Figure 5  .

Histogram showing size (average diameter) distributions of neurones in different age groups following ad libitum (AL) and restricted diet (RD) feeding in 24 month old rats. Note the rightward shift of neurone sizes at all ages after six months, indicating continued neurone growth in adult life. The frequency of neurones of 15-17.5 µm diameter is reduced in the 24 month AL group compared with the 24 month RD group, matching the average size of cholinergic neurones measured separately in neurones from 24 month RD rats (data not shown).