Shared Components of Rhythm Generation for Locomotion and Scratching Exist Prior to Motoneurons
Does the spinal cord use a single network to generate locomotor and scratching rhythms or two separate networks? Previous research showed that simultaneous swim and scratch stimulation (“dual stimulation”) in immobilized, spinal turtles evokes a single rhythm in hindlimb motor nerves with a frequenc...
Main Authors: | , |
---|---|
Format: | Article |
Language: | English |
Published: |
Frontiers Media S.A.
2017-08-01
|
Series: | Frontiers in Neural Circuits |
Subjects: | |
Online Access: | http://journal.frontiersin.org/article/10.3389/fncir.2017.00054/full |
id |
doaj-e76e8f6a96c94a039565bab5642cd96f |
---|---|
record_format |
Article |
spelling |
doaj-e76e8f6a96c94a039565bab5642cd96f2020-11-25T01:08:15ZengFrontiers Media S.A.Frontiers in Neural Circuits1662-51102017-08-011110.3389/fncir.2017.00054282982Shared Components of Rhythm Generation for Locomotion and Scratching Exist Prior to MotoneuronsZhao-Zhe Hao0Zhao-Zhe Hao1Ari Berkowitz2Ari Berkowitz3Department of Biology, University of Oklahoma, NormanOK, United StatesCellular and Behavioral Neurobiology Graduate Program, University of Oklahoma, NormanOK, United StatesDepartment of Biology, University of Oklahoma, NormanOK, United StatesCellular and Behavioral Neurobiology Graduate Program, University of Oklahoma, NormanOK, United StatesDoes the spinal cord use a single network to generate locomotor and scratching rhythms or two separate networks? Previous research showed that simultaneous swim and scratch stimulation (“dual stimulation”) in immobilized, spinal turtles evokes a single rhythm in hindlimb motor nerves with a frequency often greater than during swim stimulation alone or scratch stimulation alone. This suggests that the signals that trigger swimming and scratching converge and are integrated within the spinal cord. However, these results could not determine whether the integration occurs in motoneurons themselves or earlier, in spinal interneurons. Here, we recorded intracellularly from hindlimb motoneurons during dual stimulation. Motoneuron membrane potentials displayed regular oscillations at a higher frequency during dual stimulation than during swim or scratch stimulation alone. In contrast, arithmetic addition of the oscillations during swimming alone and scratching alone with various delays always generated irregular oscillations. Also, the standard deviation of the phase-normalized membrane potential during dual stimulation was similar to those during swimming or scratching alone. In contrast, the standard deviation was greater when pooling cycles of swimming alone and scratching alone for two of the three forms of scratching. This shows that dual stimulation generates a single rhythm prior to motoneurons. Thus, either swimming and scratching largely share a rhythm generator or the two rhythms are integrated into one rhythm by strong interactions among interneurons.http://journal.frontiersin.org/article/10.3389/fncir.2017.00054/fullcentral pattern generatorspinal cordbehavioral choicesynaptic inputmotoneuronturtle |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Zhao-Zhe Hao Zhao-Zhe Hao Ari Berkowitz Ari Berkowitz |
spellingShingle |
Zhao-Zhe Hao Zhao-Zhe Hao Ari Berkowitz Ari Berkowitz Shared Components of Rhythm Generation for Locomotion and Scratching Exist Prior to Motoneurons Frontiers in Neural Circuits central pattern generator spinal cord behavioral choice synaptic input motoneuron turtle |
author_facet |
Zhao-Zhe Hao Zhao-Zhe Hao Ari Berkowitz Ari Berkowitz |
author_sort |
Zhao-Zhe Hao |
title |
Shared Components of Rhythm Generation for Locomotion and Scratching Exist Prior to Motoneurons |
title_short |
Shared Components of Rhythm Generation for Locomotion and Scratching Exist Prior to Motoneurons |
title_full |
Shared Components of Rhythm Generation for Locomotion and Scratching Exist Prior to Motoneurons |
title_fullStr |
Shared Components of Rhythm Generation for Locomotion and Scratching Exist Prior to Motoneurons |
title_full_unstemmed |
Shared Components of Rhythm Generation for Locomotion and Scratching Exist Prior to Motoneurons |
title_sort |
shared components of rhythm generation for locomotion and scratching exist prior to motoneurons |
publisher |
Frontiers Media S.A. |
series |
Frontiers in Neural Circuits |
issn |
1662-5110 |
publishDate |
2017-08-01 |
description |
Does the spinal cord use a single network to generate locomotor and scratching rhythms or two separate networks? Previous research showed that simultaneous swim and scratch stimulation (“dual stimulation”) in immobilized, spinal turtles evokes a single rhythm in hindlimb motor nerves with a frequency often greater than during swim stimulation alone or scratch stimulation alone. This suggests that the signals that trigger swimming and scratching converge and are integrated within the spinal cord. However, these results could not determine whether the integration occurs in motoneurons themselves or earlier, in spinal interneurons. Here, we recorded intracellularly from hindlimb motoneurons during dual stimulation. Motoneuron membrane potentials displayed regular oscillations at a higher frequency during dual stimulation than during swim or scratch stimulation alone. In contrast, arithmetic addition of the oscillations during swimming alone and scratching alone with various delays always generated irregular oscillations. Also, the standard deviation of the phase-normalized membrane potential during dual stimulation was similar to those during swimming or scratching alone. In contrast, the standard deviation was greater when pooling cycles of swimming alone and scratching alone for two of the three forms of scratching. This shows that dual stimulation generates a single rhythm prior to motoneurons. Thus, either swimming and scratching largely share a rhythm generator or the two rhythms are integrated into one rhythm by strong interactions among interneurons. |
topic |
central pattern generator spinal cord behavioral choice synaptic input motoneuron turtle |
url |
http://journal.frontiersin.org/article/10.3389/fncir.2017.00054/full |
work_keys_str_mv |
AT zhaozhehao sharedcomponentsofrhythmgenerationforlocomotionandscratchingexistpriortomotoneurons AT zhaozhehao sharedcomponentsofrhythmgenerationforlocomotionandscratchingexistpriortomotoneurons AT ariberkowitz sharedcomponentsofrhythmgenerationforlocomotionandscratchingexistpriortomotoneurons AT ariberkowitz sharedcomponentsofrhythmgenerationforlocomotionandscratchingexistpriortomotoneurons |
_version_ |
1725183479404036096 |