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Interactions between hippocampal and cerebellar theta oscillations during cerebellar theta-contingent trace eyeblink conditioning acquisition and extinction in the rabbit.

Hoffmann, Loren C
http://rave.ohiolink.edu/etdc/view?acc_num=miami1397834474

Abstract Details

2014, Doctor of Philosophy, Miami University, Psychology.
The cerebellum is required for all forms of eyeblink classical conditioning (EBCC). The hippocampus also becomes essential as the time constraints of cerebellar plasticity are exceeded, such as in the case of trace EBCC. Despite reports of modulations of learning related unit activity between these two areas during acquisition, no direct connections between dorsal hippocampus and cerebellum exist and the relationship between the cerebellum and hippocampus during this task remains a major unanswered question for neurobiological theories of EBCC. Previous research from our lab has used a brain-computer interface (BCI) to control naturally-occurring extremes of hippocampal theta state between groups during training trials and has demonstrated that hippocampal theta-contingent trial presentation of trace EBCC corresponds to enhanced learning rate and a concomitant synchronization of hippocampus and cerebellar regions (Hoffmann & Berry, 2009). In light of these findings, questions on the nature of cerebellar theta and the degree of independence of theta oscillations in these two structures have surfaced. Using the well-articulated model of mammalian associative learning, trace EBCC, two experiments are presented that address the impact of synchronized versus desynchronized hippocampal-cerebellar oscillations during different phases of the learning process. Experiment I compares theta-based coordination of hippocampus and cerebellum during cerebellar theta-contingent and hippocampal theta-contingent trace EBCC. Cerebellar non-theta is accompanied by significantly larger learning deficits late in training while hippocampal triggering effects are strongest during early learning. The location and timing of theta as well as hippocampo-cerebellar synchrony in LFPs supports an early role for hippocampus and a later role for cerebellar theta in coordinating the distributed system. Experiment II assesses the relationship of cerebellar theta to extinction of trace EBCC. Pretrial cerebellar theta delays extinction, especially for animals in which theta-state remained constant from acquisition through extinction. Averaged intertrial LFP data do not as closely correspond to the observed behavioral effects as was presented for the LFP-behavior relationship during acquisition. Together, the data provide important new insights into the behavioral impact of cerebellar theta as well as the nature of the underlying hippocampal cerebellar theta synchronization and its cognitive benefits.
Stephen Berry, Ph.D. (Advisor)
Jennifer Quinn, Ph.D. (Committee Member)
Dragana Ivkovic-Claflin, Ph.D. (Committee Member)
Barbara Oswald, Ph.D. (Committee Member)
Kathleen Killian, Ph.D. (Committee Member)
122 p.
Neurobiology; Neurosciences
Oscillations, theta, cerebellum, hippocampus, eyeblink, classical conditioning, acquisition, extinction, brain-computer interface, cognitive enhancement

Recommended Citations

Citations

  • Hoffmann, L. C. (2014). Interactions between hippocampal and cerebellar theta oscillations during cerebellar theta-contingent trace eyeblink conditioning acquisition and extinction in the rabbit. [Doctoral dissertation, Miami University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=miami1397834474

    APA Style (7th edition)

  • Hoffmann, Loren. Interactions between hippocampal and cerebellar theta oscillations during cerebellar theta-contingent trace eyeblink conditioning acquisition and extinction in the rabbit. . 2014. Miami University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=miami1397834474.

    MLA Style (8th edition)

  • Hoffmann, Loren. "Interactions between hippocampal and cerebellar theta oscillations during cerebellar theta-contingent trace eyeblink conditioning acquisition and extinction in the rabbit. ." Doctoral dissertation, Miami University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1397834474

    Chicago Manual of Style (17th edition)

miami1397834474
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This open access ETD is published by Miami University and OhioLINK.