|Friday, April 15th|
4:00 PM - 4:20 PM
Although alcohol is widely researched for its psychological and physiological effects on performance, past research has focused on aerobic modes. Therefore, we aimed to determine the effects of acute alcohol ingestion on tests of anaerobic performance. Twenty five subjects (13 female, 12 male, 22 ± 3 yrs, 173 ± 12 cm, 70 ± 17 kg, VO2 max 45 ± 8 ml/kg/min) were tested in a randomized crossover design, once consuming a placebo (6.4 ml/kg orange juice for females and 7.9 ml /kg for males) and once consuming 80 proof alcohol (2.6 ml/kg alcohol + 5.3 ml/kg orange juice for males and 2.1 ml/kg alcohol + 4.3 ml/kg juice for females) to achieve a 0.06% blood alcohol content as measured with a breathalyzer. Drinks were administered at 0, 15, and 30 minutes. Tests included a one repetition maximum (RM) bench press, vertical jump, two-minute crunches, and 30 second Wingate. Results indicated a significant decrease with alcohol consumption vs. placebo in average mean power (539 ± 168 vs. 556 ± 179 watts, alcohol and placebo, respectively, p<0.01) as well as average minimum power (384 ± 129 and 405 ± 131 watts, alcohol and placebo, respectively, p<0.01) during the Wingate. There was no difference between trials in the bench press, vertical jump, crunches, or Wingate peak power. These data suggest short duration (<15 seconds) or low intensity (i.e. crunches) activities are less influenced by alcohol than sustained high intensity activities. Further research is needed to elucidate the effect of alcohol on sustained anaerobic power.
4:20 PM - 4:40 PM
We investigated the development of the medial nucleus of the trapezoid body (MNTB) and the lateral superior olive (LSO), two brainstem nuclei involved sound localization. Many physical and chemical cellular interactions occur in LSO and MNTB neurons during early development. Although the development of these nuclei is poorly understood, dynamic changes occur in a subset of inhibitory neurons in LSO and MNTB. Although these inhibitory neurons use the neurotransmitters GABA and glycine and are essential to the proper functioning of the auditory system, they have not yet been systematically visualized during development in auditory brainstem nuclei. We tracked the development of inhibitory neuron subtypes in LSO and MNTB using transgenic mice in which yellow fluorescent protein (YFP) or green fluorescent protein (GFP) is driven by promoters for the calcium binding protein parvalbumin (PV) or the GABA synthesizing enzyme GAD65, respectively. Using antibody labeling and fluorescent microscopy, we compared the number and distribution of fluorescent cells in LSO and MNTB prior to, during, and after the onset of hearing for each strain of mouse. Although the transition from a GABAergic to glycinergic phenotypes has been described physiologically, this is the first study that uses transgenic mice to visualize this transition. The inhibitory neurotransmitter GABA plays an important role before the onset of hearing, but glycine is important after the onset of hearing. Investigating these inhibitory neurons increases our knowledge of sound processing in the auditory system.
4:40 PM - 5:00 PM
The Archean Rocks of Yellowstone National Park appear to be similar to that of the Precambrian terranes found in neighboring mountain ranges, such as the Beartooths. These Precambrian Archean rocks were sampled last summer from along the Yellowstone River, from Bear Creek near Gardiner, MT to Hellroaring Creek and north of Tower Junction within northern Yellowstone National Park in order to determine if these terranes are from the same depositional environment. The samples collected are representative of shallow regional metamorphism, and are composed primarily of biotite schists containing diagnostic metamorphic assemblages that have been termed the Jardine Metasedimentary Sequence (JMS). The metamorphic grade increases slightly across the study area, which was established based on petrology of the samples. Chlorite-biotite assemblages are more prevalent in biotite schists in the west and transition into garnet-andalusite-chlorite-biotite and garnet-staurolite-biotite in the east. Staurolite occurs in a few of the samples in varying textures. A few of the samples with varying assemblages were analyzed with an electron microprobe obtaining mineral composition data from five samples that were then inputted into the program Thermocalc to calculate average pressures and temperatures (P-T) of metamorphism across the area. Small variations in P-T were observed, ranging from 572-608° C and 4.1-5.8 kbar. The JMS along with adjacent rocks in the Garnet Hill area to the east are of anomalously low metamorphic grade compared to other rocks of the northern Wyoming Province, and the JMS may represent a separate, distinctive unit that is allochthonous within this northern part of YNP.