In my ten-yeat experience of tenching English as major in college , I feel that students experience more difficulties in listening lessons than in other lessons. What, then, prevents students from achieving success in...In my ten-yeat experience of tenching English as major in college , I feel that students experience more difficulties in listening lessons than in other lessons. What, then, prevents students from achieving success in the listening class? I suggest that anxiety is one of the major factors, which interferes with students listening comprehension. And I would agree with writers such as Gardner and Horwitz et al. (1991)that anxiety may impede learner’s ability to perform successfully in all aspects of learning a foreign language. I feet it is particularly significant for listening.展开更多
Objective To explore the role of phosphodiesterase-2 activity in the amygdala produces anxiolytic-like effects in mice.Methods:Male ICR mice were implanted with guide cannula targeting the central nucleus of the amygd...Objective To explore the role of phosphodiesterase-2 activity in the amygdala produces anxiolytic-like effects in mice.Methods:Male ICR mice were implanted with guide cannula targeting the central nucleus of the amygdala bilaterally.Following recovery from surgery,mice were administered either Bay 60-7550 or lentiviral vector/microRNA targeted to PDE2.The effects of pharmacological inhibition were assessed 30 min post-treatment while those of PDE2 knockdown were assessed beginning one week after treatment with the lentiviral vector/microRNA.Behavioral effects were assessed in the elevated plus-maze and the tail-suspension tests;ODQ was used to assess cyclic GMP involvement.Cannula placement and viral vector localization were determined histologically via its GFP tag.Results:Administration of Bay 60-7550 into the central nucleus of the amygdala resulted in anxiolytic-and antidepressant-like effects on behavior of mice in the elevated plus-maze and tail-suspension test,respectively;these effects were blocked by pretreatment with ODQ.Viral vector/microRNA-induced knockdown of PDE2 resulted in similar effects on behavior in these tests,which also were blocked by ODQ.The treatment reduced PDE2 expression by approximately 80%.Conclusion:The present study does provide an additional line of support that reduced PDE2 activity,achieved in this case via lentiviral vector/microRNA-induced knockdown,is associated with such behavioral effects,resulting from treatment with NO donors,which also increase cyclic GMP signaling.展开更多
This brief review discusses the behavioral consequences of two pharmacologically selected lines of rats. Flinders Sensitive (FSL) and Flinders Resistant (FRL) Lines of rats were selected on the basis of differential h...This brief review discusses the behavioral consequences of two pharmacologically selected lines of rats. Flinders Sensitive (FSL) and Flinders Resistant (FRL) Lines of rats were selected on the basis of differential hypothermic and behavioral responses to the anticholinesterase, diisopropylfluorophosphate (DFP). FSL rats are more sensitive to the hypothermic effects of cholinergic, serotonergic, and dopaminergic agonists but less sensitive to the locomotor or stereotypic effects of dopamine agonists. FSL rats exhibit greater immobility in the forced swim test and reduced social interaction compared with FRL rats, but do not differ in saccharin intake, behavior in the elevated plus maze, or responses for rewarding brain self-stimulation. The exaggerated immobility and reduced social interaction are counteracted by chronic treatment with antidepressants. Because FSL rats were more sensitive to 5-HT1A receptor agonists, high (HDS) and low (LDS) 8-OH-DPATsensitive lines were selectively bred for differential hypothermic responses to the 5-HT1A receptor agonist, 8-hydroxy-2-(di-N-propylamino)tetralin (8-OH-DPAT). HDS rats were also more sensitive to the hypothermic effects of oxotremorine, a cholinergic agonist, but selection for this response did not diverge with later selection. HDS rats exhibited greater immobility in the forced swim test than LDS rats and this correlated response could be seen early in selection (generation 3). HDS rats also showed reduced social interaction compared to LDS rats, but did not differ in behavior in the elevated plus maze. These findings confirm that selection for hypothermic responses to pharmacological agents do have behavioral consequences, notably the production of depressive-like phenotypes, which can be counteracted by chronic antidepressant treatment. Because increased 5-HT1A receptor sensitivity was common to both selected lines (FSL and HDS), neurobiological processes dependent on this receptor could contribute to the abnormal behaviors that manifest in these rat lines and thus suggesting a mechanism underlying depressive behaviors in humans. However, available human data are inconsistent with this hypothesis and suggest that other mechanisms underlie these behavioral abnormalities in HDS and FSL rats. These mechanisms as well as additional behavioral testing in these rat lines will be discussed.展开更多
文摘In my ten-yeat experience of tenching English as major in college , I feel that students experience more difficulties in listening lessons than in other lessons. What, then, prevents students from achieving success in the listening class? I suggest that anxiety is one of the major factors, which interferes with students listening comprehension. And I would agree with writers such as Gardner and Horwitz et al. (1991)that anxiety may impede learner’s ability to perform successfully in all aspects of learning a foreign language. I feet it is particularly significant for listening.
