Document Type


Date of Award

Summer 8-31-2005

Degree Name

Master of Science in Biomedical Engineering - (M.S.)


Biomedical Engineering

First Advisor

Stanley S. Reisman

Second Advisor

Ronald H. Rockland

Third Advisor

Saul Weiner


The present study tested the hypothesis that infusion of Prozac would serve to suppress defensive rage elicited from the medial hypothalamus of the cat. Cats are known to exhibit certain kind of behavior, known as the "defensive rage response" such as unsheathing of the claws, retraction of the ear and vocalization (hissing).

Three adult cats (2 males and 1 female) weighing (2.8 - 3.4 kg) were utilized during the experiments. Cannula-electrodes were implanted into the medial hypothalamus for elicitation of defensive rage behavior. EMG activity was recorded with a bipolar electrode attached to the masseter muscle to establish baseline before the infusion of the drug. Mean frequency values of early and late stimulation were calculated using the continuous wavelet transform.

The effects of early stimulation of the medial hypothalamus upon response latencies were compared with those of the late stimulation. The results reveal an inhibitory effect that may be related to fatigue or other inhibitory structures in the brain. The mean frequency values of the early stimulation on average were significantly higher than the mean frequency values of the late stimulation (p 0.03). While baseline (preinjection) mean values among the three subjects during early and late stimulation were highly significant (p 0.003), there were no significant differences among post-injection mean values (p >; 0.05). The findings suggest that infusion of the drug has some inhibitory influence on the masseteric EMG activity.