Browsing by Subject "BDNF"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Elaborative processing biases associated with vulnerability and maintenance of depression : evidence across levels of analysis(2014-08) Clasen, Peter Cunningham; Beevers, Christopher G.Major depressive disorder (MDD) will soon represent the most costly and debilitating disorder in the world. Yet, a clear model of the mechanisms underlying MDD remains elusive. This lack of clarity obscures efforts to prevent and treat MDD more effectively. This dissertation seeks to advance an integrated model of the mechanisms underlying MDD across cognitive, neural, and genetic levels of analysis. Building on the empirical foundation of cognitive theories of MDD, the dissertation includes three studies that help address questions about the cognitive mechanisms underlying depression vulnerability and maintenance. Specifically, the three studies focus on identifying 1) how elaborative processing biases, including attentional biases and rumination, give rise to specific symptoms of MDD and 2) elucidating biological mechanisms that may give rise to these biases. Together, these studies help advance an integrated model of MDD that, ultimately, may help facilitate the prevention and treatment of this costly and debilitating disorder.Item The role of BDNF in spinal learning(2009-05-15) Huie, John RussellPrevious research in our laboratory has shown that the spinal cord is capable of a simple form of instrumental learning. Spinally transected rats that receive controllable shock to an extended hindlimb exhibit a progressive increase in flexion duration that reduces net shock exposure. Subjects that receive uncontrollable shock, on the other hand, do not exhibit an increase in flexion duration, and are unable to produce this instrumental response even when they are later tested with controllable shock. This behavioral deficit can also be elicited by intermittent shock to the tail, and as little as 6 minutes of this shock is sufficient to produce a deficit that can last up to 48 hours as shown by Crown, Ferguson, Joynes, and Grau in 2002. Instrumental training has been shown to provide a number of beneficial effects. The instrumental training regimen produces a lasting effect that enables learning when subjects are later tested with a more difficult response criterion. Similarly, instrumental training can provide protection against the deleterious effects of uncontrollable shock as shown by Crown and Grau in 2001. The present study aims to determine the role of brain-derived neurotrophin factor (BDNF) in the beneficial effects of instrumental training. Experiments 1 and 2 examined the role of BDNF in the facilitory effect of instrumental training. Through the inhibition of endogenous BDNF, Experiment 1 showed that BDNF is necessary for the facilitation effect. Experiment 2 demonstrated that exogenous BDNF can produce the facilitation effect in dose-dependent fashion. Experiment 3 showed that the inhibition of BDNF attenuates the protective effect of instrumental training. Likewise, Experiment 4 showed that exogenous BDNF can substitute for instrumental training, and produce this protective effect. Experiment 5 showed that exogenous BDNF can block the development of the deficit when given immediately after uncontrollable shock. Experiment 6 showed that exogenous BDNF can block the expression of the deficit. Taken together, these experiments outline a major role for BDNF in mediating the beneficial effects of instrumental learning in the rat spinal cord.