Biomaterial Database

A qualitative and quantitative light microscopic study of the inferior olivary complex of normal, reeler, and weaver mutant mice. 1985

G J Blatt, and L M Eisenman

In the normal mouse (+/+; +/rl) cerebellar Purkinje cells (PCs) are aligned in a monolayer and provide the main targets for incoming olivocerebellar climbing fibers (CF). In the neurological mutants, homozygous reeler (rl/rl), homozygous weaver (wv/wv) and heterozygous weaver (wv/+), cerebellar abnormalities exist in which many PCs are either missing or displaced. Therefore, it is of interest of determine if the inferior olivary complex (IO) in these mutants is also abnormal. This report concerns results obtained from a light microscopic study of the inferior olivary complex. Counts of IO cells revealed apparent differences in the IO in homozygous reeler when compared to normal littermates. Whereas in the normal mouse there are approximately 37,000 IO cells and clearly defined olivary subdivisions, the IO of the homozygous reeler has a 22.6% reduction in IO cells (mean = 28,770) and indistinct borders between the major olivary subdivisions. With regard to the heterozygous and homozygous weaver, surprisingly the IO morphology and cell numbers are similar to that of the wildtype mouse even though the animals have only 86% (wv/+, mean = 158,155) and 72% (wv/wv, mean = 131,882), respectively, of the normal numbers of PCs (+/+, mean = 183,857). Purkinje cell counts revealed that the midline vermal region is the most affected area in the cerebellum in wv/+ and wv/wv whereas counts in the lateral hemisphere are near normal. The PC/IO ratio in the homozygous weaver is approximately 3:1 as compared to 5:1 in the wildtype mouse. Recent electrophysiological findings in wv/wv indicate that PCs are multiply innervated by CFs. Since a transient phase of multiple innervation is normal in the immature rat, the situation in the adult homozygous weaver may represent a retention of this immature state. A factor which may play a role in this is the loss of parallel fiber (PF)-PC synapses resulting from massive postnatal granule cell death. An hypothesis suggesting an intrinsic PC time-dependent mutant gene effect is presented to account for the differences in the loss of Purkinje cells between wv/wv and wv/+ and between different regions of the cerebellum.

UI	MeSH Term	Description	Entries
D008818	Mice, Neurologic Mutants	Mice which carry mutant genes for neurologic defects or abnormalities.	Lurcher Mice,Nervous Mice,Reeler Mice,Staggerer Mice,Weaver Mice,Chakragati Mice,Chakragati Mouse,Lurcher Mouse,Mice, Neurological Mutants,Mouse, Neurologic Mutant,Mouse, Neurological Mutant,Nervous Mouse,Neurologic Mutant Mice,Neurological Mutant Mouse,Reeler Mouse,Staggerer Mouse,Weaver Mouse,ckr Mutant Mice,Mice, Chakragati,Mice, Lurcher,Mice, Nervous,Mice, Neurologic Mutant,Mice, Reeler,Mice, Staggerer,Mice, Weaver,Mice, ckr Mutant,Mouse, Chakragati,Mouse, Lurcher,Mouse, Nervous,Mouse, Reeler,Mouse, Staggerer,Mouse, Weaver,Mutant Mice, Neurologic,Mutant Mice, ckr,Mutant Mouse, Neurologic,Neurologic Mutant Mouse
D009847	Olivary Nucleus	A brainstem nuclear complex. in the hindbrain, also referred to as the olivary body. The olivary nuclear complex is a part of the MEDULLA OBLONGATA and the PONTINE TEGMENTUM. It is involved with motor control and is a major source of sensory input to the CEREBELLUM.	Basal Nucleus, Olivary,Nucleus Basalis, Olivary,Olivary Body,Olivary Complex,Olivary Nuclei,Complex, Olivary,Nucleus, Olivary,Nucleus, Olivary Basal,Olivary Basal Nucleus,Olivary Bodies
D011689	Purkinje Cells	The output neurons of the cerebellar cortex.	Purkinje Cell,Purkinje Neuron,Purkyne Cell,Cell, Purkinje,Cell, Purkyne,Cells, Purkinje,Cells, Purkyne,Neuron, Purkinje,Neurons, Purkinje,Purkinje Neurons,Purkyne Cells
D006579	Heterozygote	An individual having different alleles at one or more loci regarding a specific character.	Carriers, Genetic,Genetic Carriers,Carrier, Genetic,Genetic Carrier,Heterozygotes
D006720	Homozygote	An individual in which both alleles at a given locus are identical.	Homozygotes
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus