TABLE 2.
STRUCTURES THAT CHANGE WITH AGE: BUT THE CHANGES HAVE NOT BEEN SHOWN TO CORRELATE WITH COGNITIVE DECLINE
| Correlation with age | Correlation with Behavior | Source | |
|---|---|---|---|
| FOREBRAIN | |||
| Gray matter volume reduction (2.08%) | p=0.037 | No correlation | Wisco et al., 2008 |
| White matter volume reduction (11.53%) | p= 0.0003 | No correlation | Wisco et al., 2008 |
| CEREBRAL CORTEX OVERALL | |||
| Thickening of sup. temp. and cingulate cortices | p=0.01–0.05 | Not done | Koo et al., 2010 |
| Thinning of somatosensory and motor cortices | p<0.01 | Not done | Koo et al., 2010 |
| SENILE PLAQUES | |||
| Increased senile plaque burden | p=0.05–0.09 | No correlation |
Struble et al., 1985; Sloane et al., 1997 Heilbroner and Kemper, 1990 |
| LAYER I | |||
| Area 17: decrease in thickness | p<0.01 | No correlation | Peters et al., 2001 |
| Area 17: decreased density of synapses | p<0.01 | No correlation | Peters et al., 2001 |
| DENDRITIC AND SPINE CHANGES | |||
| Decrease in spine density on layer 3 long projecting neurons in Sup. Temp Gyrus (25%) | p<0.01 | Not done | Duan et al., 2003; Kabaso et al., 2009 |
| Decreased spine density on layer 3 locally projecting neurons in Area 46 (18%) | p<0.01 | Not done | Kabaso et al., 2009 |
| SYNAPSES | |||
| Area 46, Layer 5:Loss of asymmetric synapses (20%) | p=0.02 | No correlation | Peters et al., 2008a |
| Area 46, Layer 5:Loss of symmetric synapses(10%) | p=0.31 | No correlation | Peters et al., 2008a |
| Area 46, Layer 2/3 increased size of axosomatic terminals | p=0.02 | No correlation | Soghomonian et al., 2010 |
| Area 46, Layer 2/3: increased size of axodendritic terminals | p<0.0001 | No correlation | Soghomonian et al., 2010 |
| Dentate gyrus; outer molecular layer; loss of axodendritic synapses | no p value | not done | Tigges et al., 1995 |
| NERVE FIBER LOSS | |||
| Genu of corpus callosum (20%) | p<0.05 | No correlation | Bowley et al., 2010 |
| Cingulate bundle (20%) | p<0.005 | No correlation | Bowley et al., 2010 |
| Optic nerve (45%) | p<0.0001 | Not done | Sandell and Peters, 2001 |
| FREQUENCY OF ALTERED AXONS | |||
| Anterior commissure (0.4%) | p<0.01 | No correlation | Sandell and Peters, 2003 |
| Splenium of corpus callosum (0.1%) | No correlation | No correlation | Peters and Sethares. Unpublished |
| FREQUENCY OF ALTERED SHEATHS | |||
| Anterior commissure (5.4%) | p<0.001 | No correlation | Sandell and Peters, 2003 |
| Genu of corpus callosum (7.9%) | p=0.005–0.0001 | No correlation | Bowley et al., 2010 |
| FREQUENCY OF PARANODES | |||
| Area 17 (13%) | p<0.001 | No correlation | Peters and Sethares, 2003 |
| Splenium of corpus callosum (8%) | p<0.0001 | No correlation | Peters and Sethares. Unpublished |
| Genu of corpus callosum (9%) | p<0.0001 | No correlation | Bowley et al., 2010 |
| Anterior commissure (7.3%) | p<0.01 | No correlation | Sandell and Peters, 2003 |
| Fornix (7.2%) | p<0.0002 | No correlation | Peters et al., 2010 |
| Cingulate bundle (7%) | p<0.05 | No correlation | Bowley et al., 2010 |
| INCREASE IN THICKNESS OF MYELIN SHEATHS | |||
| Area 17 | p=0.001 | No correlation | Peters et al., 2001 |
| FREQUENCY OF NEUROGLIAL CELLS | |||
| Area 46: increase in oligodendrocytes (45%) | p=0.05–0.003 | No correlation | Peters and Sethares. Unpublished |
| Fornix: increase in oligodendrocytes (20%) | p=0.003 p<0.01 |
No correlation Not done |
Peters et al., 2010 Sandell and Peters, 2002 |
| CAPILLARIES | |||
| Thickening of basal lamina | p=0.01 | No correlation | Peters and Sethares. Unpublished |
| Splitting of basal lamina | p=0.004 | No correlation | Peters and Sethares. Unpublished |