As a preliminary result of the Herschel Gould Belt survey (André et al. 2010) in the Orion B cloud complex we find a clear connection between the locations of the detected prestellar cores and the column density values. We find that the vast majority of the gravitationally bound prestellar cores are detected above a high column density of about 6-7 × 1021 cm-2 (A V ˜ 6-7). This is in very good agreement with dense core formation thresholds found in other regions. For Orion B, a similar limit appears both in the distribution of background column density values of the prestellar cores, and in the column density PDF of the region. Within our core formation scenario, the found threshold can be translated as the column density above which the filaments become gravitationally unstable and fragment into cores.