Arrangement for internally controlling the selection of gear lines in a gearbox, which comprises: - a selection control member (10, 22) which is mounted so as to be rotatable in both directions between at least a first angular selection position and a second angular selection position, each of which is associated with a first selection line and a second selection line respectively; - a controlled actuator which can apply an actuating force to the control member (10, 22) in order to cause it to rotate in a first direction from its first angular selection position to its second angular selection position; and - a means for rotatably resiliently returning, in the opposite direction, the control member (10, 22) to its first angular selection position, the return means being independent of the control actuator; characterized in that the controlled actuator comprises an electric drive motor and a screw-nut assembly which comprises: - a drive screw which is rotated by the drive motor; and - a drive nut which is screwed onto the drive screw, is axially slidably guided and applies an actuating force to the control member (10, 22) in order to cause it to rotate in the first direction, in that the drive nut comprises an active portion which is designed as an axially oriented actuating rod, the free end of which cooperates with the control member (10, 22), in that the drive nut comprises a blind distal end which is extended by the active portion thereof designed as an actuating rod, and a proximal end into which a tapped bore opens in which the drive screw is screwed and in that the blind distal end of the drive nut comprises at least one through-hole which communicates with said tapped bore. - a selection control member (10, 22) which is mounted so as to be rotatable in both directions between at least a first angular selection position and a second angular selection position, each of which is associated with a first selection line and a second selection line respectively; - a controlled actuator which can apply an actuating force to the control member (10, 22) in order to cause it to rotate in a first direction from its first angular selection position to its second angular selection position; and - a means for rotatably resiliently returning, in the opposite direction, the control member (10, 22) to its first angular selection position, the return means being independent of the control actuator; characterized in that the controlled actuator comprises an electric drive motor and a screw-nut assembly which comprises: - a drive screw which is rotated by the drive motor; and - a drive nut which is screwed onto the drive screw, is axially slidably guided and applies an actuating force to the control member (10, 22) in order to cause it to rotate in the first direction, - a drive screw which is rotated by the drive motor; and - a drive nut which is screwed onto the drive screw, is axially slidably guided and applies an actuating force to the control member (10, 22) in order to cause it to rotate in the first direction, in that the drive nut comprises an active portion which is designed as an axially oriented actuating rod, the free end of which cooperates with the control member (10, 22), in that the drive nut comprises a blind distal end which is extended by the active portion thereof designed as an actuating rod, and a proximal end into which a tapped bore opens in which the drive screw is screwed and in that the blind distal end of the drive nut comprises at least one through-hole which communicates with said tapped bore.