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Sexual differentiation of the vertebrate nervous system

Nature Neuroscience volume 7, pages 1034–1039 (2004)Cite this article

Abstract

Understanding the mechanisms that give rise to sex differences in the behavior of nonhuman animals may contribute to the understanding of sex differences in humans. In vertebrate model systems, a single factor—the steroid hormone testosterone—accounts for most, and perhaps all, of the known sex differences in neural structure and behavior. Here we review some of the events triggered by testosterone that masculinize the developing and adult nervous system, promote male behaviors and suppress female behaviors. Testosterone often sculpts the developing nervous system by inhibiting or exacerbating cell death and/or by modulating the formation and elimination of synapses. Experience, too, can interact with testosterone to enhance or diminish its effects on the central nervous system. However, more work is needed to uncover the particular cells and specific genes on which testosterone acts to initiate these events.

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Figure 1: Sexual dimorphisms in the brain.
Figure 2: The conversion of testosterone into estrogen.

Debbie Maizels

Figure 3: Before birth, the SNB system is present in both male and female rats, and motor neurons have established a functional neuromuscular junction.

Debbie Maizels

Figure 4: In newly hatched zebra finches, axons from HVC reach the vicinity of their target in RA, but do not actually enter RA in significant numbers unless estrogen receptors are stimulated.

Debbie Maizels

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Authors and Affiliations

  1. Neuroscience Program, Michigan State University, East Lansing, 48824, Michigan, USA

    John A Morris, Cynthia L Jordan & S Marc Breedlove

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  1. John A Morris
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Correspondence to S Marc Breedlove.

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Morris, J., Jordan, C. & Breedlove, S. Sexual differentiation of the vertebrate nervous system. Nat Neurosci 7, 1034–1039 (2004). https://doi.org/10.1038/nn1325

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