| First Author | Sotelo C | Year | 1983 |
| Journal | Neurosci Lett | Volume | 14 |
| Issue | Suppl | Pages | S353 (Abstr.) |
| Mgi Jnum | J:24834 | Mgi Id | MGI:72574 |
| Citation | Sotelo C, et al. (1983) Nodding, a new mutant of the mouse with cerebellar abnormalities. Neurosci Lett 14(Suppl):S353 (Abstr.) |
| abstractText | Full text of Abstract: "NODDING", A NEW MUTANT OF THE MOUSE WITH CEREBELLAR ABNORMALITIES. C. SOTELO, and J.L. GUENET, U-106 INSERM, CMC FOCH, Suresnes and Unite de Genetique des Mammiferes, Institut Pasteur, Paris (FRANCE). Nodding (nd) is a new autosomal recessive mutation affecting mainly the cerebellum. It appeared spontaneously, almost 3 years ago, in the 129/Sv strain. A severe cerebellar syndrome develops by 8 to 10 days of age. The homozygous mice become ataxic and spastic (the hind limbs being the most affected). Their heads have a continuous nodding in the anteroposterior axis. Their life span does not seem impaired. They do not improve locomotion with age. The cerebellum, although slightly reduced in size, has a normal foliation and lamination. In Nissl stained preparations the only visible alteration is the presence of a mild granule cell degeneration. In Golgi-impregnated material, all Purkinje cells (PCs) are altered; they have somewhat atrophic dendrites with numerous ectopic spines emerging from their main branches. Electron microscopic examination discloses, in mice younger than 60 days, clusters of long necked spines, deprived of innervation. In older mice, the ectopic spines remain, but most of them are innervated by hypertrophic varicosities belonging to parallel fibers and stellate axons. The enlarged terminals capped 2 to 8 profiles of spines. No other main qualitative changes of the cerebellar circuitry were observed. This new mutation seems, therefore, to affect PCs and suggests that the presence of climbing and parallel fibers, although necessary, does not suffice for the compartmentalization of the PC dendrites. Furthermore, even if the reason for the presence of free spines in young nd/nd is far from being understood, they seem to stimulate the late terminal sprouting of specific axon terminals, providing new evidence of the great capability of parallel fibers and stellate axons to adapt, in mature animals, to an increase in postsynaptic sites. |
