ESTROGEN-RECEPTOR OCCURRENCE IN THE MALE-MOUSE BRAIN - MODULATION BY PATERNAL EXPERIENCE

PATERNAL behaviour (pup-searching and retrieving of pups) was studied In male house mice with different experience in pup care and oestrogen receptor immunoreactive (ER-IR) cells were localized and quantified i n their brains. Experience with pups induced paternal behaviour and co rrelated with (a) the occurrence of ER-IR cells in the bed nucleus of the stria terminalis, hippocampus, subiculum, lateral septal nuclei, e ntorhinal and piriform cortex, (b) increased numbers of ER-IR cells in the medial preoptic area and arcuate nucleus of the hypothalamus, and (c) decreased presence of ER-IR cells in the periventricular grey of the midbrain. The data indicate oestrogen receptor modulation in the m ale brain and suggest that oestrogen binding in distinct brain areas i s involved in the regulation of paternal behaviour.