Perinatal undernutrition facilitates morphine sensitization and cross-sensitization to cocaine in adult rats: A behavioural and neurochemical study.

VELAZQUEZ E.E.; VALDOMERO A.; ORSINGHER O.A.; CUADRA G.R.

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2010 vol. 165 p. 475 - 475

p style="TEXT-ALIGN: justify; MARGIN: 0cm 0cm 0pt; mso-layout-grid-align: none" class="MsoNormal">The development of sensitization to the locomotor effects of morphine and cross-sensitization between morphine and cocaine were evaluated in adult rats submitted to a protein malnutrition schedule from the 14th day of gestation up to 30 days of age (D-rats), and compared with wellnourished animals (C-rats). Dose-response curves to morphine-induced locomotor activity (5, 7.5, 10 or 15 mg/kg, i.p., every other day for 5 days) revealed a shift to the left in D-rats compared to C-rats. This implies that D-rats showed behavioural sensitization to the lower dose of morphine used (5 mg/kg), which was ineffective in C-rats. Furthermore, when a cocaine challenge (10 mg/kg, i.p) was given 48 h after the last morphine administration, only D-rats exhibited cross-sensitization in morphine-pretreated