—Using the method of integral-field ( 3D ) spectroscopy , we have investigated the kinematics and distribution of the gas and stars at the center of the early-type spiral galaxy with a medium scale bar NGC 7177 as well as the change in the mean age of the stellar population along the radius .
A classical picture of radial gas inflow to the galactic center along the shock fronts delineated by dust concentration at the leading edges of the bar has been revealed .
The gas inflow is observed down to a radius R = 1 ^ { \prime \prime } .5 –- 2 ^ { \prime \prime } , where the gas flows at the inner Lindblad resonance concentrate in an azimuthally highly inhomogeneous nuclear star formation ring .
The bar in NGC 7177 is shown to be thick in z coordinate ; basically , it has already turned into a pseudo-bulge as a result of secular dynamical evolution .
The mean stellar age inside the star formation ring , in the galactic nucleus , is old , \sim 10 Gyr .
Outside , at a distance R = 6 ^ { \prime \prime } -–8 ^ { \prime \prime } from the nucleus , the mean age of the stellar population is \sim 2 Gyr .
If we agree that the bar in NGC 7177 is old , then , obviously , the star formation ring has migrated radially inward in the last 1–-2 Gyr , in accordance with the predictions of some dynamical models .

Key words : galactic nuclei , galactic structure , galactic evolution .