, 2009). For instance, pre-administration of an organotellurane avoided the establishment of the statusepilepticus in rats ( Persike et al., 2008). Besides, tellurides are promising antitumoral drugs and their chemoprotective effects can be related to their cytotoxic properties and to their ability

high throughput screening to inhibit important enzymes necessary for the tumor growth ( Engman et al., 2000 and Cunha et al., 2005). Additionally, Ávila et al. (2010) demonstrated the neuroprotective activity of a vinylic telluride compound against Mn-induced neurotoxicity. Organotellurium compounds have been also reported as antioxidants in several models of oxidative stress (Briviba et al., 1998 and Jacob et al., 2000), VE-822 chemical structure especially in brain (Ávila et al., 2008). Recently, our research group showed the antioxidant effect of telluroacetylenes on rat brain homogenate in vitro ( Souza et al., 2009). Moreover, 2-phenyletinil-butyltellurium (PEBT) ( Fig. 1), a telluroacetylene compound, protected against oxidative damage caused by sodium nitroprusside in mouse brain, suggesting an antioxidant effect in vivo of this compound ( Souza et al., 2009). Glutamate has a pivotal role in neuroplasticity, learning and memory processes (Flood et al., 1990, Izquierdo and Medina, 1997, Castellano et al., 2001 and Whitlock et al., 2006). The central nervous system strictly regulates the fine balance between glutamate

release and uptake. When glutamate is released in the synaptic cleft, it is uptaked by specific high affinity Na+-dependent amino acid transporters, which are mainly present in glial cells, and metabolized by the glutamine pathway, transported as glutamine to the neurons and Dipeptidyl peptidase stored as glutamate now in the vesicles of pre-synaptic neuron to be released again (Fykse and Fonnum, 1996, Danbolt, 2001 and Sheldon and Robinson, 2007). In that way, facilitated glutamate transmission leads to consequent increase in learning

(Lhullier et al., 2004 and Mameli et al., 2005). In view of the pharmacological properties of organotellurium compounds, the present study evaluated the effect of PEBT on the three stages of memory, acquisition, consolidation and retrieval, employing the step-down inhibitory avoidance task in mice. Moreover, the involvement of glutamate uptake and release in the improvement of memory caused by PEBT were investigated. PEBT was prepared according to the literature method (Comasseto et al., 1996). Analysis of the 1HNMR and 13CNMR spectra showed that PEBT synthesized exhibited analytical and spectroscopic data in full agreement with its assigned structure. PEBT was diluted in canola oil. l-[3H]glutamate (specific activity 30 Ci/mmol) was purchased from Amersham International, UK. All other chemicals were obtained of the analytical grade and from standard commercial suppliers. The experiments were conducted using male adult Swiss mice (25–35 g) from our own breeding colony.