Proliferation activity in the adult rat brain following exposure to ionizing radiation.

BACKGROUND: The aim of our study was to investigate radiationinduced shortterm effects on the rat forebrain. MATERIAL AND METHODS: Adult male Wistar rats received whole body exposure with fractionated doses of gamma rays (a total dose of 3 Gy) and were investigated seven and 14 days later. Immunohistochemistry and confocal microscopy were used to determine proliferating cells derived from anterior subventricular zone (SVZa) and distributed along the subventricular zone olfactory bulb axis (SVZ OB axis). Cell counting was performed in four anatomical parts along the welldefined pathway, known as the rostral migratory stream (RMS) represented by the SVZa, vertical arm, elbow and horizontal arm. RESULTS: Different rate of cell overdistribution was found in all counted parts through the entire experiment, mostly detectable in the elbow and horizontal arm. CONCLUSION: Results suggested that radiation response of proliferating cells resides the SVZa may a play contributory role in the development of more adverse radiationinduced: late effects.