Cerebellar modulation of feeding-related neurons in rat dorsomedial hypothalamic nucleus

Dysphagia following cerebellar stroke: analyzing the contribution of the cerebellum to swallowing function

Swallowing is essential for human health, and the cerebellum is crucial for motor movement regulation. Cerebellar strokes may cause dysphagia, but their exact effects remain unexplored in swallowing function. Therefore, the aim of this study was to analyze the precise clinical characteristics of the oral and pharyngeal phases of swallowing after cerebellar stroke and to critically discuss the cerebellum's contribution to swallowing. The study involved 34 participants with cerebellar strokes, gathered through convenience sampling. Neurologists diagnosed isolated strokes, and a speech and language pathologist examined swallowing ability using the Mann Assessment of Swallowing Ability. The study found that 52.9% of people experienced dysphagia after a cerebellar stroke. Dysphagia was significantly associated with a higher risk of aspiration. Age was also significantly correlated with dysphagia. No significant correlation was found between swallowing ability and sex. In conclusion, this study suggests isolated cerebellar stroke can adversely affect the motor and non-motor aspects of swallowing and cause severe dysphagia and aspiration risk. Thus, early diagnosis and timely management of dysphagia following a cerebellar stroke can help prevent serious consequences.

A case of postoperative cerebellar mutism with hyperphagia in a child following gross total resection of medulloblastoma occupying the cerebellar vermis

INTRODUCTION

Cerebellar mutism syndrome is a well-known complication following posterior fossa tumor resection. Its incidence is markedly increased among patients with medulloblastoma. Patients typically present with an inability to communicate verbally due to disruption of the dentato-thalamocortical pathway.

CASE DESCRIPTION

We present a unique case of cerebellar mutism in a three-year-old girl who underwent gross total resection of medulloblastoma occupying the cerebellar vermis. In addition to mutism, the patient developed hyperphagia.

DISCUSSION

This case report aims to contribute to current understanding of the role of cerebello-hypothalamic connections in cerebellar mutism and their clinical significance.

CTRP14 inactivation alters physical activity and food intake response to fasting and refeeding

Secreted proteins of the C1q/TNF-related protein (CTRP) family play diverse functions in different organ systems. In the brain, CTRP14/C1QL1 is required for the proper establishment and maintenance of synapses between climbing fibers and cerebellar Purkinje cells. Beyond the central nervous system, the function of CTRP14 is largely unknown. A recent genome-wide association study has implicated CTRP14/C1QL1 as a candidate gene associated with total body fat mass. Here, we explored the potential metabolic roles of CTRP14. We show that Ctrp14 expression in peripheral tissues is dynamically regulated by fasting-refeeding and high-fat feeding. In the chow-fed basal state, Ctrp14 deletion modestly reduces glucose tolerance in knockout (KO) male mice and affects physical activity in a sex- and nutritional state-dependent manner. In the ad libitum fed state, Ctrp14 KO male mice have lower physical activity. In contrast, female KO mice have increased physical activity in the fasted and refed states. In response to an obesogenic diet, CTRP14-deficient mice of either sex gained similar weight and are indistinguishable from wild-type littermates in body composition, lipid profiles, and insulin sensitivity. Ambulatory activity, however, is reduced in Ctrp14 KO male mice. Food intake is also reduced in Ctrp14 KO male mice in the refed period following food deprivation. Meal pattern analyses indicate that decreased caloric intake from fasting to refeeding is due, in part, to smaller meal size. We conclude that CTRP14 is largely dispensable for metabolic homeostasis, but highlight context-dependent and sexually dimorphic metabolic responses of Ctrp14 deletion affecting physical activity and ingestive behaviors.NEW & NOTEWORTHY CTRP14 is a secreted protein whose function in the peripheral tissues is largely unknown. We show that the expression of Ctrp14 in peripheral tissues is regulated by metabolic and nutritional state. We generated mice lacking CTRP14 and show that CTRP14 deficiency alters physical activity and food intake in response to fasting and refeeding. Our data has provided new and valuable information on the physiological function of CTRP14.

