Role of corticobulbar projection neurons in cortically induced rhythmical masticatory jaw-opening movement in the guinea pig

Nozaki, Shuichi; Iriki, Atsushi; Nakamura, Yoshio

doi:10.1152/jn.1986.55.4.826

Cited by 59 publications

(29 citation statements)

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“…These neurons are thought to activate another group lying more dorsally in the same region. In the original model, the latter group, which fires rhythmically during fictive mastication, were the premotoneurons that controlled trigeminal motoneurons (Nozaki et al, 1986b). However, projections from this area to N Vmt are very sparse (Travers and Norgren, 1983;Landgren et al, 1986), so a relay in caudal N reticularis parvocellularis was added (Nozaki et al, 1993;Nakamura and Katakura, 1995).…”

Section: Do Rpc-␣ and Nvspo-␥ Neurons Play Different Roles In Masticamentioning

confidence: 99%

Evidence that Trigeminal Brainstem Interneurons Form Subpopulations to Produce Different Forms of Mastication in the Rabbit

et al. 1998

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To determine how trigeminal brainstem interneurons pattern different forms of rhythmical jaw movements, four types of motor patterns were induced by electrical stimulation within the cortical masticatory areas of rabbits. After these were recorded, animals were paralyzed and fictive motor output was recorded with an extracellular microelectrode in the trigeminal motor nucleus. A second electrode was used to record from interneurons within the lateral part of the parvocellular reticular formation (Rpc-␣, n ϭ 28) and ␥-subnucleus of the oral nucleus of the spinal trigeminal tract (NVspo-␥, n ϭ 68). Both of these areas contain many interneurons projecting to the trigeminal motor nucleus.The basic characteristics of the four movement types evoked before paralysis were similar to those seen after the neuromuscular blockade, although cycle duration was significantly decreased for all patterns.Interneurons showed three types of firing pattern: 54% were inactive, 42% were rhythmically active, and 4% had a tonic firing pattern. Neurons within the first two categories were intermingled in Rpc-␣ and NVspo-␥: 48% of rhythmic neurons were active during one movement type, 35% were active during two, and 13% were active during three or four patterns.Most units fired during either the middle of the masseter burst or interburst phases during fictive movements evoked from the left caudal cortex. In contrast, there were no tendencies toward a preferred coupling of interneuron activity to any particular phase of the cycle during stimulation of other cortical sites. It was concluded that the premotoneurons that form the final commands to trigeminal motoneurons are organized into subpopulations according to movement pattern.Key words: rhythmical movements; pattern generation; mastication; trigeminal system; brainstem; rabbit To be effective, motor patterns need to be adapted to the needs of the organism. As a result, the same body parts often participate in several stereotyped behaviors that differ only in the ordering and scaling of commands to the same pools of motoneurons (e.g., walking vs running and chewing on the right vs chewing on the left). The way in which neural circuits generate these different patterns has been investigated in many species, particularly in invertebrates, and evidence has been found that three basic forms of architecture exist: dedicated circuitry, distributed circuitry, and reorganizing circuitry (for review, see Morton and Chiel, 1994). It is probable, however, that most of the circuits controlling complex movements have features of more than one of the basic models.Dedicated circuits can generate only one pattern, and when they are triggered by a sensory input, they suppress other ongoing behaviors. The circuit that generates wing retraction in the mollusk Clione limacina seems to be an example of this type (Morton and Chiel, 1994). Reorganizing circuits generate different patterns when the effectiveness of synaptic connections between members of the total population of neurons changes. The key feature...

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Section: Do Rpc-␣ and Nvspo-␥ Neurons Play Different Roles In Masticamentioning

confidence: 99%

Evidence that Trigeminal Brainstem Interneurons Form Subpopulations to Produce Different Forms of Mastication in the Rabbit

et al. 1998

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“…On the one hand, the heptapeptide participates in this process by directly acting on the central machinery for circulatory control [12-18, 20, 21 ]. On the other, it also influences cardiovas cular functions by affecting fluid volume, and 68 Y ang/Kuo/Chan/Chan Neurobiology of Central Angiotensin III and Dipsogenesis hence cardiac output, via regulation of water homeostasis. The maintenance of water homeostasis is of course one of the essential physiologic re quirements for the survival of terrestrial ani mals.…”

