PMC

A: Dental lamina in monophyodont mouse at E18 is composed of the dental stalk area (ds) connecting the first lower molar (M1) to the oral epithelium and rudimental successional dental lamina (arrow). Dental stalk is very short and tooth develops in the close proximity to the oral epithelium. A´: Detail of dental stalk area at E18. B: 3D reconstruction of the dental stalk area as inclined view from rostral part. B´: Detail of continuous rudimental successional dental lamina (arrow) at E18. C: Lower power of the first molar and detail of the dental stalk area (C´) at P2 with smaller successional dental lamina. D, D´: Rudimental successional dental lamina (arrow) is smaller at P2 especially at rostral and caudal end of the first molar (M1) as shown by 3D reconstruction. E, E´: Dental stalk area at P6. F, F´: The size of successional dental lamina is much smaller at P6 and it forms distinct structure just at cusps level (arrow). G, G´: The successional lamina is protruding on the lingual aspect of the second molar (M2) at E18. H, H´: The rudimental successional dental lamina of M2 became smaller at P2 and P8 (I, I´). J, J´: In contrast to the first molar area, the lamina is still visible close M2 at P10. K, K´: There is no successional lamina close the third molar at P2 as the teeth reached just early cup stage. L, L´: In the area of the third molar (M3), successional lamina was well visible at P8. M, M´: Later in development became thinner. N, N´: At P12, it was still observable at P12 in contrast to the first and the second molar area. arrow—rudimental successional dental lamina, oe—oral epithelium. Hematoxylin-Eosin. Scale bar—100 μm

Cbln2+ neurons in the dorsal horn were counted in six sections that were processed first for in situ hybridization for Cbln2, and then for immunofluorescence to visualize Lmx1b+ and Pax2+ neurons. A) The percentage of neurons that are Cbln2+ is greatest in lamina II and lamina III, less in lamina IV medial, and lowest in lamina I and lamina IV lateral. B) The percentage of Lmx1b+ neurons that are Cbln2+ is lowest in lamina IV lateral. C) The percentage of Pax2+ neurons that are Cbln2+ is lowest in lamina I and in lamina IV lateral. D) The percentage of neurons that are Lmx1b+ is lowest in lamina I and is lower in lamina IV medial and lamina IV lateral than in lamina II or lamina III. Values shown are mean ± standard error of the mean. Statistically significant differences between laminae were determined using two-tailed Mann-Whitney U tests and are indicated either by brackets indicating each comparison or, to minimize excessive crowding, above the bars showing the lamina I values. Probability is indicated by the number of asterisks (*P ≤ 0.05; ***P ≤ 0.005). The significance levels (p values) and the statistic (U) values for these comparison are provided in .

Sensitivity of LCD to laminar modulus, position and thickness and to canal size. (A) The three-factor interaction involving the laminar modulus, lamina position, and canal size. The effect of laminar position is represented by the distance between the surfaces. Deeper laminas tended to displace anteriorly, whereas the shallow laminas could displace anteriorly or posteriorly depending on the size of the canal and the laminar modulus. When the lamina was deep (bottom surface) the effects of the two other factors were smaller than when the lamina was shallow (upper surface)—that is, the top surface is steeper than the bottom surface. The effects of stiffening of the LC were larger when the canal was large than when it was small, and when the lamina was shallow than when it was deep. (B, C) Two traditional interaction plots. In the interaction between lamina thickness and canal size the effects of canal size were larger when the lamina was thin than when it was thick. Conversely, lamina thickness had a larger influence when the canal was large than when it was small. For the interaction between lamina thickness and position, lamina thickness reduced LCD when the lamina was shallow, but not when the lamina was deep. Conversely, when the lamina was thick its position had little influence on LCD, but when the lamina was thin the position had large influence. Thicker, stiffer or deeper laminas within a small canal had smaller posterior displacements and were more likely to displace anteriorly. Factors not explicitly varied were at the center levels.

(See also and , and )
(A-B’) Confocal images (longitudinal plane of lamina cartridges, 1–2 day old adults) showing the distribution of Brp (green-smFPV5) expressed in L cells (magenta-LexAop-myr-tdTOM) in the laminas of control (UAS-DIP-γ) flies or flies expressing DIP-γ in R cells (UAS-DIP-γ and GMR-GAL4). The white dotted line outlines the lamina and the yellow line separates the proximal (prox.) and distal lamina (dist.). Scale bar = 10μm.
(A and A’) Brp is restricted to the proximal lamina in control flies.
(B and B’) Streams of ectopic Brp puncta are detected throughout lamina cartridges (yellow stars in B’) when mis-expressing DIP-γ in R cells.
(C) A confocal image of a cross section through the lamina of a fly mis-expressing DIP-γ in R cells. Asterisks indicate the presumed positions of photoreceptor axons. Scale bar = 5μm.
(D) Quantification of the percentage of cartridges containing clusters of Brp puncta in the distal lamina in control flies (n= 11) and flies mis-expressing DIP-γ in R cells (n= 11). Clusters were defined as ≥3 consecutive z-stack slices containing distal Brp puncta. Only unmerged cartridges were considered in the quantification (n=25 cartridges/brain). Data are represented as a mean +/− SEM.
(E-F’) Mis-expression of DIP-γ in L cells (27G05-GAL4). Confocal images show the distribution of Brp (green-smFPV5) expressed in L cells (magenta-LexAop-myr-tdTOM) in the laminas of control flies (27G05-GAL4 alone) or experimental flies (27G05-GAL4 and UAS-DIP-γ). The region above the yellow line delineates the distal lamina (dist.). Scale bar = 10μm.
(E and E’) Brp is localized to the proximal lamina in control (27G05-GAL4) flies, occasionally with some puncta in the distal lamina. n=5 brains.
(F and F’) L cells form ectopic synapses in the distal regions of lamina cartridges (yellow stars in F’) upon mis-expression of DIP-γ in L cells. n= 5 brains.
(G) A confocal image of a cross section through the lamina of a fly mis-expressing DIP-γ in L cells. Scale bar = 5μm.
(H) Quantification of percentage of cartridges containing clusters of Brp puncta in the distal lamina in control flies (n=5) and flies mis-expressing DIP-γ in L cells (n=5). Clusters were defined as ≥5 distal Brp puncta within 5 consecutive z-stack slices of each cartridge (n=25 cartridges/brain). Data are represented as a mean +/− SEM.
(I and I’) Brp is localized to the proximal lamina in control (UAS-DIP-β) flies. n=5 brains.
(J and J’) In flies mis-expressing DIP-β in L cells (27G05-GAL4), ectopic synapses are present throughout lamina cartridges. n=7 brains.
(K) A confocal image of a cross section through the lamina of a fly mis-expressing DIP-β in L cells. Scale bar = 5μm.
(L) Quantification of percentage of cartridges containing clusters of Brp puncta in the distal lamina in control flies (n=5) and flies mis-expressing DIP-β in L cells (n=5). Clusters were defined as ≥5 distal Brp puncta within 5 consecutive z-stack slices of each cartridge (n=25 cartridges/brain). Data are represented as a mean +/− SEM.
(M and N) Putative L1-R cell synapses in flies mis-expressing DIPs-γ and ε in R cells identified by EM.
Scale bar = 200nm.
(Statistical significance- *<.05, **<.005, ***<.0005)