TY - JOUR
T1 - Absence of linear correlation between fluctuations in area of simultaneous recorded monosynaptic responses and Hoffmann's reflexes in the rat
AU - Reyes, Celia
AU - Segura, Bertha
AU - Reza, Joaquina A.
AU - Pacheco, Maria Trinidad
AU - Lomelí, Joel
AU - Guadarrama, José Carlos
AU - Guevara, Rosalinda
AU - Jiménez, Ismael
N1 - Funding Information:
We would like to thank Mr. Alan Larsen for grammar corrections to the manuscript and Enrique Velázquez and Porfirio Reyes for their technical assistance in computer programming. Partially supported by Sistema Nacional de Investigadores, México.
PY - 2007/1/16
Y1 - 2007/1/16
N2 - In this study we analyze the possible relationship between fluctuations in area of monosynaptic reflex responses (MSR) and Hoffmann's reflex (H reflexes) in the plantar closed loop pathway of the anesthetized rat. These reflexes were evoked by low-frequency stimuli applied to the sciatic nerve or lateral plantar nerve and then concurrently recorded on the distal tibial nerve or lateral plantar nerve, respectively as well as the lateral plantar muscles in the foot of the anesthetized rat. From trial to trial, H reflexes showed higher variability in area than MSR, whether the latter was recorded in the distal tibial nerve (n = 8 experiments) or in the lateral plantar nerve (n = 5 experiments). No linear correlation was found between changes in area of concurrently evoked MSR and H reflexes (r(MSR-H,n=8) = 0.11 ± 0.03 and r(MSR-H,n=5) = 0.08 ± 0.09, respectively). These findings suggest that trial-to-trial fluctuations in area of H reflexes may involve interaction of several sources of variation, among others to MSR variability (due to pre-, and post-synaptic factors influencing the excitability of spinal motoneurons) in combination with those related to peripheral mechanisms, such as trial to trial activation of a different number of muscle fibers, either by the probabilistic transmitter release from neuromuscular junctions, by activation of motor units of variable size or to fluctuations in excitability of muscle fibers.
AB - In this study we analyze the possible relationship between fluctuations in area of monosynaptic reflex responses (MSR) and Hoffmann's reflex (H reflexes) in the plantar closed loop pathway of the anesthetized rat. These reflexes were evoked by low-frequency stimuli applied to the sciatic nerve or lateral plantar nerve and then concurrently recorded on the distal tibial nerve or lateral plantar nerve, respectively as well as the lateral plantar muscles in the foot of the anesthetized rat. From trial to trial, H reflexes showed higher variability in area than MSR, whether the latter was recorded in the distal tibial nerve (n = 8 experiments) or in the lateral plantar nerve (n = 5 experiments). No linear correlation was found between changes in area of concurrently evoked MSR and H reflexes (r(MSR-H,n=8) = 0.11 ± 0.03 and r(MSR-H,n=5) = 0.08 ± 0.09, respectively). These findings suggest that trial-to-trial fluctuations in area of H reflexes may involve interaction of several sources of variation, among others to MSR variability (due to pre-, and post-synaptic factors influencing the excitability of spinal motoneurons) in combination with those related to peripheral mechanisms, such as trial to trial activation of a different number of muscle fibers, either by the probabilistic transmitter release from neuromuscular junctions, by activation of motor units of variable size or to fluctuations in excitability of muscle fibers.
KW - EMG
KW - ENG
KW - Spinal reflexes
KW - Variability
UR - http://www.scopus.com/inward/record.url?scp=33751526950&partnerID=8YFLogxK
U2 - 10.1016/j.neulet.2006.10.038
DO - 10.1016/j.neulet.2006.10.038
M3 - Artículo
C2 - 17123729
AN - SCOPUS:33751526950
SN - 0304-3940
VL - 411
SP - 249
EP - 253
JO - Neuroscience Letters
JF - Neuroscience Letters
IS - 3
ER -