In vivo autofluorescence lifetime imaging of spatial metabolic heterogeneities and learning-induced changes in the Drosophila mushroom body

  1. Philémon Roussel
  2. Mingyi Zhou
  3. Chiara Stringari
  4. Thomas Preat
  5. Pierre-Yves Plaçais  Is a corresponding author
  6. Auguste Genovesio  Is a corresponding author
  1. Computational Bioimaging and Bioinformatics, IBENS, École normale supérieure, CNRS, INSERM, Université PSL, France
  2. Energy & Memory, Brain Plasticity Unit, ESPCI, CNRS, Université PSL, France
  3. Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, France
17 figures, 10 tables and 1 additional file

Figures

Figure 1 with 7 supplements
In vivo measurements of NAD(P)H state over the central brain and across mushroom body (MB) regions.

Scale bars: 50 µm. Axes indicate anterior (A), dorsal (D), and right (R) anatomical orientations. The circled dot and cross indicate the directions pointing toward and away from the viewer, respectively. (a) Illustration of the main steps of the mapping of NAD(P)H decay parameters over the central brain. Fluorescence lifetime imaging (FLIM) images were spatially binned using a disk-shaped kernel (see Methods) and the resulting curves were fitted to extract decay parameters. The parameter histograms are derived from the whole 3D image. Each step is illustrated by a single horizontal section of the example 3D image. (b) Heatmaps of ffree, τbound, and τmean over three horizontal slices of a single image. Contours of the MB, extracted from the MB-DsRed image, are superimposed in white. Voxels with photon counts under 500 are shown in gray. The cortex and neuropil are marked on the first slice of the τbound heatmap with red letters ‘c’ and ‘n,’ respectively. (c) Average of all transverse sections of the MB-DsRed image corresponding to panel b (gray), with colored segmentation regions superimposed on the left MB. White dashed lines denote the depth of the horizontal sections shown in panel b. (d) Horizontal view of a left MB showing the maximum intensity projection of the Kenyon cell (KC)-specific marker with superimposed segmentation regions. The circled dot indicates the direction pointing towards the viewer. (e) Within-subject averages of ffree and τbound in the segmented MB regions, for five flies. Gray horizontal lines indicate the cross-subject mean values. No significant variations of ffree were observed between the considered regions (repeated measures ANOVA, F3,12 = 1.7, p=0.21). Significant variations of τbound were observed between areas (repeated measures ANOVA, F3,12 = 14.8, p=2.4×10–4). Three post-hoc comparisons were performed to compare the somata and calyx region with the other areas. It showed that τbound was significantly higher in the somata and calyx (n=5, µ=3.67±0.23 ns) compared to the peduncle (n=5, µ=3.21±0.07 ns; paired samples Student’s t-test, t4=4.7, Bonferroni-adjusted p=2.7×10–2), the vertical lobe (n=5, µ=3.32±0.10 ns; paired samples Student’s t-test, t4=4.0, Bonferroni-adjusted p=4.8×10–2) and the medial lobes (n=5, µ=3.18±0.09 ns; paired samples Student’s t-test, t4=4.3, Bonferroni-adjusted p=3.8×10–2).

Figure 1—figure supplement 1
Examples of fit and distribution of 2I* for Dataset 1.

For each subject’s image, all voxels within the segmented mushroom body (MB) regions were included. On the left, the distributions of the 2I* quality parameter are displayed, with the dashed line marking the empirically defined threshold for poor fits (2I*=200). On the right, three post-binning decay curves randomly selected from each image are shown, along with their corresponding bi-exponential model fits. Below each decay plot, the residuals (differences between the observed and fitted decays) are displayed.

Figure 1—figure supplement 2
Distributions of ffree and τbound in different segmented mushroom body (MB) regions for the subjects of Dataset 1.

The dotted line indicates the mean value of each distribution. (a) ffree distributions. (b) τbound distributions.

Figure 1—video 1
Spatial distributions of NAD(P)H properties over the volume of the central brain of subject 1.

Heatmaps of ffree, τbound, and τmean over horizontal slices are displayed sequentially. Contours of the mushroom body (MB), extracted from the MB-DsRed image, are superimposed in white. Voxels with photon counts under 500 are shown in gray.

