Repeated exposure of adolescent rats to oral methylphenidate does not induce behavioral sensitization or cross-sensitization to nicotine

Author(s)

Justo, C. C. ^[1] ; Carneiro-de-Oliveira, P. E. ^{[1, 2]} ; DeLucia, R. ^[3] ; Aizenstein, M. L. ^[3] ; Planeta, C. S. ^{[1, 2]}

Affiliation

^[1] UNESP, Farmacol Lab, Fac Ciencias Farmaceut, BR-14801902 Araraquara, SP - Brazil

^[2] Univ Fed Sao Carlos, Programa Posgrad Ciencias Fisiol, BR-13560 Sao Carlos, SP - Brazil

^[3] Univ Sao Paulo, Inst Ciencias Biomed, Lab Psicofarmacol, BR-05508 Sao Paulo - Brazil

• Document type: Journal article
• Source: Brazilian Journal of Medical and Biological Research; v. 43, n. 7, p. 651-656, JUL 2010.
• Web of Science Citations: 6

Abstract

Several lines of evidence indicate that the use of stimulant drugs, including methylphenidate (MPD), increases tobacco smoking. This has raised concerns that MPD use during adolescence could facilitate nicotine abuse. Preclinical studies have shown that repeated treatment with an addictive drug produces sensitization to that drug and usually cross-sensitization to other drugs. Behavioral sensitization has been implicated in the development of drug addiction. We examined whether repeated oral MPD administration during adolescence could induce behavioral sensitization to MPD and long-lasting cross-sensitization to nicotine. Adolescent male Wistar rats were treated orally with 10 mg/kg MPD or saline (SAL) from postnatal day (PND) 27 to 33. To evaluate behavioral sensitization to MPD in adolescent rats (PND 39), the SAL pretreated group was subdivided into two groups that received intragastric SAL (1.0 mL/kg) or MPD (10 mg/kg); MPD pretreated rats received MPD (10 mg/kg). Cross-sensitization was evaluated on PND 39 or PND 70 (adulthood). To this end, SAL-and MPD-pretreated groups received subcutaneous injections of SAL (1.0 mL/kg) or nicotine (0.4 mg/kg). All groups had 8 animals. Immediately after injections, locomotor activity was determined. The locomotor response to MPD challenge of MPD-pretreated rats was not significantly different from that of the SAL-pretreated group. Moreover, the locomotor response of MPD-pretreated rats to nicotine challenge was not significantly different from that of the SAL-pretreated group. This lack of sensitization and cross-sensitization suggests that MPD treatment during adolescence does not induce short-or long-term neuroadaptation in rats that could increase sensitivity to MPD or nicotine. (AU)

• FAPESP's process: 05/02356-0 - Methylphenidate and nicotine-induced cross-sensitization in adolescent and adult rats
• Grantee: Camila Do Couto Justo
• Support Opportunities: Scholarships in Brazil - Scientific Initiation