Cerebellum-Specific Deletion of the GABAA Receptor δ Subunit Leads to Sex-Specific Disruption of Behavior

Granule cells (GCs) of the cerebellar input layer express high-affinity δ GABA_A subunit-containing GABA_A receptors (δGABA_ARs) that respond to ambient GABA levels and context-dependent neuromodulators like steroids. We find that GC-specific deletion of δGABA_A (cerebellar [cb] δ knockout [KO]) decreases tonic inhibition, makes GCs hyperexcitable, and in turn, leads to differential activation of cb output regions as well as many cortical and subcortical brain areas involved in cognition, anxiety-like behaviors, and the stress response. Cb δ KO mice display deficits in many behaviors, but motor function is normal. Strikingly, δGABA_A deletion alters maternal behavior as well as spontaneous, stress-related, and social behaviors specifically in females. Our findings establish that δGABA_ARs enable the cerebellum to control diverse behaviors not previously associated with the cerebellum in a sex-dependent manner. These insights may contribute to a better understanding of the mechanisms that underlie behavioral abnormalities in psychiatric and neurodevelopmental disorders that display a gender bias.

Rudolph et al. show that deletion of the neuromodulator and hormone-sensitive δGABA_A receptor subunit from cerebellar granule cells results in anxiety-like behaviors and female-specific deficits in social behavior and maternal care. δGABA_A deletion is associated with hyperexcitability of the cerebellar input layer and altered activation of many stress-related brain regions.

Central Neurocircuits Regulating Food Intake in Response to Gut Inputs-Preclinical Evidence

The regulation of energy balance requires the complex integration of homeostatic and hedonic pathways, but sensory inputs from the gastrointestinal (GI) tract are increasingly recognized as playing critical roles. The stomach and small intestine relay sensory information to the central nervous system (CNS) via the sensory afferent vagus nerve. This vast volume of complex sensory information is received by neurons of the nucleus of the tractus solitarius (NTS) and is integrated with responses to circulating factors as well as descending inputs from the brainstem, midbrain, and forebrain nuclei involved in autonomic regulation. The integrated signal is relayed to the adjacent dorsal motor nucleus of the vagus (DMV), which supplies the motor output response via the efferent vagus nerve to regulate and modulate gastric motility, tone, secretion, and emptying, as well as intestinal motility and transit; the precise coordination of these responses is essential for the control of meal size, meal termination, and nutrient absorption. The interconnectivity of the NTS implies that many other CNS areas are capable of modulating vagal efferent output, emphasized by the many CNS disorders associated with dysregulated GI functions including feeding. This review will summarize the role of major CNS centers to gut-related inputs in the regulation of gastric function with specific reference to the regulation of food intake.

Lesion of the Fastigial Nucleus in Juvenile Rats Deteriorates Rat Behavior in Adulthood, Accompanied by Altered Neuronal Activity in the Medial Prefrontal Cortex

The cerebellar cognitive affective syndrome may result from various cerebellar injuries. Although it is not exactly known which anatomical structures are involved, the fastigial nucleus has been thought to play a pivotal role according to recent studies. Here we investigate whether bilateral fastigial nucleus lesions in juvenile rats affect cognitive-associative and limbic related functions in adulthood. Furthermore, potential effects on the neuronal activity in the medial prefrontal cortex (mPFC) and local field coherence with the sensorimotor cortex (SMCtx) were evaluated. The fastigial nucleus was lesioned bilaterally by thermocoagulation via stereotaxically inserted electrodes in 23-day old male Sprague Dawley rats. Naïve and sham-lesioned rats (electrodes inserted above the nucleus and no electrical current applied) served as controls. As adults, all groups were tested for cognitive-associative function, social behavior, and anxiety. Thereafter, electrophysiological recordings were obtained under urethane anesthesia. Finally, lesions and recording sites were histologically verified. Spatial learning in a radial maze test and learning in an operant learning paradigm was disturbed in rats with fastigial lesions. Furthermore, in the elevated plus maze anxiety was enhanced, whereas social behavior was not affected. Electrophysiological recordings showed enhanced local field coherence between mPFC and SMCtx across all frequency bands. Impaired cognitive and affective functions together with enhanced coherence between mPFC and SMCtx after bilateral fastigial nucleus lesions indicate that the fastigial nucleus contribute to the development of the cerebellar cognitive affective syndrome and associated motor behavior.

