The effect of procaine injection into the medullary reticular formation on forelimb muscle activity evoked by mesencephalic locomotor region and vestibular stimulation in the decerebrated guinea-pig

Marlinsky, V.V.; Voitenko, L. P.

doi:10.1016/0306-4522(91)90287-x

Cited by 16 publications

(9 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Stimulation of the MLR on one side is known to generate bilaterally symmetrical locomotor movements and to control the intensity of locomotor output in tetrapods (cat: Shik et al, ; guinea‐pig: Marlinsky et al, ; rabbit: Musienko et al, ; salamander: Cabelguen et al, ). The neural mechanisms by which the symmetry occurs are still unresolved and we examined this in salamanders.…”

Section: Resultsmentioning

confidence: 99%

“…Stimulation of the MLR on one side was shown to generate bilaterally symmetrical locomotor movements in the cat (Shik et al, ; Musienko et al, ), lampreys (Sirota et al, ; Brocard et al, ), stingrays (Bernau et al, ), rabbits (Musienko et al, ), and guinea‐pigs (Marlinksy and Voitenko, ). In lampreys, it was proposed that this resulted at least in part from bilaterally symmetrical inputs from the MLR to RS cells on the basis of anatomical tracing, intracellular recordings, and Ca 2+ imaging of RS cells (Brocard et al, ).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

The mesencephalic locomotor region sends a bilateral glutamatergic drive to hindbrain reticulospinal neurons in a tetrapod

Ryczko

Auclair

Cabelguen

et al. 2015

J of Comparative Neurology

105

View full text Add to dashboard Cite

In vertebrates, stimulation of the mesencephalic locomotor region (MLR) on one side evokes symmetrical locomotor movements on both sides. How this occurs was previously examined in detail in a swimmer using body undulations (lamprey), but in tetrapods the downstream projections from the MLR to brainstem neurons are not fully understood. Here we examined the brainstem circuits from the MLR to identified reticulospinal neurons in the salamander Notophthalmus viridescens. Using neural tracing, we show that the MLR sends bilateral projections to the middle reticular nucleus (mRN, rostral hindbrain) and the inferior reticular nucleus (iRN, caudal hindbrain). Ca2+ imaging coupled to electrophysiology in in vitro isolated brains revealed very similar responses in reticulospinal neurons on both sides to a unilateral MLR stimulation. As the strength of MLR stimulation was increased, the responses increased in size in reticulospinal neurons of the mRN and iRN, but the responses in the iRN were smaller. Bath‐application or local microinjections of glutamatergic antagonists markedly reduced reticulospinal neuron responses, indicating that the MLR sends glutamatergic inputs to reticulospinal neurons. In addition, reticulospinal cells responded to glutamate microinjections and the size of the responses paralleled the amount of glutamate microinjected. Immunofluorescence coupled with anatomical tracing confirmed the presence of glutamatergic projections from the MLR to reticulospinal neurons. Overall, we show that the brainstem circuits activated by the MLR in the salamander are organized similarly to those previously described in lampreys, indicating that the anatomo‐physiological features of the locomotor drive are well conserved in vertebrates. J. Comp. Neurol. 524:1361–1383, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

The mesencephalic locomotor region sends a bilateral glutamatergic drive to hindbrain reticulospinal neurons in a tetrapod

Ryczko

Auclair

Cabelguen

et al. 2015

J of Comparative Neurology

105

View full text Add to dashboard Cite

show abstract

“…The MLR was initially found in cats to initiate locomotion and control its frequency and intensity (Shik et al, 1966). It was later identified in lamprey (Sirota et al, 2000), salamander (Cabelguen et al, 2003), stingray (Bernau et al, 1991), bird (Sholomenko et al, 1991), rat (Garcia-Rill et al, 1987), mouse (Lee et al, 2014; Roseberry et al, 2016), rabbit (Musienko et al, 2008), guinea-pig (Marlinsky and Voitenko, 1991), and monkey (Eidelberg et al, 1981; Karachi et al, 2010; Goetz et al, 2016a). In basal vertebrates, the MLR comprises the laterodorsal tegmental nucleus and the pedunculopontine nucleus (PPN).…”

