  We analyze the kinematics of the central regions of five isolated Seyfert
spiral galaxies from the DEGAS sample (four with new data presented in this
paper, IC184, UGC3223, NGC2639, NGC6814, and NGC6951 from our previous data),
by using long slit spectroscopy in the CaII triplet range (at ~ 8600 A)
obtained with a 4m-class telescope. A drop of the velocity dispersions in the
innermost 1-3 arcsec is observed in four of them, and hinted in the remaining
galaxy (NGC6814). The available HST images for our sample together with another
nine galaxies with reported velocity dispersion drops, are also used to
investigate the presence of morphological inner structures at the scales of the
kinematical drops. Evidence for disk-like shapes is found in 12 out of the 14
cases. The only exceptions are NGC6814 and NGC6951. Existing N-body simulations
including stars, gas and star formation predict that such a drop is most
probably due to a young stellar population born from dynamically cold gas
accreted in a circumnuclear disk formed during an episode of central gas
accretion driven by a bar. The equivalent widths of the Calcium triplet lines
for our 5 galaxies have been measured. Even if the profiles could be formally
consistent with constant EW(CaT) values, they seem to indicate the presence of
a local maximum in the regions corresponding spatially to the drops; if
confirmed, this would imply the presence of a different stellar population,
whose properties could help constraining the models.
