Fig. 2

ERα receptor distribution. a Cerebral occipital cortex - all layers of the cortex contained ERα immunoreactivity, except for the outer molecular layer (layer I). In the column in the middle, from the top ERα immunohistochemistry is visualized in layer III, in the middle DAPI nuclear staining and at the bottom the merged images. Arrows point at nuclei of ERα positive neurons, arrowheads at negative glial cells and asterisk at a blood vessel. b In the white matter corpus callosum (cc), very few or no ERα expressing nuclei were found. c ERα receptor distribution in the hippocampus - in the hippocampal area CA1, ERα expression in the neuronal cytoplasm and fibers were found. d ERα receptor distribution in the cerebellum - most nuclei expressed ERα in the cerebellum. Immunoreactivity was found in the molecular (mol layer) and granular layers (gran layer), and in the Purkinje cells (Pc). In addition, expression was observed in the Medial cerebellar nuclei (Med). e and f ERα receptor distribution in the Pontine nuclei (Pn) and Inferior olive (IO) – Pontine nuclei is a part of the brainstem that conducts signals from the brain down to the cerebellum and medulla, and tracts that carry the sensory signals up into the thalamus. Intense neuronal nuclei expression was found in the Pn. The inferior olive is a structure found in the medulla oblongata and is known to coordinate signals from the spinal cord to the cerebellum to regulate motor coordination and learning. The nuclei of IO showed ERα immunoreactivity. Insert: arrows point at immunoreactive neuronal cell nuclei, arrow heads point at negative glial cells. g and h ERα receptor distribution in the Supraoptic nucleus (SO) and in the Island of Calleja (ICj) - in the supraoptic nucleus), a nucleus of neurosecretory cells (oxytocin and vasopressin producing) in the hypothalamus, intense ERα immunohistochemistry was observed. In the ventral striatum, a region of the brain which is part of the limbic system, the Island of Calleja, a group of neural granule cells, is situated. Here, the densely packed group of cells showed intense ERα immunoreactivity. Immunoreactivity was also seen in the olfactory tubercle (Tu)