Switchback and second refractory experiment body weight profiles.

<p>Body weights of Siberian hamsters that were kept in long days (LD) or short days (SD) for 14 weeks, 39 weeks. After 16 week a group of hamsters was switched from SD to LD (SWB22 blue dashed line) and culled alongside a control group () after 22 weeks. Data are expressed as mean±SEM.</p

First refractory experiment body weight profiles.

<p>Body weights of Siberian hamsters that were kept in long days (LD) or short days (SD) for 18 weeks (LD18 black line, SD18 black dashed line), 25 weeks (LD25 blue line, SD25 blue dashed line), or 37 weeks (LD37 red line, SD37 red dashed line). Data are expressed as mean±SEM.</p

Somatostatin and Melanocortin 3 receptor gene expression in hypothalamus.

<p>Analysis and representative sections of (A) <i>Srif</i> expression and (B) <i>Mc3r</i> expression in the arcuate nucleus (ARC) and (C) <i>Mc3r</i> expression in the ventromedial hypothalamus (VMH) of Siberian hamsters that had been kept in LD or SD photoperiod for 18, 25 or 37 weeks. Data are presented as means ± SEM. **p<0.01 and ***p<0.001.</p

Overview of the genes of neuronal (standard font) and ventricular ependymal cell (bold font) origin and their response to extended SD photoperiod exposure relative to their LD control groups.

<p>Arrows indicates direction and strength of change in gene expression: ↑ small, ↑↑ moderate and ↑↑↑ large increase in gene expression; ↓ small and ↓↓ moderate decrease in gene expression;  =  no change in gene expression; n/a gene expression was not available.</p

Type 2 and type 3 deiodinase gene expression in ventricular ependymal cells of switchback and refractory hamsters.

<p>Analysis and representative sections of (A) <i>Dio2</i> and (B) images of <i>Dio3</i> expression in the tanycytes of hamsters that had been kept in LD or SD for 14 weeksor 39 weeks, and hamsters that had been switched from SD to LD after 16 weeks and were culled after 22 weeks (SWB22) alongside an LD control group. Data are presented as means ± SEM and significance was defined as *p<0.05 and ***p<0.001. Images shown for <i>Dio2</i> expression are from the 14 week and 22 week housed hamsters. Images shown for <i>Dio3</i> expression are from the 14, 22 and 39 week housed hamsters.</p

TSH receptor and nestin gene expression in ventricular ependymal cells of switchback and refractory hamsters.

<p>Analysis and representative sections of (A) <i>Tsh-r</i> and <i>nestin</i> (B) in the tanycytes of hamsters that had been kept in LD or SD for 14 weeks or 39 weeks, and hamsters that had been switched from SD to LD after 16 weeks and were culled after 22 weeks (SWB22) alongside an LD control group. Data are presented as means ± SEM and significance was defined as *p<0.05 and ***p<0.001.</p

Type 2 deiodinase and thyroid hormone transporter MCT8 expression in ventricular ependymal cells.

<p>Analysis and representative sections of (A) <i>Dio2</i> and (B) <i>Mct8</i> expression in the ependymal cells of Siberian hamsters that had been kept in LD or SD photoperiod for 18, 25 or 37 weeks. Expression was normalized to LD 18 week hamsters. Data are presented as means ± SEM and significance was defined as *p<0.05 and ***p<0.001.</p