Objective:To study the whole-brain distribution of vasoactive intestinal peptide(VIP)-positive neurons in the mouse brain and provide assistance for anatomical and functional studies of VIP neurons.Methods:VIP-Cre::Ai47 mice were used to label VIP neurons in the whole brain.Then,fluorescent imaging of the whole brain slices from VIP-Cre::Ai47 mice was calibrated using the standard brain map.Finally,the distribution density of VIP-positive neurons in different regions of the whole brain was statistically analyzed.Results:The overall distribution densities of VIP neurons in the cortex,olfactory bulb,and hippocampus were all greater than 5 neurons/mm2,and the distribution densities varied greatly in different subregions.The overall distribution density of VIP in the amygdala in the subcortical region was 4 neurons/mm2,and the distribution densities of VIP in the thalamus,hypothalamus,midbrain,and hind-brain regions were less than 2 neurons/mm2 on average,except for that in the supraoptic nucleus of the hypothalamus,where the density of VIP neuron distribution reached 20 neurons/mm2.Conclusion:VIP-positive neurons are mainly distributed in the cortex,hippocampus,and amygdala,which are highly associated with cognition and affection,and are rarely distributed in the thalamus and midbrain.These results suggest that VIP neurons play an essential role in emo-tional and cognitive functions.

Objective:To study the whole-brain distribution of vasoactive intestinal peptide(VIP)-positive neurons in the mouse brain and provide assistance for anatomical and functional studies of VIP neurons.Methods:VIP-Cre::Ai47 mice were used to label VIP neurons in the whole brain.Then,fluorescent imaging of the whole brain slices from VIP-Cre::Ai47 mice was calibrated using the standard brain map.Finally,the distribution density of VIP-positive neurons in different regions of the whole brain was statistically analyzed.Results:The overall distribution densities of VIP neurons in the cortex,olfactory bulb,and hippocampus were all greater than 5 neurons/mm2,and the distribution densities varied greatly in different subregions.The overall distribution density of VIP in the amygdala in the subcortical region was 4 neurons/mm2,and the distribution densities of VIP in the thalamus,hypothalamus,midbrain,and hind-brain regions were less than 2 neurons/mm2 on average,except for that in the supraoptic nucleus of the hypothalamus,where the density of VIP neuron distribution reached 20 neurons/mm2.Conclusion:VIP-positive neurons are mainly distributed in the cortex,hippocampus,and amygdala,which are highly associated with cognition and affection,and are rarely distributed in the thalamus and midbrain.These results suggest that VIP neurons play an essential role in emo-tional and cognitive functions.