The Topographic Characteristics Of Doublecortin-expressing Neurons In Chinese Tree Shrew Forebrain

Objective: To observe the spatiotemporal expression patterns of immature neurons marked by Doublecortin(DCX)in the forebrain of Chinese tree shrew.Comparison of similarities and differences between rodents and primates in the forebrain of Chinese tree shrewMethods: we characterized DCX immunoreactivity(IR)in the forebrain of Chinese tree shrews aged from 2 month-to 6 years-old(n=17).DCX+ cells were present in the OB,SVZ,SGZ,the piriform cortex over layer II and the amygdala around the PLN.Then,we characterized DCX immunofluorescence(IF)with Neu N and Ki67.Results: The numerical densities of DCX+ neurons were reduced in all above neuroanatomical regions with age,particularly dramatic in the DG in the 5-6 years-old animals.DCX+ neurons were partially co-labeled with Neu N,but not significantly co-labeled with Ki67.Conclusion: Thus,DCX+ neurons are present in the two established neurogenic sites(SVZ and SGZ)in the Chinese tree shrew as seen in other mammals.DCX+ cortical neurons in this animal exhibit a topographic pattern comparable to that in mice and rats,while these immature neurons are also present in amygdala,concentrating around the PLN as seen in primates and some nonprimate mammals.