 Fluorescent beads on dirty slide used to set the laser beam of the two-photon microscope. Unproper settings leads to non optimal imaging. |  Dry ice sublimation producing carbon dioxide clouds. Dry ice is used to freeze mice brain before cutting them. |  Dried PBS salt in a petri dish. PBS is used as solution for various immunostaining and mounting. |  Stacked eppendorf tubes. |  Neighbor pixels correlation of a confocal image from a dual color immunostained brain. |
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 Cresyl violet used to stain cell membrane getting mixed into PBS. The wrong concentration leads to a bad staining. |  Retrograde labelling of the dorsal raphe after CTB injection in the paraventricular thalamus. Unexpected brain structure labelled. |  |  Statistical comparison of cell number expressing a reporter in two different samples. R programming error. |  Grating used to condensate the two-photon laser beam at a correct diameter and allow its proper alignement. Incorrect laser settings lead to unprecise imaging. |
 Behavior box used to test the effect of light stimulation on foraging behavior in mice expressing channelrhodopsin in the bed nucleus of the stria terminalis. No significant increase of foraging behavior. |  Fluorescent western blot used for genotyping. |  Snow and ice resulting from humidity leaking inside the -80°C freezer. 23.07.2015. Dysfunctioning freezer leads to damaged and unusable samples. |  Testing sample of a root used for setting up parameters of confocal microscope lasers. Suboptimal settings lead to imaging errors due to overlapping fluorescent signal. |  Color coded matrix of random numbers. 03.04.2015. Matlab programming error while bootstrapping shuffled neuronal activity. |
 Mouse brain in a falcon tube. The brain is unusable for histology if the fixation with paraformaldehyde fails. |  Granule cell layer in the olfactory bulb expressing channelrhodopsin. 04.11.2014. Slice not usable because of air bubbles. |  Archeorhodopsin infection of prefrontal neurons . Because the wells containing the brain slices have been forgotten outside the fridge, moisture grew up and damaged the normal structure of the brain. The verification of the infection was impossible. |  Green laser used to photo-inhibit neurons in the prefrontal cortex during a sensory discrimination task. The inhibition did not affect the perceptual decision. |  Infrared recording frame of a mouse pupil size. Measuring the pupil size is a readout of the animal reflex and sensation. |
 Detection and color-coded labelling of imaged neurons. Because of motion artifacts during the imaging acquisition, the analysis led to errors since individual neurons were sometimes parsed and clustered into two distinct ones. |  Archeorhodopsin expression in neurons of the paraventricular thalamus. The opto-inhibition of those neurons during the learning of a fearful pavlovian conditioning did not reduce the expression of fear as hypothesized. |  Automatized quantification of claustral axons density in the cortex by pixel intensity thresholding and surface segmentation. 15.05.2017. Non optimal Matlab routine leading to aberrant segments. |