The Experts below are selected from a list of 24 Experts worldwide ranked by ideXlab platform

Shelly A. Mcerlane - One of the best experts on this subject based on the ideXlab platform.

  • spontaneous spike activity of Spinoreticular Tract neurons during sleep and wakefulness
    2001
    Co-Authors: Peter J. Soja, Niwat Taepavarapruk, Walton Pang, Shelly A. Mcerlane
    Abstract:

    Sleep mentation studies infer that pain sensation in humans may be reduced during active REM sleep. However, to provide a mechanistic explanation for this phenomenon, few, if any neurophysiological studies have been performed at the lumbar level from neurons comprising classical pain pathways during sleep and wakefulness. The Spinoreticular Tract is one such classical pathway that has been implicated in the rostral transmission of nociceptive information. The present study was performed to determine if the activity of Spinoreticular Tract (SRT) neurons is dependent upon behavioral state. Accordingly, extracellular recording techniques were used to monitor the activity of identified SRT neurons in unanesthetized chronic cats during sleep and wakefulness. The ongoing spike activity of SRT neurons was found to be relatively uniform when the states of quiet wakefulness and quiet sleep were compared. However, during active sleep, the majority of the SRT neurons sampled underwent a sustained reduction in spike activity. Marked facilitation of SRT cell activity occurred in a few instances. These data provide the first unitary evidence supporting earlier evoked potential, psychophysical and clinical studies that ascending sensory information in a classical pain pathway is regulated in a state-dependent fashion.

  • On the reduction of spontaneous and glutamate-driven spinocerebellar and Spinoreticular Tract neuronal activity during active sleep.
    2001
    Co-Authors: Peter J. Soja, Niwat Taepavarapruk, B E Cairns, Walton Pang, Shelly A. Mcerlane
    Abstract:

    AbsTract The present study was performed to provide evidence that dynamic neural processes underlie the reduction in dorsal spinocerebellar Tract and Spinoreticular Tract neuron activity that occurs during active sleep. To ascertain the effect of local inhibition on the spontaneous and glutamate-evoked spike discharge of sensory Tract neurons, preliminary control tests were performed during the state of quiet wakefulness, where GABA or glycine was co-administered in a sustained fashion during pulsatile release of glutamate to dorsal spinocerebellar Tract ( n =3) or Spinoreticular Tract ( n =2) neurons. Co-administration of GABA or glycine also resulted in a significant marked suppression of spontaneous spike activity and glutamate-evoked responses of these cells. Extracellular recording experiments combined with juxtacellular application of glutamate were then performed on 20 antidromically identified dorsal spinocerebellar Tract and Spinoreticular Tract neurons in the chronic intact cat as a function of sleep and wakefulness. The glutamate-evoked activity of a group of 10 sensory Tract neurons (seven dorsal spinocerebellar Tract, three Spinoreticular Tract), which exhibited a significant decrease in their spontaneous spike activity during active sleep, was examined. Glutamate-evoked activity in these cells was significantly attenuated during active sleep compared with wakefulness. In contrast, the glutamate-evoked activity of a second group of eight sensory Tract neurons (four dorsal spinocerebellar Tract, four Spinoreticular Tract), which exhibited a significant increase in their spontaneous spike activity during active sleep, was not significantly altered in a state-dependent manner. These data indicate that, during natural active sleep, a dynamic neural process is engaged onto certain dorsal spinocerebellar Tract and Spinoreticular Tract neurons, which in turn dampens sensory throughput to higher brain centers.

D J Maxwell - One of the best experts on this subject based on the ideXlab platform.

