Faculty Research 1990 - 1999


Microcephalic cerebrum with hypomyelination in the pygmy mouse (pg).

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Body-Weight, Brain: en, pa, Brain-Chemistry: ph, Calmodulin: me, Cerebellum: me, Demyelinating-Diseases: ge, px, pa, DNA: me, Female, Male, Mice, Mice-Inbred-C3H, Microcephaly: ge, pa, Motor-Activity, Myelin-Sheath: en, Organ-Weight: ph, RNA: me, SUPPORT-NON-U-S-GOVT

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Int J Dev Neurosci 1992 Oct;10(5):453-8


To determine whether somatomedin has a direct action on cerebral development instead of an indirect action of a growth hormone, we examined the central nervous system of the pygmy mouse (pg), a mutant with normal somatomedin activity. Our findings are: (A) the weights of the pg/pg cerebrum and cerebellum weighted were significantly less than those of the normal controls (pg/+), 14 and 15% less, respectively; (B) the total DNA content was reduced by 17% in the cerebrum and cerebellum of the pg/pg mouse; (C) the total RNA content was reduced in the cerebrum and cerebellum, proportional to the reduction in DNA; (D) CNPase activity was reduced selectively in the cerebrum of the pg/pg mouse by 25%; and (E) the pg/pg mice exhibited a strikingly reduced level of activity with an indistinct diurnal periodicity. Therefore, the present findings suggest that the action of somatomedin on the proliferation and maturation of glial cells might be a necessary precondition to myelin formation.

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