Figure 1—video 2
Spatial distributions of NAD(P)H properties over the volume of the central brain of subject 2.

Heatmaps of ffree, τbound, and τmean over horizontal slices are displayed sequentially. Contours of the mushroom body (MB), extracted from the MB-DsRed image, are superimposed in white. Voxels with photon counts under 500 are shown in gray.

Figure 1—video 3
Spatial distributions of NAD(P)H properties over the volume of the central brain of subject 3.

Heatmaps of ffree, τbound, and τmean over horizontal slices are displayed sequentially. Contours of the mushroom body (MB), extracted from the MB-DsRed image, are superimposed in white. Voxels with photon counts under 500 are shown in gray.

Figure 1—video 4
Spatial distributions of NAD(P)H properties over the volume of the central brain of subject 4.

Heatmaps of ffree, τbound, and τmean over horizontal slices are displayed sequentially. Contours of the mushroom body (MB), extracted from the MB-DsRed image, are superimposed in white. Voxels with photon counts under 500 are shown in gray.

Figure 1—video 5
Spatial distributions of NAD(P)H properties over the volume of the central brain of subject 5.

Heatmaps of ffree, τbound, and τmean over horizontal slices are displayed sequentially. Contours of the mushroom body (MB), extracted from the MB-DsRed image, are superimposed in white. Voxels with photon counts under 500 are shown in gray.

Figure 2 with 1 supplement
Establishment of a reproducible mushroom body (MB) template.

(a) Illustration of the main steps of the preprocessing pipeline. This process was applied to the 165 MB images obtained from flies expressing fluorophore DsRed in the cytoplasm of all Kenyon cells (KCs) (Dataset 3). (b) Illustration of the template building process. An initial template is obtained by averaging all preprocessed images. The images are then registered to this intermediate template. The resulting registered images and transformations are averaged. A transformation proportional to the inverse of the mean transformation is applied to the average registered image to get an updated template image. The cycle was repeated several times to obtain the final template. (c) Examples of preprocessed MB images and final template. The left and right columns show dorsal and lateral maximum intensity projections of each image. (d) Views of the MB template image generated through volume rendering with ParaView software (Ahrens et al., 2005). Axes indicate anterior (A), dorsal (D), ventral (V), and right (R) anatomical orientations. View-aligned axes orientations depicted with dot (towards viewer) and cross (away from viewer). Scale bar: 25 µm.

Figure 2—figure supplement 1
Establishment of masks for the somata and calyx regions.

Illustration of the processes used to obtain masks isolating the somata and calyx regions. Each step is illustrated by a slice of 3D image at a fixed depth. Both masks are defined over the previously generated template image of the cortical region of the MB. The somata mask was established using the images of Dataset 4. After registering the images to the template, based on the cytosolic marker channel, the nuclear marker channel was averaged and thresholded. The calyx mask was obtained by thresholding the template image and excluding the voxels belonging to the somata region. Scale bar: 25 μm.

Figure 3 with 1 supplement
NAD(P)H states in the somata and calyx regions of the mushroom body (MB), for naive and conditioned flies.

