Modulatory Effects of Theta Burst Stimulation on Cerebellar Nonsomatic Functions

Abstract

Clinical and functional imaging studies suggest that the cerebellar vermis is involved in the regulation of a range of nonsomatic functions including cardiovascular control, thirst, feeding behavior, and primal emotions. Cerebello-hypothalamic circuits have been postulated to be a potential neuroanatomical substrate underlying this modulation. We tested this putative relationship between the cerebellar vermis and nonsomatic functions by stimulating the cerebellum noninvasively via neuronavigated transcranial magnetic stimulation. In this randomized, counter-balanced, within-subject study, intermittent theta burst stimulation (TBS) was applied on three different days to the vermis and the right and left cerebellar hemispheres of 12 right-handed normal subjects with the aim of modulating activity in the targeted cerebellar structure. TBS-associated changes were investigated via cardiovascular monitoring, a series of emotionally arousing picture stimuli, subjective analog scales for primal emotions, and the Profile of Mood States test. All 36 sessions of cerebellar stimulation were tolerated well without serious adverse events. Cardiovascular monitoring pointed to a mild but significant decrease in heart rate subsequent to vermal stimulation; no changes were detected in systolic or diastolic blood pressure measurements. Subjective ratings detected a significant increase in Thirst and a trend toward increased Appetite following vermal stimulation. These observations are consistent with existing neurophysiological and neuroimaging data indicating a role for the cerebellum in the regulation of visceral responses. In conjunction with the modulatory function of the cerebellum, our results suggest a role for the vermis in somatovisceral integration likely through cerebello-hypothalamic pathways. Further research is warranted to elucidate the potential mechanisms underlying the cerebellar modulation of nonsomatic functions.

Non-invasive brain stimulation and the autonomic nervous system

“…Regarding TMS, other targets have been implicated in the ANS modulation in humans, such as the spinal cord (Paxton et al, 2011) and cerebellum (Demirtas-Tatlidede et al, 2011). Therefore, these two regions (spinal cord and cerebellum) should be further explored in future studies addressing ANS modulation induced by NIBS.…”

Cerebellar Zones: History, Development, and Function

“…In this special issue, Jeremy Schmahmann and colleagues examine the putative function of cerebellarhypothalamic pathways using intermittent theta burst stimulation to modulate activity in experimentally targeted regions of the cerebellum [13]. Although clearly the resolution of zonal architecture is not as detailed as anatomical studies reveal, the authors present two important findings: (1) the cerebellum may modulate several non-somatic functions including cardiovascular control, thirst, and feeding and (2) the control of these functions appears to be regionally localized with a major influence coming from the posterior cerebellar vermis.…”

Medial cerebellar nucleus projects to feeding-related neurons in the ventromedial hypothalamic nucleus in rats

“…By means of ectomy and lesion techniques, previous behavioral studies have revealed that the cerebellum is involved in diverse facets of feeding behavior, such as nutritional metabolism, taste preferences and body weight gain (Scalera 1991;Mahler et al 1993;Colombel et al 2002). Furthermore, evidence from clinical and functional imaging studies suggests that the cerebellum is closely related to hunger, satiation, thirst, glucose intake and appetite (Schmahmann et al 1999;Tataranni et al 1999;Liu et al 2000;Parsons et al 2000;Demirtas-Tatlidede et al 2011).…”