Integration of vestibular and gastrointestinal inputs by cerebellar fastigial nucleus neurons: multisensory influences on motion sickness

Abstract

Previous studies demonstrated that ingestion of the emetic compound copper sulfate (CuSO4) alters the responses to vestibular stimulation of a large fraction of neurons in brainstem regions that mediate nausea and vomiting, thereby affecting motion sickness susceptibility. Other studies suggested that the processing of vestibular inputs by cerebellar neurons plays a critical role in generating motion sickness, and that neurons in the cerebellar fastigial nucleus receive visceral inputs. These findings raised the hypothesis that stimulation of gastrointestinal receptors by a nauseogenic compound affects the processing of labyrinthine signals by fastigial nucleus neurons. We tested this hypothesis in decerebrate cats by determining the effects of intragastric injection of CuSO4 on the responses of rostral fastigial nucleus to whole-body rotations that activate labyrinthine receptors. Responses to vestibular stimulation of fastigial nucleus neurons were more complex in decerebrate cats than reported previously in conscious felines. In particular, spatiotemporal convergence (STC) responses, which reflect the convergence of vestibular inputs with different spatial and temporal properties, were more common in decerebrate than in conscious felines. The firing rate of a small percentage of fastigial nucleus neurons (15%) was altered over 50% by the administration of CuSO4; the firing rate of the majority of these cells decreased. The responses to vestibular stimulation of a majority of these cells were attenuated after the compound was provided. Although these data support our hypothesis, the low fraction of fastigial nucleus neurons whose firing rate and responses to vestibular stimulation were affected by the administration of CuSO4 cast doubt on the notion that nauseogenic visceral inputs modulate motion sickness susceptibility principally through neural pathways that include the cerebellar fastigial nucleus. Instead, it appears that convergence of gastrointestinal and vestibular inputs occurs mainly in the brainstem.

Central Positional Nystagmus: A Systematic Literature Review

“…This review found that vomiting almost always occurred in the presence of vertigo in a variety of space occupying lesions. The cause of vomiting may be due to lesion-related pressure effects on the area postrema in the caudal aspect of the floor for the fourth ventricle ( 33 ), or related to affectation of cerebellar and brainstem pathways involved in the integration of vestibular and non-vestibular afferents relating to body position in space ( 42 ).…”

Hindlimb movement modulates the activity of rostral fastigial nucleus neurons that process vestibular input

“…Such responses are due to convergence of vestibular inputs with different spatial and temporal characteristics, and are thus referred to as spatiotemporal convergence (STC) responses (Schor and Angelaki 1992; Moy et al 2012). STC responses have previously been reported to be common amongst rFN neurons in the decerebrate cat (Catanzaro et al 2014). Twenty percent of rFN neurons (1/5) with directional encoding of hindlimb movement had STC responses, whereas 67% of rFN neurons (8/12) without directional encoding had STC responses.…”

“…For example, responses could be different if the limb movement was self-generated instead of passive. Furthermore, differences in preparation sometimes have significant effects on the behavior of neural networks, such that the same stimulus will elicit different responses if the animal is decerebrate or conscious (Destefino et al 2011; Catanzaro et al 2014). Therefore, follow-up studies in conscious animals, which incorporate both active and passive hindlimb movements, should shed light on how hindlimb movements are processed by rFN neurons, and may provide further insights regarding the relevance of these signals in postural control.…”

Granisetron vs. Granisetron and Dexamethasone on The Reduction of Postoperative Nausea and Vomiting (PONV) After Caesarean Section With Intrathecal Morphine: A Randomised Controlled Trial

“…PONV is one of the complex entities in anaesthesia. Its pathophysiology involves various receptors and afferent pathways, in which the primary ones are the stimulation of vagal mucosal pathway of the gastrointestinal system by paracrine activity, the stimulation of the chemoreceptor trigger zone (CTZ) [14], the vestibular system [15], area postrema of the midbrain [16] and afferent pathways from the cerebral cortex. Inhibition of any of these pathways would prevent transmission of impulses to the nucleus tracts solitarius (NTS), thus avoiding emesis.…”