Huie, John Russell (2008-05). The role of BDNF in spinal learning. Master's Thesis. Thesis uri icon

abstract

  • Previous 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.
  • Previous 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.

publication date

  • May 2008