We have a new paper in Nature Protocols on the validation of a high-resolution optical imaging technique.
Figure 8 – Quantification of L6 terminaux bouton density and turnover (a) Examples of appearing (arrowheads) and disappearing (arrows) terminaux boutons in the somatosensory cortex, imaged through a chronic cranial window on the day of the surgery, and 14 and 21 d later. (b) Bouton density under the cranial window remains constant over time and is comparable with bouton densities in naive fixed brains (fixed control). (c) Survival fractions of boutons imaged immediately after the surgery are similar to those imaged after a recovery period of 10–14 d. Open markers represent survival fractions in experiments, where imaging was started immediately after the surgery (same mice as in b), solid markers represent experiments that included a waiting period of 2 weeks after the surgery (results from an earlier study16). (d) Turnover ratio (TOR) over 4-day imaging intervals. Imaging was started 10 d after the surgery (data from different studies). TORs are, on average, constant over long periods of imaging (> 45 d). Data by V.D.P. All experiments using animals were carried out under institutional and national guidelines.