FAM19A1, a brain-enriched and metabolically responsive neurokine, regulates food intake patterns and mouse behaviors

Cytokines and chemokines play diverse roles in different organ systems. Family with sequence similarity 19, member A1-5 (FAM19A1-A5; also known as TAFA1-5) is a group of conserved chemokine-like proteins enriched in the CNS of mice and humans. Their functions are only beginning to emerge. Here, we show that the expression of Fam19a1-a5 in different mouse brain regions are induced or suppressed by unfed and refed states. The striking nutritional regulation of Fam19a family members in the brain suggests a potential central role in regulating metabolism. Using a knockout (KO) mouse model, we show that loss of FAM19A1 results in sexually dimorphic phenotypes. In male mice, FAM19A1 deficiency alters food intake patterns during the light and dark cycle. Fam19a1 KO mice are hyperactive, and locomotor hyperactivity is more pronounced in female KO mice. Behavior tests indicate that Fam19a1 KO female mice have reduced anxiety and sensitivity to pain. Spatial learning and exploration, however, is preserved in Fam19a1 KO mice. Altered behaviors are associated with elevated norepinephrine and dopamine turnover in the striatum. Our results establish an in vivo function of FAM19A1 and highlight central roles for this family of neurokines in modulating animal physiology and behavior.-Lei, X., Liu, L., Terrillion, C. E., Karuppagounder, S. S., Cisternas, P., Lay, M., Martinelli, D. C., Aja, S., Dong, X., Pletnikov, M. V., Wong, G. W. FAM19A1, a brain-enriched and metabolically responsive neurokine, regulates food intake patterns and mouse behaviors.

High-frequency focal repetitive cerebellar stimulation induces prolonged increases in human pharyngeal motor cortex excitability

KEY POINTS

Neurostimulation is a rapidly emerging approach to swallowing rehabilitation, but cerebellar stimulation has not been explored as a treatment. Such proposed therapies for post-stroke dysphagia have required confirmation of physiological effects and optimisation of parameters in healthy humans prior to translational progression into patient groups. There is strong evidence for a role of the cerebellum in swallowing physiology, but this relationship has been under-explored. Recently, single pulses of cerebellar magnetic stimulation have been shown to directly evoke responses from pharyngeal musculature and produce short-term enhancement of cortico-pharyngeal motor evoked potentials, suggesting the feasibility of a cerebellar approach to neurostimulation in the swallowing system. We therefore examined multiple parameters of repetitive cerebellar magnetic stimulation and have described the optimal settings to provoke longer-lasting changes in swallowing neurophysiology. Based on evidence from the post-stroke dysphagia neurostimulation literature, these changes may have a therapeutic potential for swallowing rehabilitation.

ABSTRACT

Brain neurostimulation has been shown to modulate cortical swallowing neurophysiology in post-stroke dysphagia with therapeutic effects which are critically dependent on the stimulation parameters. Cerebellar neurostimulation is, however, a novel, unexplored approach to modulation of swallowing pathways as a prelude to therapy for dysphagia. Here, we randomised healthy human subjects (n = 17) to receive one of five cerebellar repetitive TMS (rTMS) interventions (Sham, 1 Hz, 5 Hz, 10 Hz and 20 Hz) on separate visits to our laboratory. Additionally, a subset of subjects randomly received each of three different durations (50, 250, 500 pulses) of optimal frequency versus sham cerebellar rTMS. Prior to interventions subjects underwent MRI-guided single-pulse transcranial magnetic stimulation (TMS) to co-localise pharyngeal and thenar representation in the cortex and cerebellum (midline and hemispheric) before acquisition of baseline motor evoked potential (MEP) recordings from each site as a measure of excitability. Post-interventional MEPs were recorded for an hour and compared to sham using repeated measures ANOVA. Only 10 Hz cerebellar rTMS increased cortico-pharyngeal MEP amplitudes (mean bilateral increase 52%, P = 0.007) with effects lasting 30 min post-intervention with an optimal train length of 250 pulses (P = 0.019). These optimised parameters of cerebellar rTMS can produce sustained increases in corticobulbar excitability and may have clinical translation in future studies of neurogenic dysphagia.

Consensus paper: current views on the role of cerebellar interpositus nucleus in movement control and emotion

In the present paper, we examine the role of the cerebellar interpositus nucleus (IN) in motor and non-motor domains. Recent findings are considered, and we share the following conclusions: IN as part of the olivo-cortico-nuclear microcircuit is involved in providing powerful timing signals important in coordinating limb movements; IN could participate in the timing and performance of ongoing conditioned responses rather than the generation and/or initiation of such responses; IN is involved in the control of reflexive and voluntary movements in a task- and effector system-dependent fashion, including hand movements and associated upper limb adjustments, for quick effective actions; IN develops internal models for dynamic interactions of the motor system with the external environment for anticipatory control of movement; and IN plays a significant role in the modulation of autonomic and emotional functions.