  • the spino bulbar cerebellar pathway organization and neurochemical properties of spinal cells that project to the lateral reticular nucleus in the rat
    2015
    Co-Authors: Zilli Huma, D J Maxwell
    Abstract:

    In addition to classical spinocerebellar pathways, the cerebellum receives information from the spinal cord indirectly via spino-bulbar-cerebellar systems. One of the structures in this pathway is the lateral reticular nucleus (LRt). We performed series of experiments to investigate the organization and neurotransmitter content of Spinoreticular Tract (SRT) neurons in the lumbar spinal cord that project to the LRt. Three rats received injections of the b subunit of Cholera toxin (CTb) or Fluorogold (FG) within the left and right LRt. The majority of SRT cells (56–61%) were found within the contralateral medial intermediate gray matter where small numbers (7–10%) of double-labeled cells were also present on both sides of the cord. Six rats received unilateral spinal injections of CTb to label spinal projections to the LRt. Injections of FG were made also into the anterior lobe of the cerebellum to label LRt pre-cerebellar neurons. Terminals were found mainly ipsilateral to spinal injection sites within the central and ventrolateral regions of the LRt. Immunocytochemical analysis of SRT terminals revealed that the majority (75%) were contained vesicular glutamate transporter 2 but a minority (20%) contained the vesicular GABA transporter. The inhibitory subpopulation was found to be GABAergic, glycinergic, or contained both transmitters. Inhibitory and excitatory terminals were present within overlapping regions of the nucleus. Most CTb terminals contacting LRt pre-cerebellar neurons were excitatory (80%) whereas a minority were inhibitory and most cells (88%) received contacts from both inhibitory and excitatory terminals. This study shows that SRT axons in the LRt have the capacity to exert direct excitatory and inhibitory actions on LRt pre-cerebellar neurons. Thus spinal cord input has the capacity to facilitate or depress the activity of individual LRt cells which in turn adjust activity in the cerebellum to produce coordinated motor behaviors.

  • The spino-bulbar-cerebellar pathway: organisation and neurochemical properties of spinal cells that project to the lateral reticular nucleus in the rat.
    2015
    Co-Authors: Zilli Ehuma, D J Maxwell
    Abstract:

    In addition to classical spinocerebellar pathways, the cerebellum receives information from the spinal cord indirectly via spino-bulbar-cerebellar systems. One of the structures in this pathway is the lateral reticular nucleus (LRt). We performed series of experiments to investigate the organisation and neurotransmitter content of Spinoreticular Tract (SRT) neurons in the lumbar spinal cord that project to the LRt. Three rats received injections of the b subunit of Cholera toxin (CTb) or Fluorogold (FG) within the left or right LRt. The majority of SRT cells (56-61%) were found within the contralateral medial intermediate grey matter where small numbers (7-10%) of double-labelled cells were also present on both sides of the cord. Six rats received unilateral spinal injections of CTb to label spinal projections to the LRt. Injections of FG were made also into the anterior lobe of the cerebellum to label LRt pre-cerebellar neurons. Terminals were found mainly ipsilateral to spinal injection sites within the central and ventrolateral regions of the LRt. Immunocytochemical analysis of SRT terminals revealed that the majority (75%) were contained vesicular glutamate transporter 2 but a minority (20%) contained the vesicular GABA transporter. The inhibitory subpopulation was found to be GABAergic, glycinergic or contained both transmitters. Inhibitory and excitatory terminals were present within overlapping regions of the nucleus. Most CTb terminals contacting LRt pre-cerebellar neurons were excitatory (80%) whereas a minority were inhibitory and most cells (88%) received contacts from both inhibitory and excitatory terminals. This study shows that SRT axons in the LRt have the capacity to exert direct excitatory and inhibitory actions on LRt pre-cerebellar neurons. Thus spinal cord input has the capacity to facilitate or depress the activity of individual LRt cells which in turn adjust activity in the cerebellum to produce coordinated motor behaviours

Peter J. Soja - One of the best experts on this subject based on the ideXlab platform.

