Catherine Morin

Learn More
1. A method to assess changes in presynaptic inhibition of I a afferent terminals in man is proposed. The soleus H reflex was facilitated by a heteronymous I a volley from quadriceps and the amount of reflex facilitation was used to estimate the size of the conditioning I a excitatory post-synaptic potential (e.p.s.p.). It is argued that the size of this(More)
Variations in the H-reflex of soleus (Sol), quadriceps (Q) and short head of biceps femoris (Bi) muscles in normal man were used to investigate the effect of volleys in low threshold cutaneous afferents from the ipsilateral limb on transmission of Ib effects from ankle and Q muscles to these different motoneurone (MN) pools. Stimulation of cutaneous(More)
Recurrent inhibition elicited by a conditioning H reflex is measured in normal man by the amount of inhibition of a test H reflex produced by motoneurones that have already given rise to the conditioning reflex. The recurrent inhibition of soleus motoneurones is lowered during a voluntary contraction of this muscle while it is enhanced during a voluntary(More)
Variations in the H-reflex of soleus, tibialis anterior, quadriceps and short head of biceps femoris muscles were studied in normal man, preceded by a conditioning stimulus applied to either gastrocnemius medialis, the inferior branch of soleus or the common peroneal nerve. The observed variations were evoked by low threshold afferents, had a very short(More)
A new method for estimating presynaptic inhibition of soleus (Sol) Ia fibres in man is introduced based on the assessment of the amount of facilitation produced by a preceding homonymous Ia volley onto a Sol monosynaptic reflex. It was found in animal experiments that a reduction of such Ia facilitation reflects the amount of presynaptic inhibition exerted(More)
Variations of presynaptic inhibition in heteronymous Ia fibres projecting to soleus motoneurones were studied during the first 250 ms of phasic voluntary isometric contractions of the antagonist tibialis anterior muscle in human subjects. During the first 60-80 ms of TA e.m.g activity, presynaptic inhibition was often more marked than at rest, but not in(More)
Variations of the soleus H-reflex were studied during voluntary isometric or anisometric contractions of the tibialis anterior in man. At the onset of isometric contractions there was a weak inhibition of the soleus H-reflex, which was not related to the force of the tibialis anterior contraction. 110 msec after the onset of the EMG activity, the inhibition(More)
The facilitating effect of the Jendrassik manoeuvre on monosynaptic reflexes in man has been studied by comparing H and T reflexes of the soleus and by blocking the effects of spindle activation by ischaemia of the leg. The Jendrassik manoeuvre equally enhances H and T reflexes provided that the test reflexes are small. The H reflex remains facilitated when(More)
A-ring fluorination of estradiol (ES) at position 2 or 4 decreases the rate of metabolism by blocking the formation of catechol estrogens, one of the major metabolic pathways of ES. We postulate that adding a 2- or 4-fluoro substituent to 16alpha-[18F]fluoroestradiol (FES), a positron emission tomography (PET) radiopharmaceutical used for estrogen receptor(More)
Facilitation of the spinal monosynaptic reflex by auditory stimulation has been demonstrated previously in animals and man. Analysis of the time course of audiospinal facilitation (ASF) in normal subjects is reported. The role of the cerebral cortex in the control of audiospinal facilitation was investigated in 32 patients with anatomically(More)