Localization of stimulating electrodes.

<p>Groups symbols were plotted in the same side for the sake of clarity. Abbreviations: DGLSC and DWLSC – deep gray and white layers of superior colliculus, DMPAG, DLPAG, LPAG and VLPAG – dorsomedial, dorsolateral, lateral and ventrolateral columns of the periaqueductal gray matter, DR – dorsal raphe, IC – inferior colliculus. Numbers refer to anteroposterior coordinates in relation to bregma of coronal plates of Paxinos and Watson's (1998) rat brain atlas <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0090726#pone.0090726-Paxinos1" target="_blank">[42]</a>.</p

Brain areas stimulated in controls (CTRL), sham-isolated rats (SHAM) and neonatally-isolated rats (NSI).

<p>DMPAG, DLPAG and LPAG – dorsomedial, dorsolateral and lateral columns of periaqueductal gray matter, DLSC – deep layers of superior colliculus.</p

Intensity-response threshold curves of panic-like behaviors evoked by electrical stimulations of the dorsal periaqueductal gray matter.

<p>Curves are the best-fitted logistic functions of threshold response accumulated proportions in function of the logarithm of the stimulus intensity (µA). The abscissa is in logarithmic scale. Dashed lines (–) indicate significant differences between groups (P<0.05, likelihood-ratio χ² test for curve location). Abbreviations: r – responders, n –number of stimulated rats.</p

Protocol of neonatal social isolation (NSI).

<p>PN – postnatal day, ICS – intracranial stimulation, EPM – elevated plus-maze, FST-1 – forced swimming pretest session, FST-2 – forced swimming test session.</p

Median threshold intensities (I₅₀±SE) of neonatally-isolated rats, sham-isolated rats and non-handled controls.

<p>Symbols represent values significantly different from controls (*) and sham-isolated rats (⁺) for Bonferroni's 5% criterion (likelihood ratio χ² tests for curve location).</p

Effects of neonatal social isolation on the performance of adult rats in the elevated plus-maze (<i>n</i> = 19–27) and forced swimming test (<i>n</i> = 18–24).

<p>Columns represent mean±SEM. CTRL – controls, SHAM – sham-isolated rats, NSI – neonatally-isolated rats. EAE – number of entries in enclosed arms (mean±SEM), OAE% - percent of entries in open arms, OAT% - percent of time in open arms. * P<0.005, statistically different from CTRL.</p

Primate species analyzed in the present study.

<p>*Genomic assembly information not available.</p><p>Classification according to “Wilson & Reeder’s Mammal Species of the World, 3rd Edition”, available at the Taxonomic Browser of the Smithsonian National Museum of Natural History <<a href="http://www.vertebrates.si.edu/msw/mswcfapp/msw/index.cfm" target="_blank">http://www.vertebrates.si.edu/msw/mswcfapp/msw/index.cfm</a>>.</p><p>Primate species analyzed in the present study.</p

Evolutionary relationships among the analyzed primate genera, based on the phylogeny proposed by Perelman <i>et al</i>. (2011).

<p>Between brackets, the number of repetitions comprising the <i>PER3</i> VNTR for each genus.</p

Alignment of the PER3 protein sequences from diverse mammal species, in the region corresponding to the human <i>PER3</i> VNTR.

<p>The sequences were obtained from the Ensembl Genome Browser Database (<a href="http://www.ensembl.org" target="_blank">http://www.ensembl.org</a>). Dots (.) indicate identity with human sequence. Dashes (–) indicate gaps. X’s indicate unknown or unspecified aminoacids.</p

Representation of the <i>PER3</i> human gene and the repetitive sequences associated to it.

<p>The black square represents the 18^th exon of <i>PER3</i>, where the VNTR is placed. Adapted from NCBI Map Viewer (<a href="http://www.ncbi.nlm.nih.gov/projects/mapview" target="_blank">http://www.ncbi.nlm.nih.gov/projects/mapview</a>).</p