Figure 3.

Darkfield photomicrographs showing proTRH mRNA expression in the anterior, mid, and posterior levels of the PVN in control (A–C) and hypothyroid (D–F) rats and in control (G–I) and hypothyroid (J–L) mice. Note the dramatic increase in silver grains denoting proTRH mRNA in the mid and caudal level of the hypothyroid rat PVN (E and F), whereas hypothyroidism increases proTRH mRNA only in midlevel neurons in mice (K). III, Third ventricle. [Panels G–L were reproduced from A. Kádár et al: Distribution of hypophysiotropic thyrotropin-releasing hormone (TRH)-synthesizing neurons in the hypothalamic paraventricular nucleus of the mouse. J Comp Neurol. 2010;518:3948–3961 (44), with permission. © Wiley-Liss Inc.]