ABSTRACT
We examined the axonal transport of two strains of herpes simplex virus 1 (HSV-1) within the central nervous system of cebus monkeys. Each strain was injected into the "arm area" of the primary motor cortex. One strain, HSV-1(McIntyre-B), was transported transneuronally in the retrograde direction. It infected neurons at sites known to project to the arm area of the primary motor cortex (e.g., ventrolateral thalamus). In addition, "second-order" neurons were labeled in the deep cerebellar nuclei (dentate and interpositus) and in the globus pallidus (internal segment). This result supports the concept that the arm area of the primary motor cortex is a target of both cerebellar and basal ganglia output. In contrast, the other strain, HSV-1(H129), was transported transneuronally in the anterograde direction. It infected neurons at sites known to receive input from the arm area of the primary motor cortex (e.g., putamen, pontine nuclei). In addition, "third-order" neurons were labeled in the cerebellar cortex (granule and Golgi cells) and in the globus pallidus (largely the external segment). Our observations suggest that strain differences have an important impact on the direction of transneuronal transport of HSV-1. Furthermore, it should be possible to examine the organization of cerebellar and basal ganglia loops with cerebral cortex by exploiting transneuronal transport of HSV-1 and virus strain differences.
Subject(s)
Brain/microbiology , Neurons/microbiology , Simplexvirus/classification , Animals , Biological Transport , Brain/cytology , Brain/metabolism , Cebus , Cerebellar Cortex/cytology , Cerebellar Cortex/metabolism , Cerebellar Cortex/microbiology , Cerebral Cortex/cytology , Cerebral Cortex/metabolism , Cerebral Cortex/microbiology , Globus Pallidus/cytology , Globus Pallidus/metabolism , Globus Pallidus/microbiology , Motor Cortex/cytology , Motor Cortex/metabolism , Motor Cortex/microbiology , Neurons/cytology , Neurons/metabolism , Putamen/cytology , Putamen/metabolism , Putamen/microbiologyABSTRACT
Dendritic spine density was determined quantitatively in 35-day-old neostriatal transplants and age-matched control tissue. Transplanted spiny I neurons showed significant decreases in spine density and in number of proximal dendrites. These differences may be due to aberrant maturation of transplanted neurons.
Subject(s)
Caudate Nucleus/transplantation , Dendrites/physiology , Putamen/transplantation , Animals , Caudate Nucleus/cytology , Caudate Nucleus/embryology , Graft Survival , Putamen/cytology , Putamen/embryology , RatsABSTRACT
Embryonic neostriatal cell suspensions were transplanted into intact or kainic acid-lesioned neostriata of adult host rats. These transplants survived and were sacrificed at 34-78 days posttransplantation. Nissl and Golgi preparations revealed neurons present within the transplants. Neurons with abundant dendritic spines (Spiny type I) were most frequent, but those with fewer spines (Spiny type II) and smooth dendrites (Aspiny II and III) were also present. These results indicate that neostriatal transplants are populated by the major output and internuncial neurons of the neostriatum.