New learning and memory related pathways among the hippocampus, the amygdala and the ventromedial region of the striatum in rats

•We identified new pathways among the ventromedial area of the striatum (MrD), the hippocampus and the amygdala.•The pathways ran from the MrD to the amygdale and then to the hippocampus and back to the MrD.•Two smaller circles were between the MrD and the amygdala, and between the amygdala and the hippocampus.•The neural connections might be involved in the pathogenesis of dementia and Alzheimer disease.