Table 1.
Summary of variables that are known to change with age in Area 46 of the rhesus monkey. DNMs: delayed non-making-to-sample task: DRST: delayed recognition span task: CII: Cognitive Impairment Index.
| Direction of Change |
Task | Correlation P | Citation | |
|---|---|---|---|---|
|
Variables that are known to be unchanged with age in A46 |
||||
| Number of Neurons | na | na | na | Smith et al. 2004 |
| Volume(assessed with neuroanatomical methods) | na | na | na | O'Donnell et al. 1999 |
| Layer 5 pyramidal Cell-action potential frequency | na | na | na | Luebke & Chang, 2007 |
| Layer 5 pyramidal Cell-slow AHP amplitude | na | na | na | Luebke et al.,(submitted) |
|
Variables that change with age in A46 not tested for correlation with behavior |
||||
| Layer 3 pyramidal Cell-density of dendritic spines | Decreased | na | na | Duan et al, 2003 |
| Layer 3 pyramidal Cell-frequency of glutamatergic EPSCs | Decreased | na | na | Luebke et al. 2004 |
| Layer 3 pyramidal Cell-frequency of GABAergic IPSCs | Increased | na | na | Luebke et al. 2004 |
| Dopamine levels | Decreased | na | na | Goldman-Rakic and Brown, 1981 Wenk et al.,1989 |
| NE receptors | Decreased | na | na | Moore et al.,2005 |
| 5-HT receptors | Decreased | na | na | Goldman-Rakic, and Brown, 1981 Wenk et al.,1989; Bigham, and Lidow, 1995 |
| Chat, MI receptors | ?/Decreased | na | na | Vannucchi, and Goldman-Rakic, 1991 |
|
Variables that change with age in A46 and do NOT correlate with behavior |
||||
| Number of senile plaques | Increased | CII | na | Sloane et al.,1997 |
| Number of oligodendrocytes | Increased | CII | na | Peters et al. (unpublished) |
| Number of synapses in Layer 5/6 | Decreased | CII | na | Peters et al.,2008 |
|
Variables that change with age in A46 and correlate with behavior |
||||
| Gray matter volumes (assessed with MBI) | Decreased | DRST best DNMS |
p<0.008 na |
Alexander et al.,2008 |
| “Strength” of microcolumns | Decreased | CII | p<0.01 | Cruz et al.,2004 |
| Thickness of Layer 1 | Decreased | DNMS(2') | p<0.03 | Peters et al., 1998 |
| Number of synapses (total) in Layer 1 | Decreased | CII | p<0.05 | Peters et al.,1998 |
| Number of asymmetric synapses in Layer 2/3 | Decreased | CII | p<0.008 | Peters et al.,2008 |
| Number of symmetric synapses in Layer 2/3 | Decreased | CII | p<0.08 | Peters et al.,2008 |
| Number of abnormal myelin sheaths | Increased | CII | p<0.001 | Peters et al.,2002 |
| Number of paranodes | Increased | CII | p<0.01 | Peters and Sethares,2003 |
| Layer 2/3 pyramidal cell-slow AHP amplitude | Increased | CII,DNMS,DRST | p<0.03 | Luebke et al.,(submitted) |
| Layer 2/3 pyramidal cell-action potential frequency | Increased | CII, DRST, DNMS | p<0.02 | chang et al, 2005 |