A Survey of Energy Drink Consumption Patterns Among College Students at a Mostly Hispanic University.

Background: The purpose of this study was to determine energy drink (ED) consumption patterns among Hispanic college students. We measured the prevalence and frequency of ED consumption according to gender, degree programs, and specific university-related and social situations. In addition, we assessed the frequency of consumption of EDs mixed with alcoholic beverages. Methods: A total of 508 college students from the University of Puerto Rico, the largest Hispanic institution of higher education statewide, completed an online questionnaire. Results: Twenty-one percent of participants reported consuming EDs with the majority consuming EDs either occasionally (every 2-3 months) or at least once or twice a month. Men were found to be more likely to consume EDs than women. Undergraduate students were found less likely to consume EDs than graduate students. Most students consumed EDs while studying and during social activities. More than one-third of participants that consume EDs admitted mixing them with an alcoholic beverage. Graduate students were found to consume EDs mixed with alcohol more often. Conclusions: The majority of students consumed EDs occasionally and while studying. Most side effects reported after consuming EDs were similar to previous findings. The higher consumption of EDs and of EDs mixed with alcohol by students in graduate programs could be explained by a higher and more complex study load requiring longer periods of wakefulness and concentration. Future studies looking at the consumption patterns of EDs in more competitive graduate programs such as medical and/or dentistry school should be considered.

Correlations in ion channel mRNA in rhythmically active neurons.

BACKGROUND: To what extent do identified neurons from different animals vary in their expression of ion channel genes? In neurons of the same type, is ion channel expression highly variable and/or is there any relationship between ion channel expression that is conserved? METHODOLOGY/PRINCIPAL FINDINGS: To address these questions we measured ion channel mRNA in large cells (LCs) of the crab cardiac ganglion. We cloned a calcium channel, caco, and a potassium channel, shaker. Using single-cell quantitative PCR, we measured levels of mRNA for these and 6 other different ion channels in cardiac ganglion LCs. Across the population of LCs we measured 3-9 fold ranges of mRNA levels, and we found correlations in the expression of many pairs of conductances CONCLUSIONS/SIGNIFICANCE: In previous measurements from the crab stomatogastric ganglion (STG), ion channel expression was variable, but many pairs of channels had correlated expression. However, each STG cell type had a unique combination of ion channel correlations. Our findings from the crab cardiac ganglion are similar, but the correlations in the LCs are different from those in STG neurons, supporting the idea that such correlations could be markers of cell identity or activity.

Plasticity of addiction: a mesolimbic dopamine short-circuit?

The development of drug addiction progresses along a continuum from acute drug use to compulsive use and drug seeking behavior. Many researchers have focused on identifying the physiological mechanisms involved in drug addiction in order to develop effective pharmacotherapies. Neuroplasticity, the putative mechanism underlying learning and memory, is modified by drugs of abuse and may contribute to the development of the eventual addicted state. Innovative treatments directly targeting these drug-induced changes in brain reward components and circuits may be efficacious in reducing drug use and relapse.

Multiple modulators act on the cardiac ganglion of the crab, Cancer borealis.

Neuromodulators can change the output of neural circuits. The crustacean cardiac ganglion (CG) drives the contractions of the heart. The CG is a direct target for neurohormones that are released from the pericardial organs and other neuroendocrine sites. In this study, we have characterized for the first time the physiological actions of the peptides red pigment concentrating hormone (RPCH), Cancer borealis tachykinin-related peptide Ia (CabTRP Ia) and allatostatin III type A (AST-3) on the isolated CG of the crab, Cancer borealis. RPCH and CabTRP Ia excited the CG while AST-3 strongly inhibited its motor output. We also studied the actions of other peptides and small molecule transmitters known to be present in C. borealis. Dopamine, serotonin, proctolin, crustacean cardioactive peptide (CCAP), a number of extended FLRFamide peptides, and cholinergic agonists increased the activity of the CG, GABA inhibited the CG, while other substances had little or no significant effect on the CG motor pattern. These results demonstrate, in one species, that the CG is multiply modulated. We suggest that multiple modulators may be important to regulate and coordinate the activity of the heart and other organs in response to external stimuli or the endogenous physiological state.

Mass spectrometric characterization and physiological actions of GAHKNYLRFamide, a novel FMRFamide-like peptide from crabs of the genus Cancer.

