PS-on GABAergic Oxysophocarpine neurons indicating that GABA in addition to glycine play an important role in sensory and motor inhibition during PS. In the present study the changes in c-Fos expression areinterpreted as reflecting changes in neuronal activity associated with the different experimental conditions. It must be mentioned, nonetheless, that such changes may also reflect changes in other cellular processes that can be stimulated by chemical messengers independent of neuronal discharge, although also dependent on changes in intracellular calcium. In spite of these limitations, c-Fos immunostaining is considered to be a useful tool to map activated neurons. Here we show that the distribution and number of Fos+ labeled neurons were similar with our previous publications using the same deprivation recovery method validating our protocol combining ISH of GAD67 and Fos staining. Our results 
are however largely different with those obtained in the three previous studies reporting the distribution of GAD and Fos-immunoreactive neurons using nearly the same protocol than us excepting a shorter 48 h PS deprivation. We indeed also observed significantly more Benzoylaconine Fos-GAD double-labeled cells in the VTA, LDTg, PPTg, CGPn, PnC, RMg, Gi and the GiA after PS recovery compared to control and PSD condition and in the total number of Fos + neurons in the PnO. However, for the latter structure as well as the substantia nigra, median raphe and SLD, we did not observe a change in the number of Fos-GAD neurons in PSR animals compared to the PSD and PSC ones. These discrepancies are likely due to the fact that the Fos antibody used in Maloney et al. studies labeled a large number of cells in basal condition in contrast to the one used in our and the other previous Fos studies likely precluding them to extract the Fos staining specifically induced by the protocol. Further, the development and use in our study of the highly sensitive ISH instead of immunohistochemistry to label GAD-containing neurons likely contributed to a more complete identification of GABAergic neurons. Gastrulation is a critical process during early vertebrate development involving changes in cell fate and cell behavior to generate the three germ layers of the embryo. Wnts are evolutionarily conserved extracellular glycoproteins required for regulation of these cell fates and behaviors.