Zhen He* and Tucker A Patterson Pages 1 - 8 ( 8 )
Background: The present study aimed at determining pericytes, a missing component in the previously proposed living neurovascular unit (NVU) of the sexually dimorphic nucleus of the preoptic area (SDN-POA) in rats.
Materials and Mehods: Calbindin D28K-immunoreactivities (CB28-irs) were used to delineate the SDN-POA in which CD13-immunoreactivities (CD13-irs) or alpha-smooth muscle actin-immunoreactivities (αSMA-irs), two pericyte biomarkers serving the indexes of pericytes, were tagged using two adjacent brain sections (90-micron intervals). In addition, the nestin-immunoreactive (nestin-ir) cells in the SDN-POA were counted as pericytes referring to additional standards: location and nucleic and cellular morphology. Male SDN-POA volume (5.0±0.3x10-3 mm3) was significantly larger than the female (1.7±0.3x10-3 mm). Within the SDN-POA, the CD13-irs were characterized as dots, densely packed and net-like in distribution, while the αSMA-irs, excluding pipe-like or circular structures, appeared as short rod-like structures that were sparsely distributed.
Results: The immunoreactive counts of alpha-smooth muscle actin were 353±57/mm2 in males and 124±46/mm2 in females (p<0.05). On the other hand, densities of the dot-like CD13-irs were similar between males (4009±301/mm2) and females (4018±414/ mm2). There was no difference between the male and the female in the nestin-ir pericyte count in the SDN-POA.
Conclusion: In conclusion, the present study adds new information concerning pericytes to the living NVU of the SDN-POA. There is a sex difference in counting the αSMA-irs in the living NVU of the SDN-POA. Why such a difference exists warrants further investigation.
alpha-smooth muscle actin, CD13-immunoreactivity, living neurovascular unit, nestin, pericyte, sexually dimorphic nucleus
Division of Neurotoxicology, Food and Drug Administration, Jefferson, AR 72079, Office of the Director National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079