title: Dying-back of Purkinje cell dendrites with synapse loss in aging rats.
abstract: Qualitative and quantitative changes were found in the cerebellar circuitry of old as compared to young rats. The old group had a reduced number of synapses (at least 30%), however, there was an increase in the size of remaining synaptic components (13.5% for spine head volume, 66% for bouton volume, and 17% for the area of synaptic contact zones). Furthermore, there were pronounced morphological changes in the older group appearing as: 1) prominent lipofuscin bodies in Purkinje cell somata, 2) numerous myelinated fibers in the lower part of the molecular layer, 3) tortuous Purkinje cell dendrites in a thinned molecular layer, and 4) abundant vacuolar profiles and membrane swirls in small and intermediate-sized dendrites. Our findings suggest that Purkinje cell dendrites are dying-back reducing the target field for granule cells and that remaining synaptic sites compensate by increasing synaptic contact area as well as the size of pre- and postsynaptic structures.
authors.affiliation: Departments of Otolaryngology and Physiology/Biophysics, New York University Medical Center, 550 First Avenue, New York, NY 10016, USA.
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.forename: D E
authors.initials: DE
authors.lastname: Hillman
mesh_terms: D000375:Aging / Q000473:pathology*; D000818:Animals; D001369:Axons / Q000648:ultrastructure; D064026:Calbindins; D003712:Dendrites / Q000737:chemistry / Q000648:ultrastructure*; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D005260:Female; D007150:Immunohistochemistry; D008062:Lipofuscin / Q000032:analysis; D009186:Myelin Sheath / Q000648:ultrastructure; D009419:Nerve Tissue Proteins / Q000032:analysis; D009473:Neuronal Plasticity; D011689:Purkinje Cells / Q000737:chemistry / Q000648:ultrastructure*; D051381:Rats; D011916:Rats, Inbred F344; D064030:S100 Calcium Binding Protein G / Q000032:analysis; D013569:Synapses / Q000648:ultrastructure*; D014617:Vacuoles / Q000648:ultrastructure
chemical_list: D064026:Calbindins; D008062:Lipofuscin; D009419:Nerve Tissue Proteins; D064030:S100 Calcium Binding Protein G