Localisation of parvalbumin-immunoreactive structures in primate caudate-putamen.
To investigate the morphology, distribution, and connections of parvalbumin-containing neurones in the caudate-putamen of primates, perfuse-fixed sections were stained to reveal parvalbumin immunoreactivity. In agreement with previous observations, the caudate-putamen was rich in parvalbumin-positive neurones and neuropil. The neuropil staining was uneven such that the dense background staining was interspersed with zones of relatively weak staining. The distribution corresponded to the striosome/matrix system as defined by substance P or met-enkephalin immunostaining in adjacent sections. Because parvalbumin-positive neurones are present in regions known to project to the caudate-putamen and the majority of parvalbumin-positive terminals in the matrix formed asymmetric synapses, it is concluded that the uneven staining is probably due to afferents of the neostriatum. The morphology of the parvalbumin-immunoreactive neurones varied between the striosomes and matrix; those in the matrix were smaller and possessed dendritic arborisations that were relatively uniform, whereas those in the striosomes were generally more extensively stained and possessed a greater variation in their dendritic branching patterns. The dendrites frequently crossed the boundary between the striosomes and matrix. A population of giant parvalbumin-immunoreactive neurones was also observed in the putamen. Electron microscopic analysis revealed that, in addition to terminals forming asymmetric synapses, a smaller population formed symmetric synaptic specialisations and are presumed to be derived from the local parvalbumin-immunoreactive neurones. Terminals of the latter group formed synapses with medium-sized spiny neurones. Because parvalbumin-positive neurones receive input from the cortex, they may transmit cortical information to spiny neurones.
Bennett
B D
BD
MRC Anatomical Neuropharmacology Unit, Oxford, United Kingdom.
Bolam
J P
JP
D000818:Animals; D002421:Caudate Nucleus / Q000737:chemistry* / Q000648:ultrastructure; D002522:Chlorocebus aethiops / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D008252:Macaca fascicularis / Q000378:metabolism*; D008854:Microscopy, Electron; D010320:Parvalbumins / Q000032:analysis*; D011699:Putamen / Q000737:chemistry* / Q000648:ultrastructure
D010320:Parvalbumins