From the accompanying excel resource sheet, all plots presented in this study can be recreated. In addition, the reader can query the dataset with his own questions, by creating pivot tables. The workflow, how to create such a pivot table in excel is described here. (1) After opening the excel sheet, navigate to the ‘RAW DATA’ tab. Then go to the ‘Insert’ tab and insert a pivot table. In the subsequent pop-up dialogue, make sure the entire range of the dataset is selected and click ‘OK’. Next, (2) set Filters for at least the tracing type (AAV or RV), as RV and AAV results do not share the same values. Optionally, you can set filters for the Genotype (Camk2a-Cre and Gad2-Cre) and from which part of the insula the tracings should be selected (aIC, mIC, pIC). Depending on your question and how you want the data to be plotted, you have to choose which values to use (3). In the manuscript we present the data as percent of total output or input, respectively. Additionally, we provide cell density and pixel density measurements for RV and AAV tracings, respectively. Important: (4) Because of the raw data structure, it is necessary to use ‘sum of percent_total_input or output’. Double-check that the percentages add up to 100% in the grand total fields. For density measurements, please use ‘average of’. (5) Depending on how you want the data to be arranged, drag and drop the fields into either columns or rows window. For example if you are interested in inputs from a region along the anterior-posterior axis, put ‘Bregma’ into either Columns or Rows. Then select the entire pivot table and insert a chart.