Works SJ, Wellman CL (2001) Differential dendritic atrophy in frontal cortex after cholinergic lesion in young adult and aged rats. Neuroscience 2001 Abstracts 101.17. Society for Neuroscience, San Diego, CA.
Summary: Previously, we demonstrated that plasticity of frontal cortex is altered in aging rats: three months after surgery, ibotenic acid lesions of the nucleus basalis magnocellularis (NBM) produce larger declines in dendritic morphology in frontal cortex of aged rats relative to young adults. To determine whether the differential effect of the lesion was due specifically to loss of cholinergic input from the NBM, we assessed dendritic morphology in frontal cortex after cholinergic depletion in young adult and aged male rats. Rats received unilateral lesions of the NBM using 192 IgG-saporin, and sham lesions of the contralateral NBM. Two weeks after surgery, brains were stained using a Golgi-Cox procedure. Pyramidal neurons in lamina II-III of frontal cortex were drawn and dendritic morphology was quantified in three dimensions. In young adults, lesions did not alter overall branch number or length. However, in aged rats, lesions decreased basilar dendritic number and length, by 17% and 25% respectively. Furthermore, young adults demonstrated a lesion-induced redistribution of basilar dendrites: dendritic material proximal to the soma was decreased 15%, while distal dendritic material was increased as much as threefold relative to the sham-lesioned hemisphere. Alternatively, lesions in aged rats decreased the amount of distal dendritic material by 25%. Thus, the dendritic atrophy resulting from NBM lesions in aged rats occurs within two weeks after lesion, and results specifically from loss of cholinergic innervation.
Related Products: 192-IgG-SAP (Cat. #IT-01)