Perinatal intermittent hypoxia alters γ-aminobutyric acid: a receptor levels in rat cerebellum

Perinatal hypoxia commonly causes brain injury in infants, but the time course and mechanisms underlying the preferential male injury are unclear. Intermittent hypoxia disturbs cerebellar γ-aminobutyric (GABA)-A receptor profiles during the perinatal period, possibly responding to transient excitatory processes associated with GABA(A) receptors. We examined whether hypoxic insults were particularly damaging to the male rodent cerebellum during a specific developmental time window. We evaluated cerebellar injury and GABA(A) receptor profiles following 5-h intermittent hypoxia (IH: 20.8% and 10.3% ambient oxygen, switched every 240s) or room-air control in groups of male and female rat pups on postnatal d 1-2, wk 1, or wk 3. The cerebella were harvested and compared between groups. The mRNA levels of GABA(A) receptors α6, normalized to a house-keeping gene GAPDH, and assessed using real-time reverse-transcriptase PCR assays were up-regulated by IH at wk 1, more extensively in male rats, with sex influencing the regulatory time-course. In contrast, GABA(A) α6 receptor protein expression levels, assessed using Western blot assays, reached a nadir at wk 1 in both male and female rats, possibly indicating involvement of a post-transcriptional mechanism. The extent of cerebellar damage and level of apoptosis, assessed by DNA fragmentation, were greatest in the wk 3 IH-exposed group. The findings suggest partial protection for female rats against early hypoxic insult in the cerebellum, and that down-regulation of GABA(A) receptors, rather than direct neural injury assessed by DNA fragmentation may modify cerebellar function, with potential later motor and other deficits.

Non-invasive magnetic stimulation of the human cerebellum facilitates cortico-bulbar projections in the swallowing motor system

BACKGROUND

Animal and human brain imaging studies suggest that the cerebellum plays an important role in the control of swallowing. In this study, we probed the interaction between cerebellar and pharyngeal motor cortical activity with transcranial magnetic stimulation (TMS) to determine if the cerebellum can modulate cortical swallowing motor circuitry.

METHODS

Healthy volunteers (n=16, eight men, mean age=32, range 19-57years) underwent TMS measurements of pharyngeal electromyography (EMG) recorded from a swallowed intraluminal catheter to assess cortical and cerebellar excitability. Subjects then underwent a paired pulse paradigm, where active or sham TMS conditioning pulses over the cerebellum and control sites were followed by suprathreshold TMS over the cortical pharyngeal area. Paired pulses were delivered at varying inter-stimulus intervals (ISIs) with the cortical response amplitudes being assessed.

KEY RESULTS

Stimulation of the cerebellum over its midline or hemispheres evoked distinct pharyngeal EMG responses. There was no difference in EMG amplitudes following cerebellar hemispheric or midline stimulation (mean 55.5±6.9 vs 42.8±5.9μV, P=0.08). In contrast, after cerebellar preconditioning, the cortically evoked responses underwent maximal facilitation at ISIs of 50-200ms (P<0.05), an effect not seen with sham or trigeminal nerve preconditioning.

CONCLUSIONS & INFERENCES

  Posterior fossa stimulation excites the cerebellum and evokes direct motor responses within the pharynx. When conditioned with TMS, the cerebellum strongly facilitates the cortical swallowing motor pathways. This finding suggests that the cerebellum exerts a modulatory effect on human swallowing and raises the possibility that excitatory neurostimulation of the cerebellum may be therapeutically useful in promoting recovery of dysphagia after neural damage.

A role for orexin in central vestibular motor control

The absence of orexin results in narcolepsy-cataplexy. While the function of the central orexinergic system in sleep regulation has been well studied, the role of orexin in motor control is largely unknown. Here, we show that orexin-A acts via OX(1) and OX(2) receptors to directly depolarize neurons in the rat lateral vestibular nucleus (LVN), a subcortical motor center, and enhance their sensitivity. A dual ionic mechanism involving both Na+-Ca²+ exchangers and inward rectifier K+ channels underlies these effects. Furthermore, orexin-A regulates central vestibular-mediated posture, motor balance and negative geotaxis. Orexin is critical when an animal is facing a major motor challenge as opposed to during rest and general movements. Therefore, orexin participates not only in sleep and emotion (nonsomatic) but also in motor (somatic) regulation, suggesting that the central orexinergic system plays an important role in somatic-nonsomatic integration. These findings may account for why the absence of orexin results in narcolepsy-cataplexy.

