Inhibitory inputs to four types of spinocerebellar tract neurons in the cat spinal cord

Shrestha, Sony; Bannatyne, B. Anne; Jankowska, E.; Hammar, Ingela; Nilsson, Elin; Maxwell, David

doi:10.1016/j.neuroscience.2012.09.015

Cited by 13 publications

(18 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…SBCs are innervated by a massive (approximately 5000) number of excitatory synaptic inputs from the RST and a comparable number of synaptic inputs from inhibitory interneurons [7], [8]. At the population level, these synaptic inputs can generate a total depolarization of up to 5 mV and a total hyperpolarization of about 7 mV when activated synchronously, using electrical stimulation of the descending tracts or afferent nerves [7], [8], [11], [38], [39].…”

Section: Resultsmentioning

confidence: 99%

“…At the population level, these synaptic inputs can generate a total depolarization of up to 5 mV and a total hyperpolarization of about 7 mV when activated synchronously, using electrical stimulation of the descending tracts or afferent nerves [7], [8], [11], [38], [39]. It follows, similar to the magnitude of synaptic weights in other synaptic junctions of the cat spinal cord [40], that the responses of the individual synaptic connections are likely to amount to only a few µVs in amplitude in SBCs.…”

Section: Resultsmentioning

confidence: 99%

“…It follows, similar to the magnitude of synaptic weights in other synaptic junctions of the cat spinal cord [40], that the responses of the individual synaptic connections are likely to amount to only a few µVs in amplitude in SBCs. On the other hand, since the SBCs receive so many RST synapses and inhibitory synapses from interneurons activated by Ib afferents, concerted activation of these inputs will be translated to relatively massive excitatory and inhibitory modulations of the intracellular potential (shown for VSCT neurons under fictive locomotion [9]), which are much slower than the responses obtained by synchronous fiber activation obtained on tract stimulation and nerve shock stimulation [7], [8]. The amplitude of these intracellular membrane potential changes should be related to the average firing rate of the neurons that converge onto the individual SBC.…”

Section: Resultsmentioning

confidence: 99%

“…SBCs receive a massive excitatory input from the reticulospinal tract (RST), representing a motor command, and powerful inhibition from Ib interneurons, representing a main sensory feedback to the SBCs [6]–[8]. Given the strong input from the RST, SBCs are likely to participate in the control of locomotion, similar to other cells of the VSCT [9], [10].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Simulating Spinal Border Cells and Cerebellar Granule Cells under Locomotion – A Case Study of Spinocerebellar Information Processing

et al. 2014

View full text Add to dashboard Cite

The spinocerebellar systems are essential for the brain in the performance of coordinated movements, but our knowledge about the spinocerebellar interactions is very limited. Recently, several crucial pieces of information have been acquired for the spinal border cell (SBC) component of the ventral spinocerebellar tract (VSCT), as well as the effects of SBC mossy fiber activation in granule cells of the cerebellar cortex. SBCs receive monosynaptic input from the reticulospinal tract (RST), which is an important driving system under locomotion, and disynaptic inhibition from Ib muscle afferents. The patterns of activity of RST neurons and Ib afferents under locomotion are known. The activity of VSCT neurons under fictive locomotion, i.e. without sensory feedback, is also known, but there is little information on how these neurons behave under actual locomotion and for cerebellar granule cells receiving SBC input this is completely unknown. But the available information makes it possible to simulate the interactions between the spinal and cerebellar neuronal circuitries with a relatively large set of biological constraints. Using a model of the various neuronal elements and the network they compose, we simulated the modulation of the SBCs and their target granule cells under locomotion and hence generated testable predictions of their general pattern of modulation under this condition. This particular system offers a unique opportunity to simulate these interactions with a limited number of assumptions, which helps making the model biologically plausible. Similar principles of information processing may be expected to apply to all spinocerebellar systems.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Simulating Spinal Border Cells and Cerebellar Granule Cells under Locomotion – A Case Study of Spinocerebellar Information Processing

et al. 2014

View full text Add to dashboard Cite

show abstract

“…(A) A cross-section of the L4 segment (from Shrestha et al, 2012a) indicating the two alternative orientation of the electrode tracks and the depths at which the SBCs were found. (B) Example of SBC extracellular unit (*) antidromically activated from sublobule C1 in the cerebellum.…”

Section: Resultsmentioning

confidence: 99%

Cerebellar cortical neuron responses evoked from the spinal border cell tract

Geborek

Spanne

Bengtsson

et al. 2013

Front. Neural Circuits

View full text Add to dashboard Cite

Spinocerebellar systems are likely to be crucial for cerebellar hallmark functions such as coordination. However, in terms of cerebellar functional analyses, these are perhaps among the least explored systems. The aim of the present study is to achieve activation of a single component of the spinocerebellar systems and to explore to what extent it can influence the spike output of granule cells, Golgi cells, molecular layer (ML) interneurons (stellate and basket cells) and Purkinje cells (PCs). For this purpose, we took advantage of a unique arrangement discovered in neuroanatomical studies, in which the spinal border cell (SBC) component of the ventral spinocerebellar system was found to be the only spinocerebellar tract which ascends in the contralateral lateral funiculus (coLF) and have terminations in sublobulus C1 of the paramedian lobule in the posterior cerebellum. Using electrical stimulation of this tract, we find a subset of the cerebellar cortical neurons in this region to be moderately or powerfully activated. For example, some of our granule cells displayed high intensity responses whereas the majority of the granule cells displayed no response at all. The finding that more than half of the PCs were activated by stimulation of the SBC tract indicated that this system is capable of directly influencing cerebellar cortical output. The implications of these findings for the view of the integrative functions of the cerebellar cortex are discussed.

show abstract

Control of Mammalian Locomotion by Somatosensory Feedback

Frigon

Akay

Prilutsky

2021

Comprehensive Physiology

View full text Add to dashboard Cite

When animals walk overground, mechanical stimuli activate various receptors located in muscles, joints, and skin. Afferents from these mechanoreceptors project to neuronal networks controlling locomotion in the spinal cord and brain. The dynamic interactions between the control systems at different levels of the neuraxis ensure that locomotion adjusts to its environment and meets task demands. In this article, we describe and discuss the essential contribution of somatosensory feedback to locomotion. We start with a discussion of how biomechanical properties of the body affect somatosensory feedback. We follow with the different types of mechanoreceptors and somatosensory afferents and their activity during locomotion. We then describe central projections to locomotor networks and the modulation of somatosensory feedback during locomotion and its mechanisms. We then discuss experimental approaches and animal models used to investigate the control of locomotion by somatosensory feedback before providing an overview of the different functional roles of somatosensory feedback for locomotion. Lastly, we briefly describe the role of somatosensory feedback in the recovery of locomotion after neurological injury. We highlight the fact that somatosensory feedback is an essential component of a highly integrated system for locomotor control.

show abstract

Inhibitory inputs to four types of spinocerebellar tract neurons in the cat spinal cord

Cited by 13 publications

References 66 publications

Simulating Spinal Border Cells and Cerebellar Granule Cells under Locomotion – A Case Study of Spinocerebellar Information Processing

Simulating Spinal Border Cells and Cerebellar Granule Cells under Locomotion – A Case Study of Spinocerebellar Information Processing

Cerebellar cortical neuron responses evoked from the spinal border cell tract

Control of Mammalian Locomotion by Somatosensory Feedback

Contact Info

Product

Resources

About