"Signal to Noise" Ratio of a Novel Object Increased By Ritalin: A Study with Two Rat Strains

Document Type


Publication Date

Summer 2012


My research was designed to investigate the effects of Ritalin (methylphenidate) administration on the novelty-seeking behavior of two rat strains, the Occidental high saccharin-preferring (HiS) and low saccharin-preferring (LoS) rats. These two rat lines were bred along differing preferences for the taste of saccharin diluted in water, and a variety of other traits have come along with this divergence, including reactivity (LoS > HiS), hedonic behavior (HiS > LoS), and tendency to self-administer drugs (HiS > LoS).

Novelty-seeking involves the investigation, by a rat, of a new or unknown object in the center of a familiar space. Rats prefer to avoid “open” spaces, but novel objects tend to bring them away from walls mmore often.

Administration of Ritalin may be increasing the salience (“noticeability”) of the object, which could tie into the drug’s clinical use. By examining the reactions of the different strains, we may be able to gather information valuable for assessing Ritalin’s efficacy with various human phenotypes, who also show differing behavioral characteristics along taste preferences. This work could thus be of value to both the clinical field and to future investigators engaged in their own research.

The drug appears to be having a large impact on the rats’ behavior, increasing time spent in the central zone by quite a bit. This effect appears to be more apparent in the HiS rats; non-drug HiS spent less time in the center than did control LoS, but methylphenidate HiS actually spent more time in the center.

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Creative Commons Attribution-Noncommercial-Share Alike 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.


Dale Chapman




Howard Hughes Medical Institute Undergraduate Science Education Grant

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