ISOCAM 4 mu m imaging of the nuclear starburst in M83

We present ISOCAM images (1.5 arcsec resolution), in the Br alpha line and in the continuum at 4 mu m, of the starburst nuclear region in the nearby galaxy M83. The starburst is found to lie: a) along are joining the 2 mu m sources at S and SW of the nucleus to the NW 10 mu m peak, a possible indication of a propagating star formation; b) at the nucleus itself and at a bridge, linking the are to the nucleus, that could trace a gaseous bar. The strong 4 mu m continuum emission cannot be free-free and probably corresponds to the continuum emission associated with the Very-Small-Grain/PAH component of the dust.