Scale bars: 25 µm. (a) Illustration of the main steps of the computation of the metabolic profile in the Kenyon cell (KC) somata region. The fluorescence intensity of the KC-specific cytosolic marker MB-DsRed was simultaneously recorded with the NAD(P)H fluorescence lifetime imaging (FLIM) image. The marker image was segmented using thresholding to isolate the MB. Next, we used a MB template with previously defined masks delineating the KC somata region (purple) and the calyx (turquoise). This template was registered to the segmented marker image. The registered masks could be used to isolate the target area (the somata region in this illustration) in the FLIM image. The masked FLIM image was spatially binned using a disk-shaped kernel (see Methods), and the resulting decays were fitted to obtain ffree and τbound values in the target area. Each step is illustrated by a single horizontal section of the example 3D image. (b) Left: Horizontal sections of the average spatial distribution of ffree in the somata area and calyx in naive flies. The average distribution was obtained by computing maps of ffree in the posterior MB region, registering them to the MB template based on the corresponding MB-DsRed images and averaging the results. Axes indicate anterior (A), dorsal (D) and right (R) anatomical orientations. Top right: Average of ffree across all transverse sections of the average spatial distribution, with white dashed lines indicating the depth of the horizontal sections. The circled cross indicates the direction pointing away from the viewer. Bottom right: Within-subject averages of ffree in the somata and calyx regions. ffree values in the somata region (n=17, µ=0.682±0.021) were significantly lower than in the calyx (n=17, µ=0.746±0.023; paired samples Student’s t-test, t16=16.3, p=2.1×10–11). (c) Top: Schematic representation of the aversive conditioning protocol. Control flies underwent unpaired training, receiving electric shocks, followed by sequential exposure to odors A and B after a 2 min break. Conditioned flies underwent paired conditioning, receiving electric shocks while exposed to odor A, followed by exposure to odor B. Bottom: Within-subject averages of ffree in the somata and calyx regions for conditioned flies. In the somata region, ffree values for the flies subjected to unpaired stimuli (n=15, µ=0.662±0.016) were not significantly different than for the ones subjected to paired conditioning (n=16, µ=0.658±0.013; Student’s t-test, t29=0.8, p=0.43). In the calyx, ffree values for the flies subjected to unpaired stimuli (n=15, µ=0.709±0.020) were not significantly different than for the ones subjected to paired conditioning (n=16, µ=0.706±0.017; Student’s t-test, t29=0.4, p=0.67).

Figure 3—figure supplement 1
Influence of memory conditioning on average τbound values in the somata and calyx region.

(a) Left: Horizontal sections of the average spatial distribution of τbound in the somata area and calyx in naive flies. The average distribution was obtained by computing maps of τbound in the posterior MB region, registering them to the mushroom body (MB) template based on the corresponding MB-Dsred images and averaging the results. Axes indicate anterior (A), dorsal (D), and right (R) anatomical orientations. Right: Average of ffree across all transverse sections of the average spatial distribution, with white dashed lines indicating the depth of the horizontal sections. The circled cross indicates the direction pointing away from the viewer. Scale bars: 25 μm. (b) Within-subject averages of τbound in the somata region and in the area encompassing the somata and calyx. τbound values were significantly higher in the Kenyon cell (KC) somata region (n=17, µ=3.94±0.19) than in the calyx (n=17, µ=3.31±0.09 ns; dependent-samples Student’s t-test, t16=17.6, p=6.9×10–12). (c) Within-subject averages of τbound in the somata and calyx regions, for flies subjected to unpaired and paired stimuli. In the somata region, τbound values for the flies subjected to unpaired stimuli (n=15, µ=4.01±0.16 ns) were not significantly different than for the ones subjected to paired conditioning (n=16, µ=3.95±0.26 ns; Student’s t-test, t29=0.84, p=0.41). In the calyx region, τbound values for the flies subjected to unpaired stimuli (n=15, µ=3.24±0.20 ns) were not significantly different than for the ones subjected to paired conditioning (n=16, µ=3.24±0.11 ns; Student’s t-test, t29=0.02, p=0.99).

Figure 4 with 2 supplements
NAD(P)H states around somata of Kenyon cell (KC) subtypes in naive and conditioned flies.

(a) Illustration of the main steps of the computation of the metabolic profile around the somata of a given KC subtype. Standard fluorescence intensity image of the subtype-specific nuclear marker was simultaneously recorded with the NAD(P)H fluorescence lifetime imaging (FLIM). The marker image was thresholded to remove background noise, and the resulting segmentation was used to mask the FLIM image. The masked FLIM image was spatially binned using a disk-shaped kernel (see Methods) and fitted to obtain ffree values in the target area. Each step is illustrated by a single horizontal section of the example 3D image. Scale bar: 25 µm. (b) Within-subject averages of ffree near the somata of α/β, α'/β', and γ KCs show significant variations (one-way ANOVA, F2,40 = 7.1, p=2.3×10–3). ffree is significantly higher near α/β neurons (n=13, µ=0.730±0.019) than near γ neurons (n=15, µ=0.701±0.022; Student’s t-test, t26=3.6, Bonferroni-adjusted P=3.6×10–3). The values of ffree for α'/β' neurons (n=15, µ=0.715±0.018) were not significantly different from those near α/β (Student’s t-test, t26=2.0, Bonferroni-adjusted p=0.16) or γ neurons (Student’s t-test, t28=1.9, Bonferroni-adjusted p=0.21). (c) Within-subject averages of ffree near the somata of α/β and γ KCs after odor conditioning. Near α/β somata, ffree is significantly lower after paired conditioning (n=19, µ=0.718±0.020) compared to the control condition (n=18, µ=0.735±0.025; Student’s t-test, t35=2.0, p=4.99×10–2). No statistically significant difference was observed near γ somata between conditioned (n=12, µ=0.700±0.017) and control flies (n=11, µ=0.693±0.011; Student’s t-test, t21=1.1, p=0.30).

