A Study of Jaw Reflexes of the Awake Cat during Mastication and Locomotion

Lund, James P.; Drew, Trevor; Rossignol, Serge

doi:10.1159/000118860

Cited by 49 publications

(22 citation statements)

References 22 publications

(25 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chewing is a repetitive motor activity, which, like locomotion and respiration, is driven by cellular networks within the central nervous system (Lund et al, 1984a;Stein et al, 1997). These networks are termed the central pattern generator (CPG).…”

Section: (Iii) Physiology Of Rhythmic Movementsmentioning

confidence: 99%

Neurobiological Mechanisms Involved in Sleep Bruxism

Lavigne

Kato

Kolta

et al. 2003

Critical Reviews in Oral Biology & Medicine

441

290

View full text Add to dashboard Cite

Sleep bruxism (SB) is reported by 8% of the adult population and is mainly associated with rhythmic masticatory muscle activity (RMMA) characterized by repetitive jaw muscle contractions (3 bursts or more at a frequency of 1 Hz). The consequences of SB may include tooth destruction, jaw pain, headaches, or the limitation of mandibular movement, as well as tooth-grinding sounds that disrupt the sleep of bed partners. SB is probably an extreme manifestation of a masticatory muscle activity occurring during the sleep of most normal subjects, since RMMA is observed in 60% of normal sleepers in the absence of grinding sounds. The pathophysiology of SB is becoming clearer, and there is an abundance of evidence outlining the neurophysiology and neurochemistry of rhythmic jaw movements (RJM) in relation to chewing, swallowing, and breathing. The sleep literature provides much evidence describing the mechanisms involved in the reduction of muscle tone, from sleep onset to the atonia that characterizes rapid eye movement (REM) sleep. Several brainstem structures (e.g., reticular pontis oralis, pontis caudalis, parvocellularis) and neurochemicals (e.g., serotonin, dopamine, gamma aminobutyric acid [GABA], noradrenaline) are involved in both the genesis of RJM and the modulation of muscle tone during sleep. It remains unknown why a high percentage of normal subjects present RMMA during sleep and why this activity is three times more frequent and higher in amplitude in SB patients. It is also unclear why RMMA during sleep is characterized by co-activation of both jaw-opening and jawclosing muscles instead of the alternating jaw-opening and jaw-closing muscle activity pattern typical of chewing. The final section of this review proposes that RMMA during sleep has a role in lubricating the upper alimentary tract and increasing airway patency. The review concludes with an outline of questions for future research.

show abstract

Section: (Iii) Physiology Of Rhythmic Movementsmentioning

confidence: 99%

Neurobiological Mechanisms Involved in Sleep Bruxism

Lavigne

Kato

Kolta

et al. 2003

Critical Reviews in Oral Biology & Medicine

441

290

View full text Add to dashboard Cite

show abstract

“…However, their finding is not conclusive because during locomotion jaw position must be actively held against destabilizing inertial and gravitational forces. Serotonergic activity may have been increased by higher nervous centers to augment the gain of the stretch reflex of the jaw-closing muscles and, consequently, stiffness of muscles (17).…”

mentioning

confidence: 99%

Serotonergic neurons in the caudal raphe nuclei discharge in association with activity of masticatory muscles

Le¹

1997

Braz J Med Biol Res

View full text Add to dashboard Cite

There is a dense serotonergic projection from nucleus raphe pallidus and nucleus raphe obscurus to the trigeminal motor nucleus and serotonin exerts a strong facilitatory action on the trigeminal motoneurons. Some serotonergic neurons in these caudal raphe nuclei increase their discharge during feeding. The objective of the present study was to investigate the possibility that the activity of these serotonergic neurons is related to activity of masticatory muscles. Cats were implanted with microelectrodes and gross electrodes. Caudal raphe single neuron activity, electrocorticographic activity, and splenius, digastric and masseter electromyographic activities were recorded during active behaviors (feeding and grooming), during quiet waking and during sleep. Seven presumed serotonergic neurons were identified. These neurons showed a long duration action potential (>2.0 msec), and discharged slowly (2-7 Hz) and very regularly (interspike interval coefficient of variation <0.3) during quiet waking. The activity of these neurons decreased remarkably during fast wave sleep (78-100%). Six of these neurons showed tonic changes in their activity positively related to digastric and/or masseter muscles activity but not to splenius muscle activity during waking. These data are consistent with the hypothesis that serotonergic neurons in the caudal raphe nuclei play an important role in the control of jaw movements.

show abstract

“…Motion-dependent loads to the jaw have been studied previously in locomotion (Murray, 1967;Lund et al, 1984). In both cats and humans, the intrinsic stiffness of jaw muscles and stretch reflexes have been shown to counteract loads associated with head motion (Lund et al, 1984).…”

Section: Discussionmentioning

confidence: 99%

“…In both cats and humans, the intrinsic stiffness of jaw muscles and stretch reflexes have been shown to counteract loads associated with head motion (Lund et al, 1984). Other reflex-based compensations may arise in vestibular receptors and neck muscles that influence jaw-closer motoneurons (Funakoshi and Amano, 1973;Griffiths et al, 1983).…”

Section: Discussionmentioning

confidence: 99%