TY - JOUR
T1 - Differential locomotor responses in male rats from three strains to acute methylphenidate
AU - Amini, Behrang
AU - Yang, Pamela B.
AU - Swann, Alan C.
AU - Dafny, Nachum
N1 - Funding Information:
Received 26 February 2004. The authors thank Mallinckrodt for their gift of methylphenidate. This study was supported in part by the Pat Rutherford Chair in Psychiatry and the National Research Service Award DA14441-01A1 (P.B.Y.). Address correspondence to Nachum Dafny, Ph.D., Health Science Center at Houston, Medical School, P.O. Box 20708, Houston, TX, USA. E-mail: Nachum.Dafny@uth.tmc.edu
PY - 2004/9
Y1 - 2004/9
N2 - Genetic variability is an important consideration in the study of the effect of drugs on humans and animals. Specifically, the effect of drugs on behavior varies from one rat strain to another. Methylphenidate (MP1)), commonly known as Ritalin, is a psychostimulant with a pharmacological profile similar to amphetamine and cocaine, and is widely used in the treatment of attention deficit/hyperactivity disorder (ADHD). The purpose of this study was to examine the acute dose-response characteristics of MPD on three different male rat strains: spontaneously hypertensive/ hyperactive rats (SHR), Wistar-Kyoto (WKY) rats, and Sprague-Dawley (SD) rats. Results showed clear differences in the pattern of behavioral response to the various MPD doses among the three rat strains. The 0.6 mg/kg MPD dose had no effect on any of the strains. At the dose of 2.5 mg/kg MPD, WKY rats reached peak locomotor activity within the initial 10 min, whereas SHR and SD rats reached peak activity in approximately 30 min. Furthermore, the effects on locomotor activity of SHR were longer in duration and higher in locomotor activity, whereas the effects on SD rats were shorter in duration and amplitude. Following the 10.0 mg/kg MPD, WKY, and SD mats reached their peak locomotor activity within 80 min post-injection, whereas SHR reached their peak locomotor activity within the initial 10 min post-injection. In addition, the SHR strain exhibited increased behavioral sensitivity to MPD as expressed by the latency, duration, and amplitude of their response. In conclusion, the dose-response experiment on the acute effects of MPD demonstrated that there are genetic differences in the responses to MPD.
AB - Genetic variability is an important consideration in the study of the effect of drugs on humans and animals. Specifically, the effect of drugs on behavior varies from one rat strain to another. Methylphenidate (MP1)), commonly known as Ritalin, is a psychostimulant with a pharmacological profile similar to amphetamine and cocaine, and is widely used in the treatment of attention deficit/hyperactivity disorder (ADHD). The purpose of this study was to examine the acute dose-response characteristics of MPD on three different male rat strains: spontaneously hypertensive/ hyperactive rats (SHR), Wistar-Kyoto (WKY) rats, and Sprague-Dawley (SD) rats. Results showed clear differences in the pattern of behavioral response to the various MPD doses among the three rat strains. The 0.6 mg/kg MPD dose had no effect on any of the strains. At the dose of 2.5 mg/kg MPD, WKY rats reached peak locomotor activity within the initial 10 min, whereas SHR and SD rats reached peak activity in approximately 30 min. Furthermore, the effects on locomotor activity of SHR were longer in duration and higher in locomotor activity, whereas the effects on SD rats were shorter in duration and amplitude. Following the 10.0 mg/kg MPD, WKY, and SD mats reached their peak locomotor activity within 80 min post-injection, whereas SHR reached their peak locomotor activity within the initial 10 min post-injection. In addition, the SHR strain exhibited increased behavioral sensitivity to MPD as expressed by the latency, duration, and amplitude of their response. In conclusion, the dose-response experiment on the acute effects of MPD demonstrated that there are genetic differences in the responses to MPD.
KW - Behavioral response
KW - Rats
KW - Ritalin
KW - SD
KW - SHR
KW - Strain differences
KW - WKY
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U2 - 10.1080/00207450490475526
DO - 10.1080/00207450490475526
M3 - Article
C2 - 15370174
AN - SCOPUS:4444319179
SN - 0020-7454
VL - 114
SP - 1063
EP - 1084
JO - International Journal of Neuroscience
JF - International Journal of Neuroscience
IS - 9
ER -