EN
A signifi cant amount of data has emerged supporting the hypothesis that the central nervous system might monitor and modulate tumor growth. The aim of our study was to investigate whether intraperitoneal tumor growth may induce detectable changes in brain structures that are involved in the response to immune challenges. Using Fos immunohistochemistry we investigated the effect of a tumor induced by a single intraperitoneal injection of BP6-TU2 fi brosarcoma cells to male Wistar rats on the activity of selected brain structures. Twenty eight days after the tumor cells administration we found an increased Fos expression in the nucleus tractus solitarii/A2, A1 noradrenergic cells, parabrachial nucleus as well as in the hypothalamic paraventricular, supraoptic and accessory neurons. These structures are involved in the processing of signals related to immune challenges and consequent elaboration of neuro-endocrine responses. Obtained data supports the view that the signals related to peripheral tumor development might be transmitted to the brain. Further studies are necessary to reveal whether our fi ndings can be attributed to a specifi c effect of cancer or whether observed changes in the activity of neuronal structures refl ex processes that only accompany the cancer progression.