Cytogenesis in the adult monkey motor cortex: Perivascular NG2 cells are the major adult born cell type

• Published in: Journal of comparative neurology (1911) 2015-04, Vol.523 (6), p.849-868
• Main Authors: Stanton, Gregory B., Kohler, Shawn J., Boklweski, Jennifer, Cameron, Judy L., Greenough, William T.
• Format: Article
• Language: English
• Subjects: Animals; Antigens - metabolism; BrdU; Bromodeoxyuridine - metabolism; calretinin; Cell Differentiation; confocal microscopy; exercise; Female; Macaca; Macaca fascicularis; Macaca fascicularis - anatomy & histology; Macaca mulatta; Macaca mulatta - anatomy & histology; Microscopy, Confocal; Motor Cortex - cytology; Nerve Tissue Proteins - metabolism; Neuroglia - physiology; Neurons - classification; Neurons - physiology; Olig2; Organogenesis; PDGFrβ; pericytes; polydendrocytes; Proteoglycans - metabolism; Time Factors
• ISSN: 0021-9967; 1096-9861
• DOI: 10.1002/cne.23693

ABSTRACT We used confocal microscopy and immunohistochemistry (IHC) to look for new cells in the motor cortex of adult macaque monkeys that might form the cellular bases of improved brain function from exercise. Twenty‐four female Macaca fascicularis monkeys divided into groups by age (10–12 years, 15–17 years), postexercise survival periods, and controls, received 10 weekly injections of the thymidine analog, bromodeoxyuridine (BrdU) to mark new cells. Sixteen monkeys survived 15 weeks (5 weeks postexercise) and 8 monkeys survived 27 weeks (12 weeks postexercise) after initial BrdU injections. Additionally, five Macaca mulatta female monkeys (∼5.5–7 years) received single injections of BrdU and survived 2 days, 2 weeks, and 6 weeks after BrdU injections. Neural and glial antibodies were used to identify new cell phenotypes and to look for changes in proportions of these cells with respect to time and experimental conditions. No BrdU+/DCx+ cells were found but about 7.5% of new cells were calretinin‐positive (Cr+). BrdU+/GABA+ (gamma‐aminobutyric acid) cells were also found but no new Cr+ or GABA+ cells colabeled with a mature neuron marker, NeuN or chondroitin sulfate antibody, NG2. The proportion of new cells that were NG2+ was about 85% for short and long survival monkeys of which two, newly described perivascular phenotypes (Pldv and Elu) and a small percentage of pericytes (2.5%) comprised 44% and 51% of the new NG2+ cells, respectively. Proportions of NG2+ phenotypes were affected by post‐BrdU survival periods, monkey age, and possibly a postexercise sedentary period but no direct effect of exercise was found. J. Comp. Neurol. 523:849–868, 2015. © 2014 Wiley Periodicals, Inc. Within a period of 2 days to 27 weeks, most new cells (85%) generated in the adult monkey neocortex express NG2; about half are two, newly described, perivascular phenotypes. New, immature, calretinin‐positive interneurons are also found. Phenotype proportions are affected by variables of an exercise experiment.