Long lasting structural changes in primary motor cortex after motor skill learning: a behavioural and stereological study

• Main Author: PAOLA MORALES
• Format: Article
• Language: English
• Published: BMC 2008-12-01
• Series: Biological Research
• Subjects: Motor cortex; plasticity; persistence of structural changes; aging; motor skill learning (skilled reaching task); stereology; rat
• Online Access: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602008000400005

Many motor skills, once acquired, are stored over a long time period, probably sustained by permanent neuronal changes. Thus, in this paper we have investigated with quantitative stereology the generation and persistence of neuronal density changes in primary motor cortex (MI) following motor skill learning (skilled reaching task). Rats were trained a lateralised reaching task during an "early" (22-31 days oíd) or "late" (362-371 days oíd) postnatal period. The trained and corresponding control rats were sacrificed at day 372, immediately after the behavioural testing. The "early" trained group preserved the learned skilled reaching task when tested at day 372, without requiring any additional training. The "late" trained group showed a similar capacity to that of the "early" trained group for learning the skilled reaching task. All trained animáis ("early" and "late" trained groups) showed a significant Ínter hemispheric decrease of neuronal density in the corresponding motor forelimb representation área of MI (cortical layers II-III)