[Abstract Title]. - Society for Neuroscience

whether the increased activation was the cause of MMs or the result of MMs. To clarify the
neural mechanism of MMs, we investigated kinematic and dynamic property of MMs using
acute primate model of M1 lesion induced by reversible inactivation of the hand area in M1 by
microinjection of muscimol, a GABAA receptor agonist (0.5-3κl). Two monkeys were trained to
retrieve a morsel of food from the tube positioned in the front with a free hand, while the other
hand was restricted. EMG activity was recorded from a total of 22 muscles of both hands. After
inactivation of the hand area of the right M1, movements of the left hand was partially impaired
when the monkey was required to reach for and grasp a small piece of food. MMs appeared on
the right hand when the monkey grasped a food piece and/or released it to the mouth with the left
hand. Mirror EMG activity was then observed in both flexor and extensor hand muscles. Peak
value of cross-correlogram between homologous muscles on both hands at time-zero lag
increased after inactivation the right M1, which indicated emergence of mirror activity in both
hands. Then, muscimol was injected into the hand area of the left M1. After inactivation of the
left M1, the peak of cross-correlogram disappeared. This reflected disappearance of the MMs
and mirror EMG activity. These results suggests that following the inactivation of the right M1,
the activity of the left M1 was increased and led to induction of the MM that appeared in the
right hand.
Disclosures: F. Tsuboi, None; Y. Nishimura, None; K. Saito, None; T. Isa, None.
Poster
272. Kinematics and EMG: Diseases
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 272.5/II4
Topic: D.12.b. Diseases
Support: Natural sciences and engineering research council of Canada
Fond de la recherche en santé du Québec
Canada foundation for innovation
Title: Amplitude of normal physiological tremor can be self-modulated
Authors: *B. CARIGNAN, J.-F. DANEAULT, D. BEAUDOIN, C. DUVAL;
UQAM, Montreal, QC, Canada
Abstract: INTRODUCTION: Normal physiological tremor (NPT) is a very small unconscious
movement, which has an amplitude of ~0.097mm. We recently showed that the amplitude of