Defining the role of cholecystokinin in the lipid-induced human brain activation matrix

BACKGROUND & AIMS

In human beings, as in most vertebrates, the release of the intestinal peptide cholecystokinin (CCK) by ingested food plays a major role both in digestion and the regulation of further food intake, but the changes in brain function and their underlying activation mechanisms remain unknown. Our aim was to explore, using a novel physiologic magnetic resonance imaging approach, the temporospatial brain activation matrix, in response to ingestion of a lipid meal and, by use of a CCK-1 receptor antagonist, to define the role of CCK in this activation.

METHODS

We studied, in 19 healthy subjects, the brain activation responses to ingested lipid (dodecanoic acid) or saline (control) with magnetic resonance imaging. Gallbladder volume, plasma CCK levels, and subjective hunger and fullness scores were also recorded. The experiment was then repeated, with and without prior administration of the CCK-1 receptor antagonist dexloxiglumide (600 mg orally) with a controlled, randomized order, latin-square design.

RESULTS

Ingested lipid activated bilaterally a matrix of brain areas, particularly the brain stem, pons, hypothalamus, and also cerebellum and motor cortical areas. These activations were abolished by dexloxiglumide, indicating a CCK-mediated pathway, independent of any nutrient-associated awareness cues.

CONCLUSION

The identification of these activations now defines the lipid-activated brain matrix and provides a means by which the gut-derived homeostatic mechanisms of food regulation can be distinguished from secondary sensory and hedonic cues, thereby providing a new approach to exploring aberrant human gastrointestinal responses and eating behavior.

The cerebellum harbors a circadian oscillator involved in food anticipation

The cerebellum participates in motor coordination as well as in numerous cerebral processes, including temporal discrimination. Animals can predict daily timing of food availability, as manifested by food-anticipatory activity under restricted feeding. By studying ex vivo clock gene expression by in situ hybridization and recording in vitro Per1-luciferase bioluminescence, we report that the cerebellum contains a circadian oscillator sensitive to feeding cues (i.e., whose clock gene oscillations are shifted in response to restricted feeding). Food-anticipatory activity was markedly reduced in mice injected intracerebroventricularly with an immunotoxin that depletes Purkinje cells (i.e., OX7-saporin). Mice bearing the hotfoot mutation (i.e., Grid2(ho/ho)) have impaired cerebellar circuitry and mild ataxic phenotype. Grid2(ho/ho) mice fed ad libitum showed regular behavioral rhythms and day-night variations of clock gene expression in the hypothalamus and cerebellum. When challenged with restricted feeding, however, Grid2(ho/ho) mice did not show any food-anticipatory rhythms, nor timed feeding-induced changes in cerebellar clock gene expression. In hypothalamic arcuate and dorsomedial nuclei, however, shifts in Per1 expression in response to restricted feeding were similar in cerebellar mutant and wild-type mice. Furthermore, plasma corticosterone and metabolites before mealtime did not differ between cerebellar mutant and wild-type mice. Together, these data define a role for the cerebellum in the circadian timing network and indicate that the cerebellar oscillator is required for anticipation of mealtime.

Association of body mass and brain activation during gastric distention: implications for obesity

Background

Gastric distention (GD), as it occurs during meal ingestion, signals a full stomach and it is one of the key mechanisms controlling food intake. Previous studies on GD showed lower activation of the amygdala for subjects with higher body mass index (BMI). Since obese subjects have dopaminergic deficits that correlate negatively with BMI and the amygdala is innervated by dopamine neurons, we hypothesized that BMI would correlate negatively with activation not just in the amygdala but also in other dopaminergic brain regions (midbrain and hypothalamus).

Methodology/Principal Findings

We used functional magnetic resonance imaging (fMRI) to evaluate brain activation during GD in 24 healthy subjects with BMI range of 20–39 kg/m². Using multiple regression and cross-correlation analyses based on a family-wise error corrected threshold P = 0.05, we show that during slow GD to maximum volumes of 500 ml and 700 ml subjects with increased BMI had increased activation in cerebellum and left posterior insula, and decreased activation of dopaminergic (amygdala, midbrain, hypothalamus, thalamus) and serotonergic (pons) brain regions and anterior insula, regions that were functionally interconnected with one another.

Conclusions

The negative correlation between BMI and BOLD responses to gastric distention in dopaminergic (midbrain, hypothalamus, amygdala, thalamus) and serotonergic (pons) brain regions is consistent with disruption of dopaminergic and serotonergic signaling in obesity. In contrast the positive correlation between BMI and BOLD responses in posterior insula and cerebellum suggests an opposing mechanism that promotes food intake in obese subjects that may underlie their ability to consume at once large food volumes despite increasing gastric distention.

