TY - JOUR
T1 - Dendritic regression dissociated from neuronal death but associated with partial deafferentation in aging rat supraoptic nucleus
AU - Flood, Dorothy G.
AU - Coleman, Paul D.
N1 - Funding Information:
This work was supported by NIH grants AG 01456, AG 01121, AG 03644, and AG 09016. The authors wish to thank Ms. Mary Balm, Ms. Thurma McDaniel, and Ms. Nancy Frambes for their technical assistance.
PY - 1993
Y1 - 1993
N2 - As neurons are lost in normal aging, the dendrites of surviving neighbor neurons may proliferate, regress, or remain unchanged. In the case of age-related dendritic regression, it has been difficult to distinguish whether the regression precedes neuronal death or whether it is a consequence of loss of afferent supply. The rat supraoptic nucleus (SON) represents a model system in which there is no age-related loss of neurons, but in which there is an age-related loss of afferents. The magnocellular neurosecretory neurons of the SON, that produce vasopressin and oxytocin for release in the posterior pituitary, were studied in male Fischer 344 rats at 3, 12, 20, 27, 30, and 32 months of age. Counts in Nissl-stained sections showed no neuronal loss with age, and confirmed similar findings in other strains of rat and in mouse and human. Nucleolar size increased between 3 and 12 months of age, due, in part, to nucleolar fusion, and was unchanged between 12 and 32 months of age, indicating maintenance of general cellular function in old age. Dendritic extent quantified in Golgi-stained tissue increased between 3 and 12 months of age, was stable between 12 and 20 months, and decreased between 20 and 27 months. We interpret the increase between 3 and 12 months as a late maturational change. Dendritic regression between 20 and 27 months was probably the result of deafferentation due to the preceding age-related loss of the noradrenergic input to the SON from the ventral medulla.
AB - As neurons are lost in normal aging, the dendrites of surviving neighbor neurons may proliferate, regress, or remain unchanged. In the case of age-related dendritic regression, it has been difficult to distinguish whether the regression precedes neuronal death or whether it is a consequence of loss of afferent supply. The rat supraoptic nucleus (SON) represents a model system in which there is no age-related loss of neurons, but in which there is an age-related loss of afferents. The magnocellular neurosecretory neurons of the SON, that produce vasopressin and oxytocin for release in the posterior pituitary, were studied in male Fischer 344 rats at 3, 12, 20, 27, 30, and 32 months of age. Counts in Nissl-stained sections showed no neuronal loss with age, and confirmed similar findings in other strains of rat and in mouse and human. Nucleolar size increased between 3 and 12 months of age, due, in part, to nucleolar fusion, and was unchanged between 12 and 32 months of age, indicating maintenance of general cellular function in old age. Dendritic extent quantified in Golgi-stained tissue increased between 3 and 12 months of age, was stable between 12 and 20 months, and decreased between 20 and 27 months. We interpret the increase between 3 and 12 months as a late maturational change. Dendritic regression between 20 and 27 months was probably the result of deafferentation due to the preceding age-related loss of the noradrenergic input to the SON from the ventral medulla.
KW - Aging
KW - Dendrites
KW - Fischer 344
KW - Golgi
KW - Hypothalamus
KW - Neuronal number
KW - Nucleoli
KW - Rat
KW - Supraoptic nucleus
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U2 - 10.1016/0197-4580(93)90042-A
DO - 10.1016/0197-4580(93)90042-A
M3 - Article
C2 - 7507575
AN - SCOPUS:0027130922
SN - 0197-4580
VL - 14
SP - 575
EP - 587
JO - Neurobiology of Aging
JF - Neurobiology of Aging
IS - 6
ER -