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Full-Text Articles in Life Sciences
Chronic Stress Elevates Telomerase Activity In Rats, Annaliese K. Beery, Jue Lin, Joshua S. Biddle, Darlene D. Francis, Elizabeth H. Blackburn, Elissa S. Epel
Chronic Stress Elevates Telomerase Activity In Rats, Annaliese K. Beery, Jue Lin, Joshua S. Biddle, Darlene D. Francis, Elizabeth H. Blackburn, Elissa S. Epel
Neuroscience: Faculty Publications
The enzyme telomerase lengthens telomeres—protective structures containing repetitive DNA sequences at chromosome ends. Telomere shortening is associated with diseases of ageing in mammals. Chronic stress has been related to shorter immune-cell telomeres, but telomerase activity under stress may be low, permitting telomere loss, or high, partially attenuating it. We developed an experimental model to examine the impacts of extended unpredictable stress on telomerase activity in male rats. Telomerase activity was 54 per cent higher in stressed rats than in controls, and associated with stress-related physiological and behavioural outcomes. This significant increase suggests a potential mechanism for resilience to stress-related replicative …
Collaborative Online Writing Assignments To Foster Active Learning, Richard F. Olivo
Collaborative Online Writing Assignments To Foster Active Learning, Richard F. Olivo
Neuroscience: Faculty Publications
To help students master the content of a neurophysiology course, they were asked to participate in collaborative writing projects. In the first two years, students contributed to a class wiki by summarizing one lecture and editing summaries of several others. In the second two years, students worked in teams of three or four to write a series of illustrated chapters spanning the entire semester. The second assignment kept students more engaged than the wiki project, and although they found it a significant amount of work, they also believed that it helped them learn the subject matter. Working in teams, however, …
Focal Adhesion Kinase Modulates Cdc42 Activity Downstream Of Positive And Negative Axon Guidance Cues, Jonathan P. Myers, Estuardo Robles, Allison Ducharme-Smith, Timothy M. Gomez
Focal Adhesion Kinase Modulates Cdc42 Activity Downstream Of Positive And Negative Axon Guidance Cues, Jonathan P. Myers, Estuardo Robles, Allison Ducharme-Smith, Timothy M. Gomez
Neuroscience: Faculty Publications
There is biochemical, imaging and functional evidence that Rho GTPase signaling is a crucial regulator of actin-based structures such as lamellipodia and filopodia. However, although Rho GTPases are believed to serve similar functions in growth cones, the spatiotemporal dynamics of Rho GTPase signaling has not been examined in living growth cones in response to known axon guidance cues. Here we provide the first measurements of Cdc42 activity in living growth cones acutely stimulated with both growth-promoting and growthinhibiting axon-guidance cues. Interestingly, we find that both permissive and repulsive factors can work by modulating Cdc42 activity, but in opposite directions. We …
Enhancement And Suppression Of Ultradian And Circadian Rhythms Across The Female Hamster Reproductive Cycle, Brian J. Prendergast, Annaliese K. Beery, Matthew J. Paul, Irving Zucker
Enhancement And Suppression Of Ultradian And Circadian Rhythms Across The Female Hamster Reproductive Cycle, Brian J. Prendergast, Annaliese K. Beery, Matthew J. Paul, Irving Zucker
Neuroscience: Faculty Publications
The impact of ovarian hormones on hamster ultradian rhythms (URs) is unknown. We concurrently monitored URs and circadian rhythms (CRs) of home cage locomotor activity during the estrous cycle, pregnancy, and lactation of Syrian hamsters. URs with a mean period of 4–5 h were evident during the dark phase in more than 90% of females on days 1 and 2 of the estrous cycle but were significantly less prevalent on cycle days 3 and 4. The period of the UR did not vary as a function of estrous cycle stage, but at all stages, the UR period was longer in …
Age-Related Changes In The Daily Rhythm Of Photoreceptor Functioning And Circuitry In A Melatonin-Proficient Mouse Strain, Kenkichi Baba, Francesca Mazzoni, Sharon Owino, Susana Contreras-Alcantara, Enrica Strettoi, Gianluca Tosini
Age-Related Changes In The Daily Rhythm Of Photoreceptor Functioning And Circuitry In A Melatonin-Proficient Mouse Strain, Kenkichi Baba, Francesca Mazzoni, Sharon Owino, Susana Contreras-Alcantara, Enrica Strettoi, Gianluca Tosini
Neuroscience: Faculty Publications
Retinal melatonin is involved in the modulation of many important retinal functions. Our previous studies have shown that the viability of photoreceptors and ganglion cells is reduced during aging in mice that lack melatonin receptor type 1. This demonstrates that melatonin signaling is important for the survival of retinal neurons. In the present study, we investigate the effects of aging on photoreceptor physiology and retinal organization in CH3-f+/+ mice, a melatonin proficient mouse strain. Our data indicate that the amplitude of the a and b waves of the scotopic and photopic electroretinogram decreases with age. Moreover, the daily rhythm in …