  • spontaneous spike activity of Spinoreticular Tract neurons during sleep and wakefulness
    2001
    Co-Authors: Peter J. Soja, Niwat Taepavarapruk, Walton Pang, Shelly A. Mcerlane
    Abstract:

    Sleep mentation studies infer that pain sensation in humans may be reduced during active REM sleep. However, to provide a mechanistic explanation for this phenomenon, few, if any neurophysiological studies have been performed at the lumbar level from neurons comprising classical pain pathways during sleep and wakefulness. The Spinoreticular Tract is one such classical pathway that has been implicated in the rostral transmission of nociceptive information. The present study was performed to determine if the activity of Spinoreticular Tract (SRT) neurons is dependent upon behavioral state. Accordingly, extracellular recording techniques were used to monitor the activity of identified SRT neurons in unanesthetized chronic cats during sleep and wakefulness. The ongoing spike activity of SRT neurons was found to be relatively uniform when the states of quiet wakefulness and quiet sleep were compared. However, during active sleep, the majority of the SRT neurons sampled underwent a sustained reduction in spike activity. Marked facilitation of SRT cell activity occurred in a few instances. These data provide the first unitary evidence supporting earlier evoked potential, psychophysical and clinical studies that ascending sensory information in a classical pain pathway is regulated in a state-dependent fashion.

  • On the reduction of spontaneous and glutamate-driven spinocerebellar and Spinoreticular Tract neuronal activity during active sleep.
    2001
    Co-Authors: Peter J. Soja, Niwat Taepavarapruk, B E Cairns, Walton Pang, Shelly A. Mcerlane
    Abstract:

    AbsTract The present study was performed to provide evidence that dynamic neural processes underlie the reduction in dorsal spinocerebellar Tract and Spinoreticular Tract neuron activity that occurs during active sleep. To ascertain the effect of local inhibition on the spontaneous and glutamate-evoked spike discharge of sensory Tract neurons, preliminary control tests were performed during the state of quiet wakefulness, where GABA or glycine was co-administered in a sustained fashion during pulsatile release of glutamate to dorsal spinocerebellar Tract ( n =3) or Spinoreticular Tract ( n =2) neurons. Co-administration of GABA or glycine also resulted in a significant marked suppression of spontaneous spike activity and glutamate-evoked responses of these cells. Extracellular recording experiments combined with juxtacellular application of glutamate were then performed on 20 antidromically identified dorsal spinocerebellar Tract and Spinoreticular Tract neurons in the chronic intact cat as a function of sleep and wakefulness. The glutamate-evoked activity of a group of 10 sensory Tract neurons (seven dorsal spinocerebellar Tract, three Spinoreticular Tract), which exhibited a significant decrease in their spontaneous spike activity during active sleep, was examined. Glutamate-evoked activity in these cells was significantly attenuated during active sleep compared with wakefulness. In contrast, the glutamate-evoked activity of a second group of eight sensory Tract neurons (four dorsal spinocerebellar Tract, four Spinoreticular Tract), which exhibited a significant increase in their spontaneous spike activity during active sleep, was not significantly altered in a state-dependent manner. These data indicate that, during natural active sleep, a dynamic neural process is engaged onto certain dorsal spinocerebellar Tract and Spinoreticular Tract neurons, which in turn dampens sensory throughput to higher brain centers.

Zilli Huma - One of the best experts on this subject based on the ideXlab platform.

  • the spino bulbar cerebellar pathway organization and neurochemical properties of spinal cells that project to the lateral reticular nucleus in the rat
    2015
    Co-Authors: Zilli Huma, D J Maxwell
    Abstract:

    In addition to classical spinocerebellar pathways, the cerebellum receives information from the spinal cord indirectly via spino-bulbar-cerebellar systems. One of the structures in this pathway is the lateral reticular nucleus (LRt). We performed series of experiments to investigate the organization and neurotransmitter content of Spinoreticular Tract (SRT) neurons in the lumbar spinal cord that project to the LRt. Three rats received injections of the b subunit of Cholera toxin (CTb) or Fluorogold (FG) within the left and right LRt. The majority of SRT cells (56–61%) were found within the contralateral medial intermediate gray matter where small numbers (7–10%) of double-labeled cells were also present on both sides of the cord. Six rats received unilateral spinal injections of CTb to label spinal projections to the LRt. Injections of FG were made also into the anterior lobe of the cerebellum to label LRt pre-cerebellar neurons. Terminals were found mainly ipsilateral to spinal injection sites within the central and ventrolateral regions of the LRt. Immunocytochemical analysis of SRT terminals revealed that the majority (75%) were contained vesicular glutamate transporter 2 but a minority (20%) contained the vesicular GABA transporter. The inhibitory subpopulation was found to be GABAergic, glycinergic, or contained both transmitters. Inhibitory and excitatory terminals were present within overlapping regions of the nucleus. Most CTb terminals contacting LRt pre-cerebellar neurons were excitatory (80%) whereas a minority were inhibitory and most cells (88%) received contacts from both inhibitory and excitatory terminals. This study shows that SRT axons in the LRt have the capacity to exert direct excitatory and inhibitory actions on LRt pre-cerebellar neurons. Thus spinal cord input has the capacity to facilitate or depress the activity of individual LRt cells which in turn adjust activity in the cerebellum to produce coordinated motor behaviors.

