Long-Term Recording of Reticulo-Rumen Myoelectrical Activity in Sheep by a Telemetry Method

The reticulum and rumen are considered a single functional unit (the reticulo-rumen) with regards to myoelectrical and contractile activities. The specialized contractions of the reticulo-rumen provide constant mixing of partially digested material (cycle A), its flow into the omasum during eructation (cycle B), and regurgitation-rumination (cycle C). This study aimed to investigate the feasibility of electromyography (EMG) registered by a long-term telemetry method for assessment of the basic reticulo-rumen myoelectrical activity in sheep, to develop the effective recognition of the reticulo-rumen cycles at rest with no food stimulation, and to investigate the relationship between cycles A, B, and C in such basic conditions. The experiment was carried out on nine ewes. Myoelectric activity of the rumen, reticulum, and abomasum was recorded by the combination of three silver bipolar electrodes and a 3-channel transmitter implant. The myoelectrical activity registered successfully in the reticulum and rumen was determined as three characteristic patterns of cycles A, B, and C. The percentage of each type of cycle changed at different intervals from equally cycles A (43–50%) and B (50–56%), occurring when cycle C was not observed to the domination of cycle C (57–73%) with a decrease of cycles A (6–14%) and B (20–28%). The long-term EMG telemetry registration is feasible in the assessment of the reticulo-rumen myoelectrical activity in sheep.

Inhibition of food craving is a metabolically active process in the brain in obese men

Objective Obesity is associated with impaired inhibitory control over food intake. We hypothesized that the neural circuitry underlying inhibition of food craving would be impaired in obesity. Here we assessed whether obese men show altered brain responses during attempted cognitive inhibition of craving when exposed to food cues. Methods Sixteen obese men (32 ± 8.7 years old, BMI = 38.6 ± 7.2) were compared with 11 age-matched non-obese men (BMI 24.2 ± 2.5) using PET and FDG. Brain glucose metabolism was evaluated in a food deprived state: no food stimulation, food stimulation with no inhibition (NI), and food stimulation with attempted inhibition (AI), each on a separate day. Individualized favorite food items were presented prior to and after FDG injection for 40 min. For AI, participants were asked to attempt to inhibit their desire for the food presented. Self-reports for hunger and food desire were recorded. Results Food stimulation compared with no stimulation increased glucose metabolism in inferior and superior frontal gyrus, default mode network and cerebellum, in both groups. For both groups, AI compared with NI-suppressed metabolism in right subgenual anterior cingulate, orbitofrontal areas, bilateral insula, and temporal gyri. There was a stimulation-by-group interaction effect in obese (but not in non-obese) men showing increased metabolism in pregenual anterior cingulate cortex (pgACC) and caudate during AI relative to NI. Changes in the food desire from NI to AI correlated negatively with changes in metabolism in pgACC/caudate in obese but not in non-obese men. Conclusions Obese men showed higher activation in pgACC/caudate, which are regions involved with self-regulation and emotion/reward during AI. Behavioral associations suggest that successful AI is an active process requiring more energy in obese but not in non-obese men. The additional required effort to increase cognitive control in response to food stimulation in obese compared with non-obese men may contribute to their uncontrolled eating behavior.

An unusual presentation of post gastric bypass hypoglycemia with both postprandial and fasting hypoglycemia

Summary There has been an increasing awareness of post gastric bypass hypoglycemia (PGBH). Histopathologic findings from such patients who underwent partial/total pancreatomy, however, can vary widely from minimal changes to classic nesidioblastosis, making the pathologic diagnosis challenging. PGBH typically presents as postprandial hypoglycemia, as opposed to insulinoma, which presents as fasting hypoglycemia. Herein, we describe an unusual case of a patient with PGBH who initially presented with postprandial hypoglycemia three years after surgery, but later developed fasting hyperinsulinemic hypoglycemia as the disease progressed. Our hypothesis for this phenomenon is that this disease is progressive, and later in its course, the insulin release becomes dissociated from food stimulation and is increased at baseline. Future studies are needed to investigate the prevalence as well as etiology of this progression from postprandial to fasting hypoglycemia. Learning points: There has been an increasing awareness of post gastric bypass hypoglycemia (PGBH). Histopathologically, PGBH can vary from minimal changes to nesidioblastosis. Although uncommon, patients with PGBH after Roux-en-Y gastric bypass may present with both postprandial and fasting hyperinsulinemic hypoglycemia as disease progresses. Our hypothesis for this phenomenon is that the insulin release becomes dissociated from food stimulation and is increased at baseline with disease progression.

Snack food as a modulator of human resting-state functional connectivity

ObjectiveTo elucidate the mechanisms of how snack foods may induce non-homeostatic food intake, we used resting state functional magnetic resonance imaging (fMRI), as resting state networks can individually adapt to experience after short time exposures. In addition, we used graph theoretical analysis together with machine learning techniques (support vector machine) to identifying biomarkers that can categorize between high-caloric (potato chips) vs. low-caloric (zucchini) food stimulation.MethodsSeventeen healthy human subjects with body mass index (BMI) 19 to 27 underwent 2 different fMRI sessions where an initial resting state scan was acquired, followed by visual presentation of different images of potato chips and zucchini. There was then a 5-minute pause to ingest food (day 1=potato chips, day 3=zucchini), followed by a second resting state scan. fMRI data were further analyzed using graph theory analysis and support vector machine techniques.ResultsPotato chips vs. zucchini stimulation led to significant connectivity changes. The support vector machine was able to accurately categorize the 2 types of food stimuli with 100% accuracy. Visual, auditory, and somatosensory structures, as well as thalamus, insula, and basal ganglia were found to be important for food classification. After potato chips consumption, the BMI was associated with the path length and degree in nucleus accumbens, middle temporal gyrus, and thalamus.ConclusionThe results suggest that high vs. low caloric food stimulation in healthy individuals can induce significant changes in resting state networks. These changes can be detected using graph theory measures in conjunction with support vector machine. Additionally, we found that the BMI affects the response of the nucleus accumbens when high caloric food is consumed.