Relationship between habenular volume and laterality Index.

<p>(A–D) Plots showing the relation between habenular volume (rHb+lHb, in mm³×10⁻³) and asymmetry (rHb - lHb, in mm³×10⁻⁴) in different species of teleosts. Data corresponding to different species have been presented in two rows, each representing sex (female = top; male = bottom), and grouped into two columns according to the size of individuals (left = smaller fish; right = larger fish). Groups of dots sharing the same colour correspond to individuals of a single species, and the line of equivalent colour depicts the linear regression of that group. The abbreviation for each species is given on either left or right sides of the regression line, according to the code given in E. (E) Pearson's correlation coefficient (r) and p values (in parenthesis) for each species and sex. The asterisk indicates the presence of statistically significant correlation between habenular volume and asymmetry (p<0.05).</p

Asymmetry and laterality index of the habenulae in teleosts.

<p>Abbreviations: L (Left), Max (maximum value), Min (minimum value), R (Right).</p

Comparative distribution of left and right habenular efferents in the interpeduncular nucleus of teleosts.

<p>(A) Drawings of adult male individuals belonging to different teleost species, placed in the context of a cladogram of the teleost lineage according to Nelson <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035329#pone.0035329-Nelson1" target="_blank">[28]</a>. (B) Schematic representation of a teleost brain (e.g. D rerio), showing the procedure of differential dye labelling in left (DiD, red) and right (DiO, green) Hb, and the location and orientation of the histological sections shown in B′, and C–I. (B′) Schematic drawing of a coronal section at the level of the IPN in a teleost brain (e.g. D rerio), showing dorsal and ventral aspects of the IPN in red and green, respectively. (C–I) Confocal microscopy images of 100 µm-thick vibratome sections taken according to B′, with dorsal to the top. The boundaries of dorsal (dIPN) and ventral (vIPN) IPN domains have been depicted with dashed lines. Panels C to I correspond to efferents labelled after placing crystals of DiD in the left Hb. Panels C′ to I′ correspond to efferents labelled after placing crystals of DiO in the right Hb. Abbreviations: A (anterior), D (dorsal), P (posterior), TeO (Optic Tectum), V (ventral). Scale bars: 100 µm.</p

Relationship between body weight and habenular laterality Index.

<p>(A–D) Plots showing the relation between the weight of individual fish (in grams, g) and the score of habenular laterality index (LI) in different species of teleosts. Positive and negative scores of LI indicate right- and left- sided direction of habenular asymmetry, respectively. Data corresponding to different species have been presented in two rows, each representing a sex (female = top; male = bottom), and grouped into two columns according to the size of individuals (left = smaller fish; right = larger fish). Groups of dots sharing the same colour correspond to individuals of a single species, and the line of equivalent colour depicts the linear regression of that group. The abbreviation for each species is given on either left or right sides of the regression line, according to the code given in E. (E) Pearson's correlation coefficient (r) and p values (in parenthesis) for each species and sex. The asterisk indicates the presence of statistically significant correlation between body weight and habenular LI (p<0.05).</p

Cytoarchitectonic organisation of the habenulae in teleosts.

<p>(A) Drawings of adult male individuals belonging to different teleost species, placed in the context of a cladogram of the teleost lineage according to Nelson <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035329#pone.0035329-Nelson1" target="_blank">[28]</a>. (B) Schematic representation of a teleost brain (e.g. D rerio), showing the location and orientation of histological sections shown in C–I. (C–I) Photomicrographs of cresyl-violet stained 10 µm-thick coronal sections taken at a midpoint between rostral and caudal ends of the Hb as shown in B. Each panel corresponds to a single species, as indicated in the letter code of the left diagram. C′ is a magnification of the square region depicted in C. Dorsal is to the top, and left is to the left. Arrowheads point to the subhabenular sulcus. Asterisks indicate the position of the dorsal-most neuropil region of the dorsal habenulae that is surrounded by a shell of cell bodies in some species. Abbreviations: A (anterior), D (dorsal), dHb (dorsal Hb), L (left), P (posterior), R (right), TeO (Optic Tectum), V (ventral), vHb (ventral Hb). Scale bars: 50 µm.</p

Social vs Non-social differences in the laterality index of the habenulae in teleosts.

<p>Social vs Non-social differences in the laterality index of the habenulae in teleosts.</p

Comparative analysis of volumetric asymmetry in the habenulae of teleosts.

<p>(A) Drawings of adult male individuals belonging to different teleost species, placed in the context of a cladogram of the teleost lineage according to Nelson <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035329#pone.0035329-Nelson1" target="_blank">[28]</a>. For each species, the corresponding panels from columns B to F are aligned horizontally. (B) Schematics of habenular cytoarchitecture obtained from the cresyl-violet stained coronal sections of the Hb shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035329#pone-0035329-g001" target="_blank">Figure 1</a>. (C) Volumetric models of the Hb as seen dorsally, with anterior to the top. Volumes of the left and right Hb have been differentially coloured in red and green, respectively. (D) Colour code diagram indicating the presence of statistically significant laterality of habenular volume at the population level ([R-L]≠0). For each box, the presence of left- or right- directional asymmetries, and the corresponding p values, have been coloured according to the colour scale given below. Vertical lines and asterisks placed on the left side of some pairs of boxes indicate sex-specific significant differences in habenular asymmetry (* = p<0.05; ** = p<0.01). (E) Box plots indicating the scores of habenular Laterality Index for each species and sex. Positive and negative values indicate right- and a left- sided laterality of habenular volume, respectively. Values reveal the strength and directionality of habenular asymmetry at the population level. The vertical line with asterisks placed indicates sex-specific significant differences in Laterality Index (** = p<0.01). (F) Box plots indicating the absolute values of Laterality Index (abs-LI) for each species and sex, which reveal the strength of habenular asymmetry at the individual level. For each plot shown in E and F, the box depicts the interquartile range containing 50% of the data around the median (vertical line inside the box), and the whisker depicts maximum and minimum vales. Abbreviations: A (anterior), Asym (asymmetry), Cyto (cytoarchitecture), D (dorsal), F (females), L (left), M (males), P (posterior), R (right), V (ventral). Scale bar: 100 µm for column B, and 200 µm for column C.</p

Sex-specific differences in volume, asymmetry and laterality index of the habenulae in teleosts.

<p>Abbreviations: male>female [m], female>male [f].</p