Valproate prevents the induction of sensitization to methylphenidate (ritalin) in rats.
نویسندگان
چکیده
Repetitive exposure to methylphenidate (MPD) elicits sensitization to its locomotor effects. Drugs that affect the GABA system may modify adaptations to drug exposure. Therefore, we have examined the effect of sodium valproate, which enhances GABA function, on the development of sensitization to MPD using an automated, computerized animal activity monitoring system to record each rat's motor activities for 15 consecutive days. Rats were recorded before and after saline injection (Days 1-2) to provide baseline activity. Animals were then randomly assigned to the following three groups that received: (1) 2.5 mg/kg MPD (s.c.) for six consecutive days (Days 3-8), (2) a single dose of valproate (50 mg/kg; i.p.) 1 h prior to the first (Day 3) of six daily doses of MPD (2.5 mg/kg; s.c. ), or (3) five daily doses of valproate (50 mg/kg, i.p.) 1 h prior to MPD (2.5 mg/kg, s.c.) on Days 4-8. There was no drug treatment during the next 5 days (Days 9-13). All rats were then re-challenged with MPD (2.5 mg/kg, s.c.) on Day 14. Group 2 rats were also re-challenged with 50 mg/kg valproate followed by 2.5 mg/kg MPD 1 h later on Day 15. Administration of MPD alone produced a sensitized response. Multiple valproate injections prevented the induction of MPD-elicited sensitization in all four motor indices, while a single valproate injection prevented the induction of MPD-elicited sensitization in two of four motor indices studied. In conclusion, a single injection 50 mg/kg valproate given prior to any MPD treatment partially blocked the induction of MPD sensitization while repeated injections of valproate co-administered with MPD treatment completely prevented this effect.
منابع مشابه
P-32: Histological Study of Cauda Epididymis in Adult Rats Treated with Methylphenidate
Background: Methylphenidate commonly known as Ritalin is one of the most common medications. The administration of Ritalin leads to increase of the activity of central nervous system. Because of this property, Ritalin may be used for maintaining alertness and improving of attention which may lead to increase of the risk of substance abuse in some cases. There is a little data about the effects ...
متن کاملP-32: Histomorphological Study of Testicular Seminiferous Tubules Following Time Dependent Administration of Methylphenidate in Adult Rats
Background: Methylphenidate (MPH), Ritalin, is one of the most common medications. The administration of Ritalin leads to increase of the activity of central nervous system. Ritalin may be used for maintaining alertness and improving of attention which may lead to increase of the risk of substance abuse in some cases. There is a little data about the effects of long term treatment with Methylph...
متن کاملPrefrontal cortex glutamate afferents are essential for acute and chronic effects of Ritalin
Background Progressive augmentation of behavioral response following repeated psychostimulant administrations is known as behavioral sensitization, and is an experimental indicator of a drug’s liability for abuse (Robinson and Berridge, 1993; Dafny and Yang, 2006). It is known that Ritalin or methylphenidate (MPD), a drug used to treat Attention-Deficit Hyperactivity Disorder (ADHD), induces se...
متن کاملBehavioral sensitization and cross-sensitization between methylphenidate amphetamine, and 3,4-methylenedioxymethamphetamine (MDMA) in female SD rats.
The psychostimulants amphetamine and methylphenidate (MPD/Ritalin) are the drugs most often used to treat attention deficit hyperactivity disorder (ADHD). In addition, students of all ages take these drugs to improve academic performance but also abuse them for pleasurable enhancement. In addition, other psychostimulants such as 3,4-methylenedioxymethamphetamine (MDMA/ecstasy) are used/abused f...
متن کاملThe Synergistic Effects of Methylphenidate on the Behavioral Effects of Nicotine
The Synergistic Effects of Methylphenidate on the Behavioral Effects of Nicotine by Kristen K. Leedy One of the most common childhood disorders, attention-deficit hyperactivity disorder (ADHD) places individuals at a higher risk for nicotine (NIC) dependence. Approximately 37.2% of individuals with ADHD currently smoke compared to the 18.3% of individuals with no record of mental illness. Methy...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Brain research
دوره 887 2 شماره
صفحات -
تاریخ انتشار 2000