Section: Discussionmentioning

confidence: 99%

“…Based on latency data from electrophysiologic studies, Lowe [56] proposed that craniohypoglossal reflexes are multisynaptic, and may involve relay neurons whose locations are within the brain stem. Although anatomic evidence [57,58] implicates the lat eral reticular formation (chiefly nucleus reti cularis parvocellularis) as containing such re- 66 Yang/Kuo/Chan/Chan Neurobiology of Central Angiotensin III and Dipsogcncsis As one of the major reticular nuclei in the medulla oblongata, the nucleus reticularis gigantocellularis (NRGC) is involved in both the processing of sensory information [59][60][61][62] and control of postural muscle tone [63][64][65][66], F.lectrophysiologic evidence also suggests that the NRGC participates in the regulation of cortically induced rhythmical masticatory jaw-opening movement in the guinea pig [67,68], Suzuki and Siegel [69] reported that a small number of cells in the medial reticular formation, including the NRGC, change their discharge rates in relation to tongue move ment. They suggest that these neurons may be involved in tongue-jaw coordination during mastication, licking and grooming in the un anesthetized cat.…”

Section: Nucleus Reticularis Gigantocelluiaris Hypoglossal Nucleus Amentioning

confidence: 99%

Neurobiology of Central Angiotensin III and Dipsogenesis

et al. 1995

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“…The lateral pterygoid and suprahyoid (SH; anterior belly of the digastric, geniohyoid and mylohyoid) muscles constitute the jaw opening muscles (or jaw openers), while the temporalis, masseter (Mass) and medial pterygoid muscles serve as the jaw closing muscles (or jaw closers). Chewing movements, which usually begin with jaw opening and are followed by jaw closing, have been noted among many mammalian species, including humans [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

“…Two groups of nuclei, the paragigantocellular and gigantocellular reticular nuclei, and the medial bulbar reticular formation, located in the region of the medulla oblongata, are believed to play essential roles in the central pattern generator that controls the basic chewing rhythm [1][2][3]. Neurons of either or both nucleus groups send action potentials, via the parvocellular reticular nucleus, to the jaw opening and closing motoneurons, innervating the muscles responsible for chewing movement [4].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Masseter Activity Patterns during Chewing on Suprahyoid Activity in Subsequent Chewing Cycles

Miyaoka¹,

Ashida²,

Iwamori³

et al. 2014

JBBS

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Few studies have evaluated the effects of activity patterns of the jaw closing muscles assessed by specific parameters on jaw opening in subsequent cycles during the chewing of food. The objective of this study was to quantitatively analyze the effect of the masseter (jaw closer) activity patterns on suprahyoid (jaw opener) activity during subsequent cycles. The assessments were performed while participants naturally chewed six test foods that differed in size dimensions and textural properties. Surface electromyograms of the masseter (on the habitual working side) and suprahyoid muscles were recorded in ten healthy young adults, each of whom randomly received one of the six test foods. The activity patterns were assessed using three parameters specifically developed for their quantification. Changes in suprahyoid activity during each of the subsequent chewing cycles were examined by three amplitudinal (minimum, maximum, and net values of the integrated suprahyoid electromyogram) parameters and one durational (active duration) parameter. The main finding was that two of the three activity pattern parameters had a statistically significant effect only on the three amplitudinal parameters in three of the six test foods. These results suggest that masseter activity patterns partially affect suprahyoid activity during subsequent chewing cycles and that the effect is food dependent. A possible neural mechanism responsible for this effect is presented.

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Role of corticobulbar projection neurons in cortically induced rhythmical masticatory jaw-opening movement in the guinea pig

Cited by 59 publications

References 0 publications

Evidence that Trigeminal Brainstem Interneurons Form Subpopulations to Produce Different Forms of Mastication in the Rabbit

Evidence that Trigeminal Brainstem Interneurons Form Subpopulations to Produce Different Forms of Mastication in the Rabbit

Neurobiology of Central Angiotensin III and Dipsogenesis

The Effect of Masseter Activity Patterns during Chewing on Suprahyoid Activity in Subsequent Chewing Cycles

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