Figure 4—figure supplement 1
Measures of τbound near the somata of Kenyon cell (KC) subtypes in naive and conditioned flies.

(a) Within-subject averages of τbound near the somata of α/β, α'/β', and γ KCs. No significant variation is observed (one-way ANOVA, F2,40=1.5, p=0.23) between α/β (n=13, µ=3.85±0.22 ns), α'/β' (n=13, µ=3.83±0.22 ns), and γ KCs (n=13, µ=3.97±0.26 ns). (b) Within-subject averages of τbound near the somata of α/β and γ KCs after odor conditioning. Near α/β somata, τbound is higher after paired conditioning (n=19, µ=3.82±0.18 ns) than in the control condition (n=18, µ=3.70±0.22 ns) but this difference is not statistically significant (Student’s t-test, t35=1.9, p=6.1×10–2). No statistically significant difference was observed either near γ somata between conditioned (n=12, 3.92±0.28 ns) and control flies (n=11, 3.92±0.24 ns; Student’s t-test, t21=0.0, p=0.97).

Figure 4—figure supplement 2
Influence of Ldh knockdown on ffree and τbound around the somata of γ neurons.

These plots compare flies with an Ldh knockdown mutation (Ldh-KD) with control flies. Left: Within-subject averages of ffree near the somata of γ Kenyon cell (KCs). No significant difference was observed between controls (n=12, µ=0.695±0.011) and mutated flies (n=12, µ=0.684±0.039; t22=1.1, p=0.27). Right: Within-subject averages of τbound near the somata of γ KCs. No significant difference was observed between controls (n=12, µ=4.00±0.16 ns) and mutated flies (n=12, µ=3.95±0.31 ns; t22=0.52, p=0.61).

Influence of memory conditioning on average ffree and τbound values around α/β Kenyon cells (KCs) in ALAT-KD flies.

Average decay parameter values near α/β somata in ALAT-KD mutant flies following unpaired versus paired memory conditioning. Left: Within-subject averages of ffree. No significant difference was observed between unpaired (n=18, µ=0.684±0.025) and paired conditions (n=17, µ=0.690±0.027; t33=0.71, p=0.48). Right: Within-subject averages of τbound. No significant difference was observed between unpaired (n=18, µ=3.90±0.19 ns) and paired conditions (n=17, µ=3.90±0.15 ns; t33=0.05, p=0.96).

Appendix 1—figure 1
Validation of the mushroom body (MB) template.

(a) Schematic illustrating the process of evaluation of the amount of displacement required to match MB images to different target images, namely the template, the raw average, or a randomly selected image. (b) Mean displacements resulting from the registration of all images of the dataset to different target images. Registration to a single image was performed 5 times on different randomly chosen images.

Appendix 1—figure 2
Evaluation of intra-subject and intra-hemisphere similarities in the spatial distribution of mushroom body (MB) neuronal subtypes.