The stomatogastric ganglion (STG) and the cardiac ganglion (CG) of decapod crustaceans are modulated by neuroactive substances released locally and by circulating hormones released from neuroendocrine structures including the pericardial organs (POs). Using nanoscale liquid chromatography electrospray ionization quadrupole-time-of-flight tandem mass spectrometry and direct tissue matrix-assisted laser desorption/ionization Fourier transform mass spectrometry we have identified and sequenced a novel neuropeptide, GAHKNYLRFamide (previously misassigned as KHKNYLRFamide in a study that did not employ peptide derivatization), from the POs and/or the stomatogastric nervous system (STNS) of the crabs, Cancer borealis, Cancer productus and Cancer magister. In C. borealis, exogenous application of GAHKNYLRFamide increased the burst frequency and number of spikes per burst of the isolated CG and re-initiated bursting activity in non-bursting ganglia, effects also elicited by the FMRFamide-like peptides (FLPs) SDRNFLRFamide and TNRNFLRFamide. In the intact STNS (which contains the STG), exogenous application of GAHKNYLRFamide increased the frequency of the pyloric rhythm and activated the gastric mill rhythm, effects also similar to those elicited by SDRNFLRFamide and TNRNFLRFamide. FLP-like immunoreactivity in the POs and the STNS was abolished by pre-adsorption with the synthetic GAHKNYLRFamide. Different members of the FLP family exhibited differential degradation in the presence of extracellular peptidases. Taken collectively, the amino acid sequence of GAHKNYLRFamide, the blocking of FLP-like immunostaining, and its physiological effects on the CG and STNS suggest that this peptide is a novel member of the FLP superfamily.

Nitric oxide inhibits the rate and strength of cardiac contractions in the lobster Homarus americanus by acting on the cardiac ganglion.

The lobster heart is synaptically driven by the cardiac ganglion, a spontaneously bursting neural network residing within the cardiac lumen. Here, we present evidence that nitric oxide (NO) plays an inhibitory role in lobster cardiac physiology. (1) NO decreases heartbeat frequency and amplitude. Decreased frequency is a direct consequence of a decreased ganglionic burst rate. Decreased amplitude is an indirect consequence of decreased burst frequency, attributable to the highly facilitating nature of the synapses between cardiac ganglion neurons and muscle fibers (although, during prolonged exposure to NO, amplitude recovers to the original level by a frequency-independent adaptation mechanism). NO does not alter burst duration, spikes per burst, heart muscle contractility, or amplitudes of synaptic potentials evoked by stimulating postganglionic motor nerves. Thus, NO acts on the ganglion, but not on heart muscle. (2) Two observations suggest that NO is produced within the lobster heart. First, immunoblot analysis shows that nitric oxide synthase (NOS) is strongly expressed in heart muscle relative to other muscles. Second, L-nitroarginine (L-NA), an NOS inhibitor, increases the rate of the heartbeat (opposite to the effects of NO). In contrast, the isolated ganglion is insensitive to L-NA, suggesting that heart muscle (but not the ganglion) produces endogenous NO. Basal heart rate varies from animal to animal, and L-NA has the greatest effect on the slowest hearts, presumably because these hearts are producing the most NO. Thus, because the musculature is a site of NOS expression, whereas the ganglion is the only intracardiac target of NO, we hypothesize that NO serves as an inhibitory retrograde transmitter.

[Bulimic and depressive symptomatology in Puerto Rican adolescents]. / Sintomatología bulímica y depresiva en adolescentes puertorriqueños/as.

Bulimia nervosa and depression have been identified as frequent mental health problems among adolescents. Bulimia nervosa, an eating disorder has been associated with depression especially among female population. The literature has established a high comorbidity between these disorders. Although depression was initially conceptualized as an adult disorder, recent research evidenced this disorder among adolescents. For this study, it was hypothesized that participants who presented bulimic symptomatology were going to present a higher depressive symptomatology than those who had no bulimic symptoms. The Bulimia Test (Bulit) and the Children's Depression Inventory (CDI) were administered to 309 students from a private high school in San Juan, Puerto Rico. Correlation analyses and group comparisons were performed to investigate the relationship between bulimia nervosa and depression among participants. As hypothesized, a significant correlation (p < .01) was found between depression and bulimia nervosa symptomatology. Females showed a higher average of bulimic symptomatology than males. Early identification for treatments with bulimia and depression would be helpful in preventing future problems in later adulthood. Implications of this study are discussed.