The anorectic anx/anx mouse displays signs of astrogliosis in the hypothalamus

Introduction: Anorexia Nervosa is a serious psychiatric condition that has been suggested to have a neuroimmunological mechanism as a part of the pathophysiology. Hypothalamic inflammation occurs in an anorectic animal model called the anx/anx mouse in the form of up-regulation of inflammatory markers and activated microglia. However, neuroinflammation based on astrogliosis has not been studied in this model. Aims: This study aimed at establishing if astrogliosis occurs in the hypothalamus of the anx/anx mouse model. Material and Methods: A total of 8 animals 4 of each genotype (anx/anx and +/+) at postnatal day 21 were employed. The brains were dissected, the hypothalamus sectioned and immunohistochemistry was performed with tyramide signal amplification method using glial fibrillary-acidic protein (GFAP) as a marker for astrogliosis. The GFAP immunofluorescence in anx/anx and +/+ mice was measured in different hypothalamic areas involved in the regulation of food intake. Results: A statistically significant increase of GFAP-marked astrocytes was present in the paraventricular nucleus (p=0.04) and arcuate nucleus (p=0.03) of the anx/anx mouse in comparison to +/+ mice. There was no significant increase of GFAP-marked astrocytes in the medial preoptic area (p=0.07). Conclusions: The anx/anx mouse displays signs of astrogliosis in the hypothalamus suggesting an important role for astrocytes in anorexia. The underlying cause for the astrogliosis present in the hypothalamic regions in the anx/anx mouse is not known and needs to be further studied.