1. Abstract Leptin signals are important to the maintenance of somatotrope functions. When exon 17 of the leptin receptor gene is deleted selectively in somatotropes by Cre-loxP technology, mice express lower serum and pituitary levels of growth hormone (GH) and develop adult onset obesity by 6 months of age (Childs et al, 2011). In order to determine factors causing the obesity, 3-5 month old deletion mutant mice and littermate controls were studied in an Oxymax Comprehensive Lab Animal Monitoring System (CLAMS, Columbus Instruments). The automated system did not detect differences in the amount of food consumed. Deletion mutant females expended less energy than controls, showing significant (p<0.01) reductions in heat production, from an average of 0.53±0.04 kcal/h (controls n=13) to 0.47±0.05 kcal/h (mutants, n=11). This correlated well with a significant (p=0.02) reduction in activity (detected by counts of infrared beam breaks in the X-Y axis) from 790.6±38 (controls) to 633.5±47 (mutants) and in rearing or jumping (# beam breaks, Z axis) from 628±29 (controls) to 353±12 (mutants). When activity counts were used to define sleep epochs, deletion mutant and control females were not different. In contrast, deletion mutant males showed a significant (p=0.017) reduction in the overall percent of time sleeping. Control males (n=11) spent an average of 30 ± 3% of their time sleeping compared with deletion mutants (n=8), which slept 16.5±1.5% of the time. Analysis of the activity levels during the 14 h sleep phase (light) showed that mutant males were not as active as controls exhibiting 468±65 ambulatory and 129±26 rearing counts compared with 552±73 ambulatory and 168±32 rearing counts in the controls (p<0.05). During the dark phase, the average activity counts from mutant and control males were similar. These studies show sex differences in behaviors that may contribute to the obesity seen in these deletion mutants by 6 months of age. Food intake is normal, which correlates with their normal serum leptin and hypothalamic leptin receptors. Mutant females expended less energy and showed reduced ambulatory or rearing activity during both light and dark cycles. Males spent less time sleeping, but were less active during the light phase. These studies show the importance of leptin signaling to promote normal levels of GH, which may establish normal sleep patterns (in males) and activity levels in both sexes. All of these factors are known to prevent obesity. Supported by NIH NICHD R01 HD059056 and Core facilities funded by NCRR P20 RR020146 Core A and P30 NS047546. Introduction We recently reported that selective deletion of the signaling component of the leptin receptor (Lepr exon 17) in somatotropes reduced the number of immunolabeled growth hormone cells and serum GH, causing adult onset obesity (Childs et al, Endocrinology 2011 Jan;152(1):69- 81). Method Why are the animals getting fat? To determine metabolic or behavioral factors contributing to the obesity of these mutants, we monitored 4 groups of male or female mutant and littermate control mice in a Comprehensive Lab Animal Monitoring System (CLAMS), which records:  Gas exchange and heat.  Feeding  Infrared lights to detect X or Z activity.  Activity is an indirect detector of sleep. Mice were studied at 3-4.5 months of age, before the onset of obesity (1). Results Deletion mutant mice are not hyperphagic CLAMS  Detected number of feeding events  Weighed food at each event to detect amount eaten  Reported total grams of food eaten. n=20 controls, 16 mutants; P=0.688n=14 controls, 16 mutants; P=0.972 Time in CLAMS was 72 hours, with and without 48 h acclimation. Acclimation did not alter the overall pattern of differences between the mutants and Littermate controls. Mutant male and female mice ate as much food at each feeding bout and overall at did controls. Deletion mutant female mice are not as active as controls CLAMS detects X and Z activity with infrared sensors, providing counts of number of infrared beam breaks. Female mice lacking Lepr exon 17 in somatotropes were less active in every way than littermate controls. Heat output was also less. Heat = CV × VO2 CV = 3. 815 + 1. 232 × RER n=15 controls, 16 mutants Mutant male mice are equally active, but have less heat output Lack of sleep and activity may contribute to the adult-onset obesity in deletion mutant mice lacking leptin receptors in pituitary somatotropes. Akhter, N; Odle, A; Cozart, M; Syed, M; Haney, A and Childs, G Mutant males spend less time sleeping Activity counts detect and record consecutive sleep epochs=60 sec bouts of no activity. Males, but not females, appear to spend less time sleeping. Cage has a cubby that is appealing to mice especially during sleep cycle Changes in respiratory exchange ratios (RER) The respiratory exchange ratio (RER) is the ratio between the carbon dioxide production and the oxygen consumption. As it is a ratio, it does not have a unit. RER values indicate that deletion mutants burn more carbohydrates than fat, whereas the controls burn a mixture. RER = VCO2/VO2 Conclusions: Contributing factors that may cause obesity  Females are less active.  Both sexes have lower energy output (Heat).  Males sleep less than controls  Both sexes may have problems with fat burning due to low serum GH ( Childs et al, Endocrinology 2011 Jan;152(1):69-81). Supported by NIH NICHD R01 HD059056 and Core facilities funded by NCRR P20 RR020146 Core A and P30 NS047546.

2. Methods Support Conclusion Introduction Abstract Gamma Band Single Cell and Population Activity in the Subcoeruleus Nucleus - Effects of Carbachol J. Hyde, C. Simon, N. Kezunovic, M. Ye, D. Heister, K. Smith, E. Garcia-Rill Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205