2017
DOI: 10.1002/cne.24244
|View full text |Cite
|
Sign up to set email alerts
|

VGLUT1 synapses and P‐boutons on regenerating motoneurons after nerve crush

Abstract: Stretch-sensitive Ia afferent monosynaptic connections with motoneurons form the stretch reflex circuit. After nerve transection, Ia afferent synapses and stretch reflexes are permanently lost, even after regeneration and reinnervation of muscle by motor and sensory afferents is completed in the periphery. This loss greatly affects full recovery of motor function. However, after nerve crush, reflex muscle forces during stretch do recover after muscle reinnervation and reportedly exceed 140% baseline values. Th… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
1
1
1

Citation Types

5
18
1

Year Published

2018
2018
2024
2024

Publication Types

Select...
7
1

Relationship

3
5

Authors

Journals

citations
Cited by 19 publications
(24 citation statements)
references
References 56 publications
(111 reference statements)
5
18
1
Order By: Relevance
“…After nerve transection at the same location EPSP amplitudes from injured and regenerated Ia afferents onto heteronymous uninjured motoneurons recovered to around 50% of their original size (Mendell et al, 1995) while homonymous Ia EPSPs recovered much less in injury models affecting both Ia afferents and motoneurons (Eccles et al, 1959). These results agree with the good recovery of VGLUT1(Ia/II) synapses after nerve crush in rats (Schultz et al, 2017) compared to the lack of recovery when transecting the same nerve (Alvarez et al, 2011). Interestingly, recovered VGLUT1 (Ia/II) synapses following nerve crush displayed reduced presynaptic GABAergic P-boutons (Schultz et al, 2017), suggesting decreased presynaptic inhibition.…”
Section: Proprioceptive Inputs Axotomized In the Peripheral Nerve Undsupporting
confidence: 78%
See 1 more Smart Citation
“…After nerve transection at the same location EPSP amplitudes from injured and regenerated Ia afferents onto heteronymous uninjured motoneurons recovered to around 50% of their original size (Mendell et al, 1995) while homonymous Ia EPSPs recovered much less in injury models affecting both Ia afferents and motoneurons (Eccles et al, 1959). These results agree with the good recovery of VGLUT1(Ia/II) synapses after nerve crush in rats (Schultz et al, 2017) compared to the lack of recovery when transecting the same nerve (Alvarez et al, 2011). Interestingly, recovered VGLUT1 (Ia/II) synapses following nerve crush displayed reduced presynaptic GABAergic P-boutons (Schultz et al, 2017), suggesting decreased presynaptic inhibition.…”
Section: Proprioceptive Inputs Axotomized In the Peripheral Nerve Undsupporting
confidence: 78%
“…A major problem was the lack of anatomical analyses of Ia synapses after nerve injuries. These did not occur until recently (Alvarez et al, 2010(Alvarez et al, , 2011Rotterman et al, 2014;Schultz et al, 2017) facilitated by the discovery of VGLUT1 as a marker of proprioceptive synapses in the ventral horn (Todd et al, 2003;Alvarez et al, 2004). VGLUT1 synapses in lamina IX and on motoneurons, are mostly Ia synapses, but a minority might also originate from type II afferents (Alvarez et al, 2011;Vincent et al, 2017).…”
Section: Proprioceptive Inputs Axotomized In the Peripheral Nerve Undmentioning
confidence: 99%
“…On the other hand, deletion of Ia/II inputs might reduce connectivity incongruences between proprioceptors and MNs inside the spinal cord after both sensory and motor axons regenerate in the periphery. Different types of nerve injuries result in axon regeneration with variable success on targeting the original muscles, which correlates with more or less loss of Ia afferent synapses (Schultz et al, 2017). CCR2 cell entry similarly fluctuates with injury severity.…”
Section: Discussionmentioning
confidence: 99%
“…The number of VGLUT1 terminals per cell body was obtained and their density calculated by dividing the number of VGLUT1 contacts by the total cell body surface (per 100 m 2 ). VGLUT1 contacts on dendrites were estimated as linear densities by dividing the number of VGLUT1 terminals by total dendritic length of the traced dendrites (per 100 m) Schultz et al, 2017). Sholl analysis was used to examine VGLUT1 distributions in dendrite segments at 25 m bins of incremental radial distance from the center of the cell body.…”
Section: Methodsmentioning
confidence: 99%
“…Synaptic terminals are removed from cell bodies and dendrites of motoneurons by activated microglial and astroglial cells [ 1 6 ]. The overall posttraumatic loss is reversed to a large extent if muscles become reinnervated [ 3 , 6 , 7 ], but restoration of some synaptic inputs is incomplete [ 8 11 ]. Such deficits, for example, in cholinergic and glutamatergic innervation, may contribute to functional deficits after muscle reinnervation as they are well correlated with functional performance after long-term reinnervation [ 9 , 12 ].…”
Section: Introductionmentioning
confidence: 99%