Age dependence of primary motor cortex plasticity induced by paired associative stimulation.
OBJECTIVE
The increase of elderly population prompted growing research for the understanding of cerebral phenomena sustaining learning abilities, with inclusion of long-term potentiation (LTP)-like plasticity phenomena. Aim of the present study was to characterize LTP-like plasticity dependence on age and gender.


METHODS
A LTP-like primary motor cortex plasticity inducing a potentiation of the motor evoked potential (MEP) to focal transcranial magnetic stimulation as a consequence of a paired associative stimulation (PAS) was induced in a 50 healthy subject cohort, equally distributed for gender and age groups (25 young subjects, mean age+/-SD=29.8+/-4.5 years; elderly 61.1+/-4.1 years).


RESULTS
Resting motor thresholds' excitability level increased in the elderly group, the basal MEP did not depend on gender or age. The PAS-induced primary motor cortex (M1) plastic excitability modulation was similar in young females and males, while it decreased with age in females only.


CONCLUSIONS
A reduction of the PAS-induced M1 plasticity in females after menopause was documented, possibly due to an impairment of intracortical excitatory network activity.


CONCLUSIONS
A LTP-like plasticity dependence on age was found in female only, suggesting caution in interpreting behavioural studies on learning abilities in dependence on age.
Tecchio
F
F
ISTC-CNR, Franca Tecchio, Unità MEG, Fatebenefratelli Hospital, Isola Tiberina, 00186 Roma, Italy; Casa di Cura San Raffaele Cassino e IRCCS San Raffaele Pisana, Italy. Electronic address: franca.tecchio@istc.cnr.it.
Zappasodi
F
F
ISTC-CNR, Franca Tecchio, Unità MEG, Fatebenefratelli Hospital, Isola Tiberina, 00186 Roma, Italy; AFaR, Fatebenefratelli Hospital, Isola Tiberina, Roma, Italy.
Pasqualetti
P
P
AFaR, Fatebenefratelli Hospital, Isola Tiberina, Roma, Italy; Casa di Cura San Raffaele Cassino e IRCCS San Raffaele Pisana, Italy.
Gennaro
L De
L
Department of Psychology, University 'Sapienza', Roma, Italy.
Pellicciari
M C
MC
Cognitive Neuroscience Unit, IRCCS "Centro San Giovanni di Dio - FBF", Brescia, Italy.
Ercolani
M
M
AFaR, Fatebenefratelli Hospital, Isola Tiberina, Roma, Italy.
Squitti
R
R
AFaR, Fatebenefratelli Hospital, Isola Tiberina, Roma, Italy.
Rossini
P M
PM
Department of Neurology, 'Campus Bio-Medico' University, Roma, Italy; AFaR, Fatebenefratelli Hospital, Isola Tiberina, Roma, Italy; Cognitive Neuroscience Unit, IRCCS "Centro San Giovanni di Dio - FBF", Brescia, Italy.
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology / Q000528:radiation effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology* / Q000528:radiation effects; D050781:Transcranial Magnetic Stimulation