Lower Boundaries of Motoneuron Desynchronization via Renshaw Interneurons
نویسندگان
چکیده
Robert E. Druzinsky Dept. of Physiology Northwestern University Chicago, IT.. 60611 w. Zev Rymer Dept. of Physiology and Biomedical Engineering Northwestern University Chicago, IT.. 60611 Using a quasi-realistic model of the feedback inhibition ofmotoneurons (MNs) by Renshaw cells, we show that weak inhibition is sufficient to maximally desynchronize MNs, with negligible effects on total MN activity. MN synchrony can produce a 20 30 Hz peak in the force power spectrum, which may cause instability in feedback loops.
منابع مشابه
Decorrelating actions of Renshaw interneurons on the firing of spinal motoneurons within a motor nucleus: a simulation study.
A simulation of spinal motoneurons and Renshaw cells was constructed to examine possible functions of recurrent inhibition. Recurrent inhibitory feedback via Renshaw cells is known to be weak. In our model, consistent with this, motoneuron firing was only reduced by a few pulses per second. Our initial hypothesis was that Renshaw cells would suppress synchronous firings of motoneurons caused by...
متن کاملSpinal Sensorimotor Systems Part III:
So far as the signaling pathways to -motoneurons ( -MNs) are concerned, the motoneuron level (MNL) of the spinal cord neural network system is composed of five types of neurons: The -MNs, the Ia inhibitory interneurons (Ia-INs), the Ia/Ib non-reciprocal interneurons (Ib-INs), the group II ventral horn interneurons (IIVH-INs), and the Renshaw cells (RCs). Perhaps the easiest way to explain the -...
متن کاملCholinergic terminals in the ventral horn of adult rat and cat: evidence that glutamate is a cotransmitter at putative interneuron synapses but not at central synapses of motoneurons.
Until recently it was generally accepted that the only neurotransmitter to be released at central synapses of somatic motoneurons was acetylcholine. However, studies on young mice (P0-10) have provided pharmacological evidence indicating that glutamate may act as a cotransmitter with acetylcholine at synapses between motoneurons and Renshaw cells. We performed a series of anatomical experiments...
متن کاملModelling study of spinal generators structure; the role of alpha motoneurons, Renshaw cells and Ia interneurons in locomotion.
The properties of a model system composed of nets of motoneurons, Ia interneurons and Renshaw cells corresponding to the set of muscles driving one joint were analyzed from the point of view of their participation in locomotion control, i.e., generation of signals driving individual muscles. The model was constructed of neuron-like analog elements. The relations between the structure of the sys...
متن کاملIdentification of an interneuronal population that mediates recurrent inhibition of motoneurons in the developing chick spinal cord.
Studies on the development of synaptic specificity, embryonic activity, and neuronal specification in the spinal cord have all been limited by the absence of a functionally identified interneuron class (defined by its unique set of connections). Here, we identify an interneuron population in the embryonic chick spinal cord that appears to be the avian equivalent of the mammalian Renshaw cell (R...
متن کامل