(a) Schematic illustrating the method used to assess differences between templates generated from single or mixed hemispheres. This process used images preprocessed for template building (Figure 2a), downsampled by a factor of 2 (using linear interpolation and anti-aliasing filtering) to reduce the computational cost. Step 1: The complete set of preprocessed images is randomly divided into two non-overlapping half sets, arranged in random order. In the mixed hemispheres case, the half sets are created by including both left and right images indiscriminately. In the inter-hemispheres case, the first and second halves exclusively contain left and right MB images, respectively. Step 2: A template is constructed using the first N images from each half set, where N represents the subset size. Step 3: The two resulting templates are compared by registering one to the other using rigid registration and computing the normalized image distance between the aligned templates. This procedure was repeated with eight different random splits performed for each case. (b) Comparison of the normalized image distances between templates constructed from subsets of varying sizes, consisting of either mixed or separate hemispheres. In the 30-image case, the mixed-hemisphere distances (n=8, µ=11.7±2.0%) were significantly lower than inter-hemisphere distances (n=8, µ=14.4±1.6%; Student’s t-test, t14=2.8, p=1.4×10–2). (c) Overlapped maximum intensity projections of two templates obtained using all available left MB images (in red) and right MB images (in green), respectively. The right MB template was aligned to the left one through rigid registration. Axes indicate anterior (A), dorsal (D) and right (R) anatomical orientations. View-aligned axes orientations depicted with dot (towards viewer) and cross (away from viewer). 25 µm scale bar. (d) Mean projections of the determinant of the Jacobian determined from the displacement field obtained through the registration of the right template onto the left template. Values superior to 1 indicate that the left template should be expanded to match the right one. Values inferior to 1 indicate that it should be compressed. Voxels located outside the segmented left MB image were ignored in the average. Pixels representing the mean value of ignored voxels only were set to 1.

Appendix 1—figure 3
Relationship between ffree and τbound in different datasets.

Each dot represents the average values of ffree and τbound for a single subject. ρ indicates the Pearson correlation coefficient. The dotted lines indicate least squares affine fits. (a) Relationship between average ffree and τbound values of segmented mushroom body (MB) regions, for all subjects in Dataset 1. (b) Relationship between average ffree and τbound values of the somata region, for all subjects in Dataset 2. (c) Relationship between average ffree and τbound values in the different neuronal subtypes, for all subjects in Dataset 6.

Appendix 1—figure 4
Estimations of τbound and ffree on simulated decays.

Each dot represents the values of ffree and τbound estimated from a single simulated decay. ρ indicates the Pearson correlation coefficient. The dotted line indicates the least squares affine fit. (a) Estimations from 5,000 decays simulated by uniformly sampling ffree between 0.65 and 0.75 and τbound between 3 and 4.5 ns, independently. (b) Estimations from 5000 decays simulated by sampling correlated ffree and τbound couples on the same ranges, with a defined correlation of –0.86.

Appendix 1—figure 5
Specificity of average spatial distribution of Kenyon cell (KC) subtypes.

(a) Main steps of the computation of the average spatial distributions of the three main KC subtypes using Dataset 3. Each row shows the processing of a set of images of flies expressing a KC-specific marker (displayed in gray) and a subtype-specific nuclear marker (displayed in green). (b) Schematic illustrating the method used to assess differences between average spatial distributions of the different subtypes. (c) Comparison of the normalized image distance between average spatial distributions of identical or different subtypes, computed from different numbers of images. The graph reports mean and standard deviations. The inter-subtype distances were compared with the intra-subtype distances for the averages obtained from 20 images. The inter-subtype distances (n=60, µ=19.3±1.6%) were significantly higher than the intra-α/β (n=20, µ=8.6±1.2%; Student’s t-test, t78=26.8, Bonferroni-adjusted p=1.3×10–40), the intra-α’/β’ (n=20, µ=14.9±0.7%; Student’s t-test, t78=11.5, Bonferroni-adjusted p=5.9·10–18), and the intra-γ distances (n=20, µ=14.6±0.7%; Student’s t-test, t78=12.4, Bonferroni-adjusted p=1.0×10–19).

Appendix 1—figure 6
Measure of intra-subject and intra-hemisphere similarities of the spatial distribution of the mushroom body (MB) neuronal subtypes.

Left: Illustration of the different types of image-to-image comparisons on the MBs of two subjects. Right: Image-to-image distances based on 165 MB images of Dataset 3. The intra-subject distances were measured between all pairs of left and right MBs belonging to the same subject (n=48, n=36, and n=42 values for α/β, α’/β’, and γ, respectively). The inter-subject/intra-hemisphere distances were measured between all pairs of images of the same hemisphere belonging to different individuals (n=813, n=609, and n=790 values). The inter-subject/inter-hemisphere distances were measured between all pairs of images of different hemispheres belonging to different individuals (n=816, n=598, n=785 values). Statistical tests were performed in order to assess possible intra-subject or intra-hemisphere similarities. It revealed that α/β spatial distributions between left and right hemisphere images are more similar if they belong to the same subject than if they belong to two different subjects (Student’s t-test, Bonferroni-adjusted p=1.4×10–3, t838=–3.4). No other statistically significant effect was observed.

