The organization of the thalamostriatal projection from the lateral posterior thalamic nuclear complex (LP) in the pigmented rat.
We investigated the thalamostriatal projection of the rat using biotinylated dextran amine (BDA) and wheat-germ agglutinin horseradish peroxidase (WGA-HRP). To obtain the patch/matrix compartments of the striatum (ST), we used mu-opioid receptor (MOR) immunoreaction labeling. Thus, an MOR-positive 'patch' was indicated by a darkly stained spot, while the MOR-negative 'matrix' was displayed as a non-immunoreactive region. A small injection of BDA was made in a subregion of the lateral posterior thalamic nucleus (LP). The LP-ST fibers originated in all subregions of LP and terminated in the dorsocaudal portion of ST, where the corticostriatal fibers from the visual cortex terminate (Serizawa et al. 1994). These LP-ST fibers and terminals were concentrated in the MOR-negative matrix compartment. Electron microscopic observations showed that the LP-ST terminals made asymmetrical synaptic contacts mainly (70%, n = 30) with the dendritic spines of the presumptive ST-output neurons, and fewer (30%) contacted dendritic shafts. The present results provide anatomical support for the contention that ST-output spiny neurons of the matrix that project to the pars reticulata of the substantia nigra or globus pallidus, may be influenced directly by the LP-ST projection.
Funaki
S
S
Department of Neurobiology and Anatomy, Niigata University School of Medicine, Japan.
Meguro
R
R
Abe
H
H
Norita
M
M
D000818:Animals; D001370:Axonal Transport / Q000187:drug effects / Q000502:physiology; D001710:Biotin / Q000031:analogs & derivatives / Q000494:pharmacology; D003342:Corpus Striatum / Q000033:anatomy & histology*; D003911:Dextrans / Q000494:pharmacology; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology; D017729:Presynaptic Terminals / Q000648:ultrastructure; D051381:Rats; D020318:Rats, Long-Evans; D017450:Receptors, Opioid, mu / Q000032:analysis; D013238:Stereotaxic Techniques; D013787:Thalamic Nuclei / Q000033:anatomy & histology*; D013788:Thalamus / Q000033:anatomy & histology*; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate / Q000494:pharmacology
D003911:Dextrans; D017450:Receptors, Opioid, mu; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; C076397:biotinylated dextran amine; D001710:Biotin