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A study of the effects of pubertal induction with monthly testosterone injections in young boys aged 12 to 17 years receiving glucocorticoids demonstrated no effects on bone density or bone age advancement but improved muscle strength. A study reviewing the effects of AR antagonism in presymptomatic SOD1- G93A male mice, noted an earlier onset of myofiber atrophy when compared with female mice. It is hypothesized that loss of function of ARs located at spinal motor neurons, skeletal muscles, and certain cranial nerves increases axonal vulnerability to various insults, contributing to disease pathogenesis . SBMA is caused by CAG expansion at the first exon of the androgen receptor gene. Spinal and bulbar muscular atrophy (SBMA), also known as Kennedy disease, is an X-linked neuromuscular disease characterized by loss of lower motor neurons located in the brainstem and spinal cord. One study highlighted an association between decreased free testosterone levels and an increased risk of aneurysmal subarachnoid hemorrhage (SAH) in women .
Moreover, larger cohort sizes and multiple routes of administration in addition to transdermal testosterone gels should be explored. Moreover, treatment of EAE mice with 5α-DHT resulted in improved clinical scores, and reduced spinal cord gliosis and inflammation . The differences in cytokine production between males and females could be due to a testosterone-induced shift in the immune system toward Th2 immunity. Interestingly, MENT is not a substrate for the 5α-reductase enzymes and thus does not stimulate the growth of the prostate, a possible concern with androgen therapy. Complete androgen insensitivity is referred to as Tfm (for testicular feminization mutation) and affected individuals are males with a feminine appearance, internal and poorly developed testicles. The discovery of an AR mutation in mice in 1970 by Lyon and Hawkes provided an excellent model for the study of CAIS.
In the evolutionary tree, myelin first appears in Chondrichthyan Gnathostomes, cartilaginous fish, about 440 million years ago 36,37. In addition to mechanical support to axons, myelin provides metabolic support, regulates repair and plasticity and, most importantly, allows fast conduction of action potential . Moreover, astrocytes have been shown to contribute to remyelination as their presence can facilitate the repair of demyelinating lesions by host oligodendrocytes 28,29,30,31. Intercellular connections between astrocytes and oligodendrocytes are vital for the proper functioning of oligodendrocytes.
Unlike myelination, carried out during development, for which a close association exists between axon diameter and myelin thickness, the thickness of the myelin sheath during remyelination is independent of the diameter of the axon. Rapid remyelination is important to restore metabolic support to the axon, to prevent axon degeneration and subsequent neurological disability, and also to reconstruct the nodes of Ranvier, where are located the voltage-dependent sodium channels necessary for saltatory conduction . In agreement with this concept, most OPCs generated during the early postnatal period, when the greater part of CNS myelination takes place, differentiate into mature and myelinating oligodendrocytes. The knowledge of this process is of major importance as spontaneous regeneration of myelin (also called "remyelination") following demyelinating events taking place in the adult CNS. The inflammatory process is driven by a T-cell-mediated immune reaction that leads to attacks against both the myelin sheaths and the oligodendrocytes. For example, in MS, the loss of this communication due to oligodendrocyte death and demyelination leads to a considerable degeneration of axons and astrocytic gliosis 47,48.
In vitro studies showed that mature oligodendrocytes are able to form myelin like membranes and myelin sheaths that enwrap axons as they do in vivo 4,18,19 Indeed, refined MRI techniques have revealed that the severity of disease symptoms in multiple sclerosis (MS) patients is linked to gray matter myelin loss . During development, OPCs first appear around embryonic day 12.5 in mice, almost the same time in the ventral region of spinal cord named as pMN domain and as well as ventral brain region median ganglionic eminence. Immuno-histologically, OPCs can be identified by the expression of membranous proteins, platelet-derived growth factor receptor alpha (PDGFRα), A2B5, proteoglycan sulfate (NG2) as well as transcription factor Olig1/2, sox2, Nkx2.2. Each category is morphologically distinct; OPCs are bipolar, migratory in nature and proliferative cells while mature oligodendrocytes are highly branched cells specialized to make myelin sheets.
This androgen is responsible for masculine features and fertility in males while having positive effects on bone density, lean mass, mood, and libido in females. Testosterone is the most potent androgen, produced primarily by the Leydig cells in the testis. Androstenedione has moderate androgenic activity, is produced by adrenal glands and gonads, and is derived from DHEA.
It is also involved in the regulation of sexual behaviour and the formation of sexual preferences . Damage to the prefrontal cortex can cause changes in sexual behaviour, such as increased impulsivity and risk-taking . This brain region is responsible for decision-making, impulse control, and social behaviour. It also contains the autonomic nervous system responsible for heart rate and blood pressure functions. For example, research has found that the brains of gay men and straight women are similar, while the brains of lesbian and straight men also share certain features . It serves as a foundation for future research and underscores the significance of interdisciplinary approaches in unravelling the complexities of human sexuality.