Distribution of mesencephalic trigeminal nucleus neurons in the reeler mutant mouse.

BACKGROUND: Reeler (gene symbol, rl) is an autosomal recessive mutation occurring in mice and characterized by the abnormal positioning of neurons in the central nervous system. In this mutant, however, the cytoarchitecture of the peripheral nervous system is normal, implying that the reeler genetic locus does not affect migration of neurons in the peripheral system. Mesencephalic trigeminal nucleus (Me5) neurons are unique in that they are derived from the neural crest like other neurons in the peripheral nervous system, but enter secondarily into the central nervous system.

MATERIALS AND METHODS: Me5 neurons were labeled by injecting horseradish peroxidase or Fast Blue into the temporal muscle of normal and reeler mice to determine whether the migration of these neurons is affected by the reeler genetic locus.

RESULTS AND CONCLUSIONS: Labeled Me5 neurons of the reeler mouse were more widely scattered in comparison with their normal counterparts, suggesting that the reeler genetic locus affects migration of neurons which originate in the neural crest and then migrate into the central nervous system.