Appendix 1—figure 7
Spatial distribution of Kenyon cell (KC) subtype proportions.

(a) Horizontal slices (left) and posterior projection (upper right) of the subtype proportion map. The proportions of red, green, and blue indicate the proportion of α/β, α'/β', and γ neurons, respectively. The correspondence between color and proportions is indicated by the ternary diagram (lower right). Axes indicate anterior (A), dorsal (D), and right (R) anatomical orientations. The circled cross indicates the direction point away from the viewer. 25 µm scale bar. (b) Distribution of the average proportions of each subtype over all voxels. The dashed lines indicate the overall proportion of the subtypes, given by the number of neurons of the considered subtype against the total number of KCs, using the average neuron counts reported by Aso et al., 2009.

Appendix 1—figure 8
Lateralization of ffree spatial distribution in the somata area.

Left: Illustration of the different types of image-to-image comparisons on the mushroom bodies (MBs) of two subjects. Right: Comparison of single-hemisphere maps of ffree in the somata region. The ffree map distance was computed between all pairs of registered maps. We compared inter-subject/inter-hemisphere differences (n=224, µ=0.056±0.009) with inter-subject/intra-hemisphere differences (n=227, µ=0.056±0.009) and intra-subject differences (n=14, µ=0.052±0.010). We found that local differences were not significantly different when comparing the same or different hemispheres in different subjects (Student’s t-test, t449=0.13, Bonferroni-adjusted p=1.0), suggesting the absence of hemisphere-specific spatial distribution of ffree values. We found that local differences were not significantly different either when comparing different hemispheres in the same or different subjects (Student’s t-test, t236=1.51, Bonferroni-adjusted p=0.27), suggesting that subject-specific spatial distribution of ffree are not shared between both hemispheres.

Appendix 1—figure 9
Examples of distributions of ffree around the somata of α/β neurons.

Distributions of ffree for single-hemisphere images of Dataset 8, from flies subjected to unpaired and paired conditioning are shown in the left and right columns, respectively. The dotted line indicates the mean value of each distribution.

Appendix 1—figure 10
Three first moments of the within-hemisphere distributions of ffree around the somata of α/β neurons.

The mean, variance, and skewness of the distributions of ffree were computed for all single-hemisphere images in Dataset 8. The ffree mean was significantly higher in the unpaired condition (n=19, µ=0.737±0.025) compared to the paired one (n=20, µ=0.722±0.019; Student’s t-test, t37=2.04, p=4.85×10–2). The ffree variance was comparable in the unpaired condition (µ=0.050±0.008) and in the paired one (µ=0.054±0.011; Student’s t-test, t37=1.1, p=0.28). The skewness was not significantly different in the unpaired condition (µ=–0.84±0.35) and in the paired one (µ=–1.12±0.51; Student’s t-test, t37=1.98, p=5.54×10–2).

Appendix 1—figure 11
Three first moments of the within-hemisphere distributions of ffree around the somata of α/β neurons for ALAT-KD flies.

The mean, variance, and skewness of the distributions of ffree were computed for all single-hemisphere images in Dataset 10. The ffree mean was significantly higher in the unpaired condition (n=18, µ=0.685±0.024) compared to the paired one (n=17, µ=0.692±0.026; Student’s t-test, t33=0.76, p=0.45). The ffree variance was comparable in the unpaired condition (µ=0.045±0.011) and in the paired one (µ=0.045±0.011; Student’s t-test, t33=0.09, p=0.93). The skewness was not significantly different in the unpaired condition (µ=–0.56±0.32) and in the paired one (µ=–0.46±0.46; Student’s t-test, t33=0.43, p=0.43).

Appendix 1—figure 12
Average values of τfree across the different datasets.

Each value represents the within-subject average. (a) Average τfree values in the somata and calyx region (µ=0.438±0.016 ns), the peduncle (µ=0.482±0.023 ns), the vertical lobe (µ=0.485±0.016 ns), and the medial lobes (µ=0.471±0.014), for all subjects in Dataset 1 (n=5). (b) Average τfree values in somata region (µ=0.415±0.017 ns) and in the calyx (µ=0.435±0.018 ns), for all subjects in Dataset 2 (n=17). (c) Average τbound values near the somata of α/β (n=13, µ=0.386±0.012 ns), α'/β' (n=15, µ=0.0402±0.016 ns), and γ neurons (n=15, µ=0.398±0.017 ns), for all subjects in Dataset 6.

