LE3 .A278 2011

2011

Hillier, Kirk

Acadia University

Bachelor of Science

Honours

Biology

Biology

Octopamine (OA), a biogenic amine, is known to modulate many physiological processes in invertebrates. One such effect of OA is an increase in cardiac output. Previous studies have also shown that OA assists in learning and memory in Heliothine moths. Epinastine (EPI) is a compound which acts as an OA antagonist. The purpose of this study is to investigate the effect of EPI on learning and memory, as well as the effects of OA and EPI on heart rate. To study the former, the proboscis extension reflex (PER), based on the Pavlovian conditioning model, was used. PER is the extension of the proboscis as a reflex to feed, elicited by sucrose stimulation applied to the antennae. Specimens of Heliothis virescens were injected with saline (control) or EPI and conditioned to extend their proboscis during the presentation of an odour. In the second experiment, the effect of OA and EPI on heart rate was examined in Helicoverpa zea. Moths were dissected to expose the heart, which was bathed in saline (control), OA, and finally EPI in four consecutive trials. Following exposure, the beats per minute of the heart were counted. In the PER experiment, a slight increase in PER response during recall was seen in moths that were treated with EPI, compared to control moths. These data suggest that EPI could be hindering initial learning, and is metabolized before the 45 minute recall begins, as no hindrance is seen at recall trials. In the heart rate experiments, a gradual decrease in heart rate was seen over the time period of the experiment. In both trials, heart rate decreased following OA and EPI administration. Addition of OA or EPI, therefore, has little to no effect on the moth heart rate. Continued study of the OA/EPI effect on memory and heart rate has the potential to provide useful insights into stress in general.

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https://scholar.acadiau.ca/islandora/object/theses:838