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Spontaneous movements: Effect of denervation and relation to the adaptation of nociceptive withdrawal reflexes in the rat.

Waldenström Ellervik, Alexandra LU ; Christensson, Maria LU and Schouenborg, Jens LU (2009) In Physiology & Behavior 98. p.532-536
Abstract
Spontaneous movements are a ubiquitous phenomenon during development. Recently, we demonstrated that these movements play a key role in the functional adaptation of spinal reflex circuits. Here, we analyse the role of afferent input in the generation of spontaneous movements and characterize the occurrence of different types of spontaneous movements and their relation to the functional adaptation of the nociceptive withdrawal reflexes (NWR) up to postnatal day 22 (P22). Noxious thermal stimulation was used to evoke reflex responses in awake rats. Spontaneous tail movements occurring during active sleep were counted during the first three postnatal weeks and classified into two major classes: simple movements (unidirectional) and complex... (More)
Spontaneous movements are a ubiquitous phenomenon during development. Recently, we demonstrated that these movements play a key role in the functional adaptation of spinal reflex circuits. Here, we analyse the role of afferent input in the generation of spontaneous movements and characterize the occurrence of different types of spontaneous movements and their relation to the functional adaptation of the nociceptive withdrawal reflexes (NWR) up to postnatal day 22 (P22). Noxious thermal stimulation was used to evoke reflex responses in awake rats. Spontaneous tail movements occurring during active sleep were counted during the first three postnatal weeks and classified into two major classes: simple movements (unidirectional) and complex twitches (bi-directional and oscillating). All spinal nerves caudal to L2 were cut at P12 to study the effect of deafferentation on spontaneous movements. The number of simple movements and complex twitches in the deafferented animals did not differ as compared to control animals. The adaptation of tail NWR occurred during the period P7-P22. Spontaneous tail movements occurred relatively frequently and overlapped in time the adaptation of NWR. Notably, the relative number of simple movements increased in parallel with the functional adaptation of the NWR, suggesting a role of simple twitches in NWR adaptation. The present findings indicate that the spontaneous movements studied are driven by intrinsic mechanisms in the CNS and suggest that sensory feedback does not influence the spontaneous movement patterns. Moreover, the NWR adaptation appears to be related to a qualitative change in spontaneous movements caused by maturation in spinal reflex circuit connections. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physiology & Behavior
volume
98
pages
532 - 536
publisher
Elsevier
external identifiers
  • wos:000272518200003
  • pmid:19715712
  • scopus:71549121323
ISSN
1873-507X
DOI
10.1016/j.physbeh.2009.08.009
language
English
LU publication?
yes
id
6c369537-3ed4-4f87-8970-bb265880301b (old id 1484021)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/19715712?dopt=Abstract
date added to LUP
2009-10-05 15:44:30
date last changed
2017-01-01 07:48:44
@article{6c369537-3ed4-4f87-8970-bb265880301b,
  abstract     = {Spontaneous movements are a ubiquitous phenomenon during development. Recently, we demonstrated that these movements play a key role in the functional adaptation of spinal reflex circuits. Here, we analyse the role of afferent input in the generation of spontaneous movements and characterize the occurrence of different types of spontaneous movements and their relation to the functional adaptation of the nociceptive withdrawal reflexes (NWR) up to postnatal day 22 (P22). Noxious thermal stimulation was used to evoke reflex responses in awake rats. Spontaneous tail movements occurring during active sleep were counted during the first three postnatal weeks and classified into two major classes: simple movements (unidirectional) and complex twitches (bi-directional and oscillating). All spinal nerves caudal to L2 were cut at P12 to study the effect of deafferentation on spontaneous movements. The number of simple movements and complex twitches in the deafferented animals did not differ as compared to control animals. The adaptation of tail NWR occurred during the period P7-P22. Spontaneous tail movements occurred relatively frequently and overlapped in time the adaptation of NWR. Notably, the relative number of simple movements increased in parallel with the functional adaptation of the NWR, suggesting a role of simple twitches in NWR adaptation. The present findings indicate that the spontaneous movements studied are driven by intrinsic mechanisms in the CNS and suggest that sensory feedback does not influence the spontaneous movement patterns. Moreover, the NWR adaptation appears to be related to a qualitative change in spontaneous movements caused by maturation in spinal reflex circuit connections.},
  author       = {Waldenström Ellervik, Alexandra and Christensson, Maria and Schouenborg, Jens},
  issn         = {1873-507X},
  language     = {eng},
  pages        = {532--536},
  publisher    = {Elsevier},
  series       = {Physiology & Behavior},
  title        = {Spontaneous movements: Effect of denervation and relation to the adaptation of nociceptive withdrawal reflexes in the rat.},
  url          = {http://dx.doi.org/10.1016/j.physbeh.2009.08.009},
  volume       = {98},
  year         = {2009},
}