Journal of Neuroscience, Vol 8, 4603-4611, Copyright © 1988 by Society for Neuroscience
Evidence for the transneuronal regulation of cerebellin biosynthesis in developing Purkinje cells
JR Slemmon, D Goldowitz, R Blacher and JI Morgan
Department of Neurosciences, Roche Institute of Molecular Biology, Nutley, New Jersey 07110.
We have investigated the expression of a unique class of neuropeptides, the
cerebellins, in normal and neurodevelopmentally mutant mice. Employing HPLC
separation, gas-phase Edman sequencing, and immunocytochemistry, the normal
Balb/c mouse cerebellum is shown to contain 2 Purkinje cell-specific
neuropeptides, cerebellin and des-Ser1- cerebellin. In this strain of mouse
the cerebellins appear during early postnatal development and their
subsequent levels parallel the most dramatic period of cerebellar
development: granule cell migration and parallel fiber formation,
synaptogenesis, Purkinje cell dendritic maturation, and establishment of
adult cytoarchitecture. In mutant mice (reeler, weaver, and staggerer), in
which these early developmental events are markedly disrupted, Purkinje
cells contain much lower levels of cerebellin and des-Ser1-cerebellin. In
general there is a correlation between the formation and number of parallel
fiber-Purkinje cell synapses and cerebellin levels. For example, the
staggerer mutant, which totally lacks these synapses, is essentially devoid
of cerebellin, whereas in reeler, cerebellin seems to be dependent upon the
position of individual Purkinje cells and their ability to form contacts
with granule cells. These results indicate that granule cells can modulate
the level of cerebellin in Purkinje cells. A number of models to explain
these data are discussed.