Majority of CTB-labelled neurons in the ventral olfactory nucleus (VON) are GABAergic. (a) In situ hybridization for VGluTs and GAD65/67 mRNAs alongside adjacent slice images of cholera toxin B subunit (CTB)-labelled ventral olfactory nucleus (VON) neurons. Scale bars: 100 μm. AON, anterior olfactory nucleus; VON, ventral olfactory nucleus; OT, olfactory tubercle. (b) Double fluorescent labelling of CTB and VGluT1 (upper panels) or GAD65/67 (lower panels) mRNAs. Scale bar: 100 μm. (c) Percentage of VGluT1 or GAD65/67 mRNA(+) cells among CTB-labelled cells in the VON. Data are shown as average ± SD with individual data plots. (d) Soma size of VGluT1 or GAD65/67 mRNA(+) CTB-labelled cells in the VON. Data are shown as average ± SD. ***p < 0.001.