Section: Ascending Dopaminergic Pathway and Locomotionmentioning

confidence: 99%

Dopamine and the Brainstem Locomotor Networks: From Lamprey to Human

2017

View full text Add to dashboard Cite

In vertebrates, dopamine neurons are classically known to modulate locomotion via their ascending projections to the basal ganglia that project to brainstem locomotor networks. An increased dopaminergic tone is associated with increase in locomotor activity. In pathological conditions where dopamine cells are lost, such as in Parkinson's disease, locomotor deficits are traditionally associated with the reduced ascending dopaminergic input to the basal ganglia. However, a descending dopaminergic pathway originating from the substantia nigra pars compacta was recently discovered. It innervates the mesencephalic locomotor region (MLR) from basal vertebrates to mammals. This pathway was shown to increase locomotor output in lampreys, and could very well play an important role in mammals. Here, we provide a detailed account on the newly found dopaminergic pathway in lamprey, salamander, rat, monkey, and human. In lampreys and salamanders, dopamine release in the MLR is associated with the activation of reticulospinal neurons that carry the locomotor command to the spinal cord. Dopamine release in the MLR potentiates locomotor movements through a D1-receptor mechanism in lampreys. In rats, stimulation of the substantia nigra pars compacta elicited dopamine release in the pedunculopontine nucleus, a known part of the MLR. In a monkey model of Parkinson's disease, a reduced dopaminergic innervation of the brainstem locomotor networks was reported. Dopaminergic fibers are also present in human pedunculopontine nucleus. We discuss the conserved locomotor role of this pathway from lamprey to mammals, and the hypothesis that this pathway could play a role in the locomotor deficits reported in Parkinson's disease.

show abstract

“…In mammals, neurophysiological investigations have demonstrated that the medial medullary reticular formation plays an important role in goal-directed behavior by relaying MLR inputs to the spinal locomotor networks via the ventrolateral funiculus (Atsuta et al 1990;Garcia-Rill and Skinner 1987a,b;Iwakiri et al 1995;Marlinsky and Voitenko 1991;Noga et al 1991;Orlovsky 1970). These findings are supported by neuroanatomical evidence showing dense projections to the med-ullary reticular formation from MLR, specifically to the n. gigantocellularis and n. magnocellularis (Lai et al 1999;Skinner et al 1990;Steeves and Jordan 1984).…”

Section: Comparative Aspectsmentioning

confidence: 99%

Differential Contribution of Reticulospinal Cells to the Control of Locomotion Induced By the Mesencephalic Locomotor Region

Brocard

Dubuc

2003

Journal of Neurophysiology

View full text Add to dashboard Cite

In lampreys as in other vertebrates, the reticulospinal (RS) system relays inputs from the mesencephalic locomotor region (MLR) to the spinal locomotor networks. Semi-intact preparations of larval sea lamprey were used to determine the relative contribution of the middle (MRRN) and the posterior (PRRN) rhombencephalic reticular nuclei to swimming controlled by the MLR. Intracellular recordings were performed to examine the inputs from the MLR to RS neurons. Stimulation of the MLR elicited monosynaptic excitatory responses of a higher magnitude in the MRRN than in the PRRN. This differential effect was not attributed to intrinsic properties of RS neurons. Paired recordings showed that at threshold intensity for swimming, spiking activity was primarily elicited in RS cells of the MRRN. Interestingly, cells of the PRRN began to discharge at higher stimulation intensities only when MRRN cells had reached their maximal discharge rate. Glutamate antagonists were ejected in either nucleus to reduce their activity. Ejections over the MRRN increased the stimulation threshold for evoking locomotion and resulted in a marked decrease in the swimming frequency and the strength of the muscle contractions. Ejections over the PRRN decreased the frequency of swimming. This study provides support for the concept that RS cells show a specific recruitment pattern during MLR-induced locomotion. RS cells in the MRRN are primarily involved in initiation and maintenance of low-intensity swimming. At higher frequency locomotor rhythm, RS cells in both the MRRN and the PRRN are recruited.

show abstract

The effect of procaine injection into the medullary reticular formation on forelimb muscle activity evoked by mesencephalic locomotor region and vestibular stimulation in the decerebrated guinea-pig

Cited by 16 publications

References 43 publications

The mesencephalic locomotor region sends a bilateral glutamatergic drive to hindbrain reticulospinal neurons in a tetrapod

The mesencephalic locomotor region sends a bilateral glutamatergic drive to hindbrain reticulospinal neurons in a tetrapod

Dopamine and the Brainstem Locomotor Networks: From Lamprey to Human

Differential Contribution of Reticulospinal Cells to the Control of Locomotion Induced By the Mesencephalic Locomotor Region

Contact Info

Product

Resources

About