Choline acetyltransferase- and substance P-like immunoreactive elements in fetal striatal grafts in the rat: a correlated light and electron microscopic study.
Fetal striatal neurons were transplanted into the ibotenic acid-lesioned rat striatum. Three months after transplantation, the graft tissue was processed for choline acetyltransferase- and substance P-like immunoreactivity and was subsequently examined at the light and electron microscopic levels. The study demonstrated that choline acetyltransferase- and substance P-like-immunoreactive neurons were homogenously present throughout fetal striatal grafts, although in decreased numbers compared with those in the normal rat striatum. The majority of the choline acetyltransferase-immunoreactive neurons had fusiform, oval, or polygonal somata with somatic diameters greater than 20 microns and contained deeply invaginated nuclei surrounded by copious cytoplasm. In addition, choline acetyltransferase-immunoreactive neurons with somatic diameters between 10 and 20 microns were also demonstrated. The grafts' substance P-like-immunoreactive neurons, which had somatic diameters between 10 and 25 microns and had oval or polygonal perikarya, could be classified into two types based on their ultrastructural characteristics. Type I neurons contained an unindented nucleus which was surrounded by a thin rim or moderate amount of cytoplasm, whereas Type II immunoreactive neurons contained an indented nucleus which was surrounded by copious cytoplasm. Choline acetyltransferase- and substance P-like-immunoreactive dendrites in the grafts' neuropil were contacted by multiple unlabeled axon terminals. In addition, choline acetyltransferase- and substance P-like-immunoreactive axon terminals forming symmetric contacts with unlabeled dendrites were present within the graft. The study demonstrated that many of the neuroanatomical features of choline acetyltransferase- and substance P-like-immunoreactive elements found in the normal rat striatum are present in mature fetal striatal grafts.
Helm
G A
GA
Department of Neurological Surgery, University of Virginia Health Sciences Center, Charlottesville 22908.
Palmer
P E
PE
Bennett
J P
JP
D000818:Animals; D001369:Axons / Q000201:enzymology; D016380:Brain Tissue Transplantation / Q000502:physiology*; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D003342:Corpus Striatum / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure; D003712:Dendrites / Q000201:enzymology; D005260:Female; D016332:Fetal Tissue Transplantation / Q000502:physiology*; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009411:Nerve Endings / Q000201:enzymology; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000276:immunology / Q000378:metabolism*
D013373:Substance P; D002795:Choline O-Acetyltransferase