Dopamine transporter knockout (DAT KO) mice display elevated extracellular dopamine amounts in brain locations that are the striatum as well as the nucleus accumbens, however, not the prefrontal cortex. obstructed by mecamylamine, the 7 nACh receptor antagonist methyllycaconitine or Method100635, as the 42 nACh receptor antagonist dihydro–erythroidinehydrobromide (DHE) created only a nonsignificant development toward attenuation Tariquidar of nicotine results. Finally, we noticed that administration from the 5-HT1A receptor agonist 8-OH-DPAT also ameliorated the deficit in PPI seen in DAT KO mice. This amelioration was antagonized by pretreatment with Method100635. These data support the theory that nicotine might ameliorate a number of the cognitive dysfunctions within schizophrenia within a 5-HT1A-dependent style. microdialysis (Shen et al., 2004). DAT KO mice display behavioral modifications, many associated with these adjustments in dopaminergic function, including hyperlocomotion (Sora et al., 1998; Gainetdinov et al., 1999b), cognitive deficits (Li et al., 2010; Morice et al., 2007), and impairments of prepulse inhibition (PPI) from the startle reflex (Arime et al., in press; Ralph et al., 2001; Yamashita et al., 2006). Pharmacological remedies that may ameliorate these deficits in DAT Rabbit Polyclonal to NDUFB10 KO mice consist of psychostimulants, norepinephrine transporter (NET) blockers and DA antagonists. Several lines of evidence suggest possible serotonergic influences on nicotine effects in DAT KO mice. In previous work examining the molecular basis of cocaine conditioned place preference, both DAT as well as the serotonin transporter (SERT) were found to be engaged (Hall et al., 2002; Sora et al., Tariquidar 2001). Serotonergic mechanisms have already been suggested to have locomotion-decreasing effects in DAT KO mice (Gainetdinov et al., 1999b). As the precise serotonin receptor subtypes that may underlie these differences between DAT KO and wild type (WT) mice have yet to become elucidated, treatment with 5-HT1A receptor antagonists can attenuate cocaine-induced hyperactivity in rats (Muller Tariquidar et al., 2002). This result shows that 5-HT1A systems might play a significant role in psychostimulant-mediated behavioral effects. Furthermore, post mortem brain tissue from schizophrenia patients displays increased amounts of prefrontal cortical 5-HT1A receptor binding sites (Burnet et al., 1997). Treatment with 5-HT1A receptor agonists can have beneficial effects on cognitive function in schizophrenia patients treated with atypical antipsychotic drugs (Sumiyoshi et al., 2007). However, we’ve no information regarding possible serotonergic involvement in the beneficial ramifications of nicotine or cognitive deficits in schizophrenia. We have now report ramifications of nicotine on hyperlocomotion and sensory gating deficits in DAT KO mice, aswell as study of the roles for 5-HT1A receptors Tariquidar in these procedures using 5-HT1A receptor agonists and antagonists. 2. Materials and methods 2.1. Animals DAT KO mice (Sora et al., 1998) were bred at the pet Laboratory Institute of Tohoku University Graduate School of Medicine and maintained on the mixed genetic background combining C57BL/6 and 129Sv mouse strains. Offspring from heterozygote crosses were weaned at 28 days postnatal and housed in sets of two to five (segregated by sex), within a temperature- and light-controlled colony (lights on at 0800 h, lights off at 2000 h), with water and food available = 8C12 per treatment condition per genotype). In experiments examining the result of nicotine in DAT KO mice after receptor antagonists, WT and DAT KO mice were first habituated Tariquidar for 20 min after pretreatment with 2 mg/kg of nonspecific nACh receptor antagonist mecamylamine or 1 mg/kg of specific 5-HT1A antagonist WAY100635, and injected with nicotine (1 mg/kg) or saline. Locomotor activity was assessed for 60 min post-nicotine or saline injection (= 8C12 per treatment condition per genotype). 2.3.2. Measurement of startle response and prepulse inhibition Startle chambers (SR-LAB, NORTH PARK Instruments, NORTH PARK, CA) were utilized to gauge the startle response. Each chamber contains a non-restrictive Plexiglas cylinder mounted on the frame inside.