alkylene optionally substituted with 1 to 4 F, -CH 2 -O-CH 2 - or -O-CH 2 CH 2 -O-;