EN
INTRODUCTION: A noninvasive method of mapping cortical activation in the same animal before and after behavioral training for assessing experience-dependent cortical plasticity is of great value. Previously, we mapped changes in cortical representation of vibrissae involved in behavioral training with 2-deoxyglucose (2-DG). We wanted to replicate the 2-DG results with ISOI. AIM(S): The aim of the experiments was to find a protocol of vibrissae stimulation for the ISOI from the barrel cortex, which could provide constant signal in temporally separated recordings and enable visualization of plastic changes. METHOD(S): Two subsequent ISOI were performed with 6 days interval. Conditioning consisted of 3 daily sessions of 40 trials of manual stimulation of row B vibrissae on one side of the snout coupled with a mild tail shock. 24 hours after the last conditioning session the second ISOI was performed. Two protocols of vibrissae stimulation during ISOI were tested. In the first protocol 5-ms deflections of B1 vibrissa were applied for 1 s with frequency of 5 Hz (this protocol was used in earlier studies of experience-dependent cortical plasticity seen after whisker deprivation). In the second protocol 5-ms deflections of B1 vibrissa were applied for 6 s with frequency of 10 Hz. Additionally, after second ISOI a 2-DG mapping was performed in order to confirm plasticity in the somatosensory cortex. Using 2-DG method a comparison was performed between left (involved during conditioning) and right (not involved) vibrissae representation. RESULTS: The paired ISOI using the first protocol (1 s/5 Hz) of vibrissae stimulation revealed no change of the B1 vibrissa representation after conditioning, a result that is inconsistent with 2-DG maps. ISOI in which the second vibrissae stimulation protocol (6 s/10 Hz) was applied showed expansion of cortical representation of vibrissa stimulated during conditioning. CONCLUSIONS: Different protocols are suitable for different types of experience-dependent cortical plasticity. FINANCIAL SUPPORT: Project supported by National Science Centre, Poland (DEC-2012/05/D/NZ3/00994).