Date of Completion
Honors College Thesis
Honors College, College of Arts and Science Honors
cerebellum, secretin, learning, memory
Eyeblink conditioning (EBC) is an important procedure used to understand the neuronal plasticity that occurs with learning and memory. Delay EBC requires a brainstem-cerebellar circuit while the role of the cerebellum in trace EBC is not as well understood because it requires a more complex neural circuitry involving regions of the medial prefrontal cortex and hippocampus. Secretin is a neuropeptide that is found in high concentrations within the cerebellum. Previous work has shown that blocking secretin’s effects in the cerebellum with intra-cerebellar infusion of relatively large volume of a secretin receptor antagonist impairs delay EBC (Fuchs et al. 2014). Here we study the effect that intra-cerebellar infusion of 0.5 μL secretin receptor antagonist (5-27 secretin) or vehicle prior to training sessions 1 and 2 has on delay and trace EBC in rats. A 600-ms tone CS was used for the delay EBC paradigm and a 300-ms tone CS followed by a 300-ms trace interval was used for the trace EBC paradigm. For delay EBC, the delay vehicle and antagonist groups displayed similar acquisition of conditioned responses (CRs). There was a trend for the trace antagonist group to underperform compared to the trace vehicle group though not quite at a significant level. One explanation for why the results for the delay EBC do not support previous work is that slow learning occurred in the delay vehicle group that may have prevented the effects of secretin receptor antagonist from reaching significance. The trend for the trace antagonist group to display decreased acquisition of CRs suggests that the cerebellum does play an important role in trace EBC. However, in order to better understand the neural circuitry involved in trace EBC, future work should analyze the role that cerebellar secretin itself has on trace EBC.
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Kather, Josefina M., "Effects of a Secretin Receptor Antagonist on Cerebellar Learning" (2016). UVM Honors College Senior Theses. 222.