Effects of climbing fiber destruction on large dendrite spines of Purkinje cells.
The number and freeze-fracture membrane organization of spines on Purkinje cell dendrites were studied in rats after destruction, by intraperitoneal injection of 3-acetyl-pyridine (3-AP), of the climbing fiber afferents to the cerebellum. The results obtained show that: (1) there is a 1.6 fold increase in the total number of dendritic spines in the 3-AP-treated animals as compared to controls, but no change in the total number of spine synaptic profiles; (2) the spines from main dendrites in both control and 3-AP-treated animals have more than 1,000 IMP/micron 2 of P-face membrane; and, (3) the spines formed on Purkinje cell dendrites in the absence of their presynaptic axons have the same P-face membrane organization (i.e. more than 1,000 IMP/micron 2) as spines normally innervated by afferent climbing fibers. These data suggest that each type of Purkinje cell spine has a specific P-face membrane organization which does not appear to be influenced by presynaptic terminals.
D000344:Afferent Pathways / Q000033:anatomy & histology; D000818:Animals; D002450:Cell Communication; D002531:Cerebellum / Q000033:anatomy & histology*; D003712:Dendrites / Q000648:ultrastructure*; D003714:Denervation; D005260:Female; D005614:Freeze Fracturing; D008526:Medulla Oblongata / Q000033:anatomy & histology; D008565:Membrane Proteins / Q000032:analysis; D008854:Microscopy, Electron; D009412:Nerve Fibers / Q000648:ultrastructure*; D009847:Olivary Nucleus / Q000033:anatomy & histology; D011689:Purkinje Cells / Q000648:ultrastructure*; D051381:Rats; D011919:Rats, Inbred Strains; D013570:Synaptic Membranes / Q000648:ultrastructure
D008565:Membrane Proteins