%0 Journal Article
%T Differential Effect of the Dopamine Agonist ( )-7-Hydroxy-2-(N,N-di-n-propylamino) Tetralin (7-OH-DPAT) on Motor Activity between Adult Wistar and Sprague-Dawley Rats after a Neonatal Ventral Hippocampus Lesion
%A Sonia Guzm¨¢n-Vel¨¢zquez
%A Linda Garc¨¦s-Ram¨ªrez
%A Gonzalo Flores
%A Fidel De La Cruz
%A Sergio R. Zamudio
%J International Journal of Medicinal Chemistry
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/648960
%X The neonatal ventral hippocampal lesion (nVHL) has been widely used as an animal model for schizophrenia. Rats with an nVHL show several delayed behavioral alterations that mimic some symptoms of schizophrenia. Sprague-Dawley (SD) rats with an nVHL have a decrease in D3 receptors in limbic areas, but the expression of D3 receptors in Wistar (W) rats with an nVHL is unknown. The 7-Hydroxy-2-(N,N-di-n-propylamino) tetralin (7-OH-DPAT) has been reported as a D3-preferring agonist. Thus, we investigated the effect of ( )-7-OH-DPAT (0.25£¿mg/kg) on the motor activity in male adult W and SD rats after an nVHL. The 7-OH-DPAT caused a decrease in locomotion of W rats with an nVHL, but it did not change the locomotion of SD rats with this lesion. Our results suggest that the differential effect of 7-OH-DPAT between W and SD rats with an nVHL could be caused by a different expression of the D3 receptors. These results may have implications for modeling interactions of genetic and environmental factors involved in schizophrenia. 1. Introduction Dopamine (DA) receptors are classified into two broad families, namely, the D1-like (D1 and D5) and D2-like (D2, D3, and D4) receptors [1]. The D3 receptor was first cloned and characterized by Sokoloff et al. in 1990 [2]. It is negatively coupled to adenylate cyclase. In rats, the D3 receptor is mostly distributed in projection areas of the mesocorticolimbic dopaminergic system, for example, the nucleus accumbens, olfactory tubercle, islands of Calleja, and prefrontal cortex [3¨C6]. Although the role of the D3 receptor in the brain function has not been completely established, it has been related to behavioral aspects such as locomotion, emotion, and cognition [6¨C11]. The D3 receptor has also been implicated in disorders, such as schizophrenia and drug abuse, because its pharmacology and pattern of location in the brain is consistent with defective neural circuits seen in such disorders [12, 13]. For example, postmortem studies suggest a D3 receptor dysfunctionality in some cortical regions of brains obtained from schizophrenic patients [14, 15]. The locomotor responses to novelty and psychostimulants seem to be regulated by D3 receptors [6, 10, 16, 17]. 7-Hydroxy-2-(N,N-di-n-propylamino) tetralin (7-OH-DPAT) has been described as a D3-preferring agonist [4, 18]. In rats, administration of low doses of 7-OH-DPAT decreases locomotion, with such reduction in locomotion attributed to a D3 autoreceptor stimulation [7], but some findings suggest that the inhibitory action of the D3 receptors on locomotion can also occur via
%U http://www.hindawi.com/journals/ijmc/2011/648960/