Analysis of cerebellar function in Ube3a-deficient mice reveals novel genotype-specific behaviors

Angelman syndrome (AS) is a childhood-onset neurogenetic disorder characterized by functionally severe developmental delay with mental retardation, deficits in expressive language, ataxia, appendicular action tremors and unique behaviors such as inappropriate laughter and stimulus-sensitive hyperexcitibility. Most cases of AS are caused by mutations which disrupt expression of maternal UBE3A. Although some progress has been made in understanding hippocampal-related memory and learning aspects of the disorder using Ube3a deficient mice, the numerous motoric abnormalities associated with AS (ataxia, action tremor, dysarthria, dysphagia, sialorrhea and excessive chewing/mouthing behaviors) have not been fully explored with mouse models. Here we use a novel quantifiable analysis of fluid consumption and licking behavior along with a battery of motor tests to examine cerebellar and other motor system defects in Ube3a deficient mice. Mice with a maternally inherited Ube3a deficiency (Ube3a(m-/p+)) show defects in fluid consumption behavior which are different from Ube3a(m-/p-) mice. The rhythm of fluid licking and number of licks per visit were significantly different among the three groups (m-/p-, m-/p+, m+/p+) and indicate that not only was fluid consumption dependent on Ube3a expression in the cerebellum, but may also depend on low levels of Ube3a expression in other brain regions. Additional neurological testing revealed defects in both Ube3a(m-/p+) and Ube3a(m-/p-) mice in rope climbing, grip strength, gait and a raised-beam task. Long-term observation of fluid consumption behavior is the first phenotype reported that differentiates between mice with a maternal loss of function versus complete loss of Ube3a in the brain. The neuronal and molecular mechanisms underlying mouse fluid consumption defects specifically associated with maternally inherited Ube3a deficiency may reveal important new insights into the pathobiology of AS in humans.

The cerebellum in feeding control: possible function and mechanism

Accumulating anatomical, functional, and behavioral studies reveal that the cerebellum is involved in the regulation of various visceral functions including feeding control. Cerebellar lesions may induce alterations in feeding behavior and decreases in body weight. Although the exact mechanisms underlying the cerebellar regulation of food intake is still unclear, a series of studies have demonstrated that there are neural pathways directly and/or indirectly connecting the cerebellum with several important centers for feeding control, such as the hypothalamus. Electrophysiological data suggest that via the direct cerebellohypothalamic projections, the cerebellar outputs may reach, converge, and be integrated with some critical feeding signals including gastric vagal afferents, CCK, leptin, and glycemia on single hypothalamic neurons. Furthermore, recent functional imaging studies provide substantial evidences that hunger, satiation, and thirst are accompanied with a cerebellar activation. Here we describe that the cerebellum may be much more than a movement coordinator and actively participate in feeding control, i.e., it may act as an essential node linking somatic and visceral systems and help to generate an integrated and coordinated somatic-visceral response in feeding behavior.

Dorsomedial hypothalamic nucleus neurons integrate important peripheral feeding-related signals in rats

Several studies have implicated the dorsomedial hypothalamic nucleus (DMN) in regulation of feeding behavior and body weight, but clear mechanisms by which it controls food intake are not well understood. We report the results of the present study, which showed that the DMN receives important peripheral short- and long-term feeding-related afferent signals, including gastric vagal, glycemia, and cholecystokinin (CCK) inputs, as well as from leptin, an adipostatic signal that forcefully inhibits food intake and increases metabolic rate. Among the 279 DMN neurons recorded, 173 (62.0%) responded to stimulation of gastric vagal nerves. Also, of the 123 DMN neurons responsive to gastric vagal stimulation that were tested with the administration of intravenous glucose, 75 (61.0%) were identified as being glycemia sensitive. Moreover, it is noteworthy that of the 23 DMN neurons that responded to both gastric vagal and intravenous glucose stimulation, most (19 of 23, 82.6%) were sensitive to circulating leptin, and some neurons (n = 7) were also responsive to systemic CCK, suggesting that gastric vagal, glycemic, CCK, and leptin inputs converge on single DMN neurons. Furthermore, synergistic interactions between leptin and glucose on single DMN neurons were observed (n = 6). These results demonstrate that those important peripheral feeding-related gastric vagal, glycemic, CCK and leptin signals not only reach the DMN but also interact on single DMN neurons, suggesting that the DMN may not just function as a relay station, but independently integrate the short-term and long-term feeding-associated information and actively participate in the direct regulation of feeding behavior.