Evaluation of bilateral gastric electrical stimulation to improve energy balance regulation in male Sprague-Dawley rats consuming a 45% high-fat diet

Study Purpose: Electrical stimulation of the stomach has typically been limited to the ventral wall of the organ and found to be relatively ineffective at improving energy balance regulation in adult male Sprague-Dawley rats. Unilateral stimulation of the ventral stomach wall ignores the fact that the vagus nerve innervates both the ventral and the dorsal walls of the stomach. Thus, taking into account the bilateral innervation of the forestomach by the vagus nerve, we implanted two patch electrodes, one at each site on the ventral and the dorsal walls of the stomach that is known to contain the highest density of overlapping vagal terminals located in the circular and longitudinal muscle (i.e., intramuscular arrays). Consumption of a 45% high-fat maintenance diet while the stomach was stimulated both bilaterally and unilaterally was recorded to determine if there was an improvement in energy balance regulation to this high-fat diet challenge.

Data Collection: Microstructural analysis of food intake as a behavioral endpoint to determine the effect of bilateral electrical stimulation of the forestomach on the consumption of a 45% high fat diet by male Sprague-Dawley rats.

Primary Conclusion: The shams' body weight and food intake did not differ from those of the stimulated rats under the three conditions tested (i.e., bilateral and unilateral stimulation of the stomach walls). Both groups had similar blood glucose levels at the completion of the study.

Curator's Notes

Experimental Design: Eight male Sprague-Dawley rats, each with two patch electrodes implanted on the serosal wall of the forestomach (one on the ventral wall of the forestomach and a second on the dorsal wall of the forestomach), were stimulated continuously for 14-17 days under three different conditions (bilateral stimulation of both walls of the forestomach or unilateral stimulation of either the ventral or the dorsal forestomach wall, respectively). The following stimulation parameter was used: 0.3mA, 0.2ms, 10Hz, 20s On, 40s Off. Six additional rats with implanted patch electrodes served as unstimulated shams. Both groups had ad lib access to a 45% high-fat diet (Research Diets; D12451; 45 kcal% fat) starting three months prior to surgical implantation of the patch electrodes and were then maintained on the same high-fat diet throughout the experiment. Following completion of the study, seven of the eight previously stimulated rats (one was dropped because of failure of its back mount) were further stimulated bilaterally for 14 days (stimulation parameter: 0.9mA, 0.2ms, 10Hz, 20s On, 40s Off). Ad lib intake of the 45% high-fat diet was continuously monitored for each individually housed rat throughout the study using the BioDAQ automated intake monitoring system from Research Diets.

Completeness: This dataset is complete

Subjects & Samples: Adult male (n=14) Sprague-Dawley rats (RRID: RGD_737903) were used in this study.

Primary vs. derivative data: The primary data consist of a recording of feeding behavior for individual subjects collected over the course of the experiment in a spreadsheet XLSX format. The derivative folder contains the transformed primary data located in the primary folder. The data consist of summative feeding data in a multiworkbook spreadsheet and the endpoint measurement of body fat and blood glucose levels. Thumbnail graphs of the transformed data are included. As back mount failure occurred starting six to eight weeks post-surgery, only the data from experimental weeks completed (i.e., the full seven days) prior to failure was used in the derivative excel files and companion thumbnails. Within pool-1 is the data for individual subjects in spreadsheet XLSX format.