Tables

Key resources table
Reagent type (species) or resourceDesignationSource or referenceIdentifiersAdditional information
Genetic reagent (D. melanogaster)MB010BBDSCRRID:BDSC_68293
Genetic reagent (D. melanogaster)MB008BBDSCRRID:BDSC_68291
Genetic reagent (D. melanogaster)MB005BBDSCRRID:BDSC_68306
Genetic reagent (D. melanogaster)MB009BBDSCRRID:BDSC_68292
Genetic reagent (D. melanogaster)UAS-StingerBDSCRRID:BDSC_84277
Genetic reagent (D. melanogaster)UAS-mCherry-NLSBDSCRRID:BDSC_38424
Genetic reagent (D. melanogaster)UAS-LdhRNAi (HMS00039)BDSCRRID:BDSC_33640
Genetic reagent (D. melanogaster)UAS-ALATRNAi (GD9174)VDRCRRID:Flybase_FBst0459715;
VDRC Id 32681
Genetic reagent (D. melanogaster)MB-DsRedRiemensperger et al., 2005
Chemical compound, drug3-octanol (99%)Sigma-AldrichCat. #153095
Chemical compound, drug4-methylcyclohexanol (98%)Sigma-AldrichCat. #218405
Chemical compound, drugParaffine GPR RectapurVWRCat. #24679.360
Chemical compound, drugNaClSigma-AldrichCat. #S9625
Chemical compound, drugKClSigma-AldrichCat. #P3911
Chemical compound, drugMgCl2Sigma-AldrichCat. #M9272
Chemical compound, drugCaCl2Sigma-AldrichCat. #C3881
Chemical compound, drugD-trehaloseSigma-AldrichCat. #9531
Chemical compound, drugSucroseSigma-AldrichCat. #S9378
Chemical compound, drugHEPES-NaOHSigma-AldrichCat. #H7637
Software, algorithmLeica Application Suite X (v3.5.7)Leica MicrosystemsRRID:SCR_013673
Software, algorithmANTshttp://www.picsl.upenn.edu/ANTS/RRID:SCR_004757
Appendix 2—table 1
Composition of dataset 2.
SubjectsLeft imagesRight imagesTotal images
Total17141731
Appendix 2—table 2
Composition of dataset 3.
SubjectsLeft imagesRight imagesTotal images
α/β34283058
α’/β’32222850
γ36263157
Total1027689165
Appendix 2—table 3
Composition of dataset 4.
SubjectsLeft imagesRight imagesTotal images
Total19161632
Appendix 2—table 4
Composition of dataset 5.
SubjectsLeft imagesRight imagesTotal images
Unpaired158715
Paired168816
Total31161531
Appendix 2—table 5
Composition of dataset 6.
SubjectsLeft imagesRight imagesTotal images
α/β13131225
α’/β’15141428
γ15121426
Total43394079
Appendix 2—table 6
Composition of dataset 7.
SubjectsLeft imagesRight imagesTotal images
Control126612
Ldh-knockdown127512
Total24131124
Appendix 2—table 7
Composition of dataset 8.
SubjectsLeft imagesRight imagesTotal images
Unpaired1810919
Paired19101020
Total37201939
Appendix 2—table 8
Composition of dataset 9.
SubjectsLeft imagesRight imagesTotal images
Unpaired116511
Paired125712
Total23111223
Appendix 2—table 9
Composition of dataset 10.
SubjectsLeft imagesRight imagesTotal images
Unpaired1881018
Paired178917
Total35141935

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  1. Philémon Roussel
  2. Mingyi Zhou
  3. Chiara Stringari
  4. Thomas Preat
  5. Pierre-Yves Plaçais
  6. Auguste Genovesio
(2026)
In vivo autofluorescence lifetime imaging of spatial metabolic heterogeneities and learning-induced changes in the Drosophila mushroom body
eLife 14:RP106040.
https://doi.org/10.7554/eLife.106040.3