This Article Full Text Full Text (PDF) All Versions of this Article: 145/1/161    most recent Author Manuscript (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yang, L. Y. Articles by Sengelaub, D. R. Search for Related Content PubMed PubMed Citation Articles by Yang, L. Y. Articles by Sengelaub, D. R.

Brain-Derived Neurotrophic Factor and Androgen Interact in the Maintenance of Dendritic Morphology in a Sexually Dimorphic Rat Spinal Nucleus

Department of Physiology (L.Y.Y.), Taipei Medical University, Taipei 110, Taiwan; and Department of Psychology (T.V., D.R.S.), Indiana University, Bloomington, Indiana 47405

Address all correspondence and requests for reprints to: Dr. Liang-Yo Yang, Department of Physiology, Taipei Medical University, 250 Wu Hsing Street, Taipei 110, Taiwan E-mail: yangly{at}tmu.edu.tw.

Testosterone regulates androgen receptor expression, soma size, and dendritic length in motoneurons of the spinal nucleus of the bulbocavernosus (SNB) in adult male rats. Brain-derived neurotrophic factor (BDNF) is also expressed in SNB motoneurons; BDNF maintains SNB soma size in castrates, and interacts with testosterone to regulate androgen receptor expression in SNB motoneurons. This study tested the hypotheses that BDNF promotes SNB dendritic lengths and that BDNF and testosterone interact to maintain dendritic morphology in SNB motoneurons. Adult male rats were castrated; and, 5 wk later, SNB motoneurons were axotomized bilaterally, and BDNF or PBS was applied via cups sutured to the cut axons. After axotomy plus BDNF or PBS application, castrates received implants of testosterone or blank capsules and were killed 24 d later. Additional males of similar age that received sham castration, sham axotomy, and a blank implant served as sham controls. Two days before death, SNB motoneurons were retrogradely labeled with cholera toxin-horseradish peroxidase, and SNB dendritic morphology was reconstructed in three dimensions. Dendritic lengths in blank-implanted castrates treated with PBS were significantly shorter than those of sham controls; treatment with either testosterone or BDNF alone failed to support dendritic length or distribution. However, treatment with both testosterone and BDNF restored dendritic morphology to the level of sham controls. Our findings demonstrate that BDNF interacts with testosterone in the maintenance of SNB dendritic arbors and support the hypothesis that dendritic morphology is regulated by trophic substances that originate in the neuromuscular periphery.

This article has been cited by other articles:

				E. N. Ottem, L. A. Beck, C. L. Jordan, and S. M. Breedlove Androgen-Dependent Regulation of Brain-Derived Neurotrophic Factor and Tyrosine Kinase B in the Sexually Dimorphic Spinal Nucleus of the Bulbocavernosus Endocrinology, August 1, 2007; 148(8): 3655 - 3665. [Abstract] [Full Text] [PDF]

				L. Katznelson, M. W Robinson, C. L Coyle, H. Lee, and C. E Farrell Effects of modest testosterone supplementation and exercise for 12 weeks on body composition and quality of life in elderly men Eur. J. Endocrinol., December 1, 2006; 155(6): 867 - 875. [Abstract] [Full Text] [PDF]

				X. Chen, R. J. Agate, Y. Itoh, and A. P. Arnold Sexually dimorphic expression of trkB, a Z-linked gene, in early posthatch zebra finch brain PNAS, May 24, 2005; 102(21): 7730 - 7735. [Abstract] [Full Text] [PDF]