Niwat Taepavarapruk - One of the best experts on this subject based on the ideXlab platform.

  • spontaneous spike activity of Spinoreticular Tract neurons during sleep and wakefulness
    2001
    Co-Authors: Peter J. Soja, Niwat Taepavarapruk, Walton Pang, Shelly A. Mcerlane
    Abstract:

    Sleep mentation studies infer that pain sensation in humans may be reduced during active REM sleep. However, to provide a mechanistic explanation for this phenomenon, few, if any neurophysiological studies have been performed at the lumbar level from neurons comprising classical pain pathways during sleep and wakefulness. The Spinoreticular Tract is one such classical pathway that has been implicated in the rostral transmission of nociceptive information. The present study was performed to determine if the activity of Spinoreticular Tract (SRT) neurons is dependent upon behavioral state. Accordingly, extracellular recording techniques were used to monitor the activity of identified SRT neurons in unanesthetized chronic cats during sleep and wakefulness. The ongoing spike activity of SRT neurons was found to be relatively uniform when the states of quiet wakefulness and quiet sleep were compared. However, during active sleep, the majority of the SRT neurons sampled underwent a sustained reduction in spike activity. Marked facilitation of SRT cell activity occurred in a few instances. These data provide the first unitary evidence supporting earlier evoked potential, psychophysical and clinical studies that ascending sensory information in a classical pain pathway is regulated in a state-dependent fashion.

  • On the reduction of spontaneous and glutamate-driven spinocerebellar and Spinoreticular Tract neuronal activity during active sleep.
    2001
    Co-Authors: Peter J. Soja, Niwat Taepavarapruk, B E Cairns, Walton Pang, Shelly A. Mcerlane
    Abstract:

    AbsTract The present study was performed to provide evidence that dynamic neural processes underlie the reduction in dorsal spinocerebellar Tract and Spinoreticular Tract neuron activity that occurs during active sleep. To ascertain the effect of local inhibition on the spontaneous and glutamate-evoked spike discharge of sensory Tract neurons, preliminary control tests were performed during the state of quiet wakefulness, where GABA or glycine was co-administered in a sustained fashion during pulsatile release of glutamate to dorsal spinocerebellar Tract ( n =3) or Spinoreticular Tract ( n =2) neurons. Co-administration of GABA or glycine also resulted in a significant marked suppression of spontaneous spike activity and glutamate-evoked responses of these cells. Extracellular recording experiments combined with juxtacellular application of glutamate were then performed on 20 antidromically identified dorsal spinocerebellar Tract and Spinoreticular Tract neurons in the chronic intact cat as a function of sleep and wakefulness. The glutamate-evoked activity of a group of 10 sensory Tract neurons (seven dorsal spinocerebellar Tract, three Spinoreticular Tract), which exhibited a significant decrease in their spontaneous spike activity during active sleep, was examined. Glutamate-evoked activity in these cells was significantly attenuated during active sleep compared with wakefulness. In contrast, the glutamate-evoked activity of a second group of eight sensory Tract neurons (four dorsal spinocerebellar Tract, four Spinoreticular Tract), which exhibited a significant increase in their spontaneous spike activity during active sleep, was not significantly altered in a state-dependent manner. These data indicate that, during natural active sleep, a dynamic neural process is engaged onto certain dorsal spinocerebellar Tract and Spinoreticular Tract neurons, which in turn dampens sensory throughput to higher brain centers.