文摘Objective To explore the role of phosphodiesterase-2 activity in the amygdala produces anxiolytic-like effects in mice.Methods:Male ICR mice were implanted with guide cannula targeting the central nucleus of the amygdala bilaterally.Following recovery from surgery,mice were administered either Bay 60-7550 or lentiviral vector/microRNA targeted to PDE2.The effects of pharmacological inhibition were assessed 30 min post-treatment while those of PDE2 knockdown were assessed beginning one week after treatment with the lentiviral vector/microRNA.Behavioral effects were assessed in the elevated plus-maze and the tail-suspension tests;ODQ was used to assess cyclic GMP involvement.Cannula placement and viral vector localization were determined histologically via its GFP tag.Results:Administration of Bay 60-7550 into the central nucleus of the amygdala resulted in anxiolytic-and antidepressant-like effects on behavior of mice in the elevated plus-maze and tail-suspension test,respectively;these effects were blocked by pretreatment with ODQ.Viral vector/microRNA-induced knockdown of PDE2 resulted in similar effects on behavior in these tests,which also were blocked by ODQ.The treatment reduced PDE2 expression by approximately 80%.Conclusion:The present study does provide an additional line of support that reduced PDE2 activity,achieved in this case via lentiviral vector/microRNA-induced knockdown,is associated with such behavioral effects,resulting from treatment with NO donors,which also increase cyclic GMP signaling.
文摘This brief review discusses the behavioral consequences of two pharmacologically selected lines of rats. Flinders Sensitive (FSL) and Flinders Resistant (FRL) Lines of rats were selected on the basis of differential hypothermic and behavioral responses to the anticholinesterase, diisopropylfluorophosphate (DFP). FSL rats are more sensitive to the hypothermic effects of cholinergic, serotonergic, and dopaminergic agonists but less sensitive to the locomotor or stereotypic effects of dopamine agonists. FSL rats exhibit greater immobility in the forced swim test and reduced social interaction compared with FRL rats, but do not differ in saccharin intake, behavior in the elevated plus maze, or responses for rewarding brain self-stimulation. The exaggerated immobility and reduced social interaction are counteracted by chronic treatment with antidepressants. Because FSL rats were more sensitive to 5-HT1A receptor agonists, high (HDS) and low (LDS) 8-OH-DPATsensitive lines were selectively bred for differential hypothermic responses to the 5-HT1A receptor agonist, 8-hydroxy-2-(di-N-propylamino)tetralin (8-OH-DPAT). HDS rats were also more sensitive to the hypothermic effects of oxotremorine, a cholinergic agonist, but selection for this response did not diverge with later selection. HDS rats exhibited greater immobility in the forced swim test than LDS rats and this correlated response could be seen early in selection (generation 3). HDS rats also showed reduced social interaction compared to LDS rats, but did not differ in behavior in the elevated plus maze. These findings confirm that selection for hypothermic responses to pharmacological agents do have behavioral consequences, notably the production of depressive-like phenotypes, which can be counteracted by chronic antidepressant treatment. Because increased 5-HT1A receptor sensitivity was common to both selected lines (FSL and HDS), neurobiological processes dependent on this receptor could contribute to the abnormal behaviors that manifest in these rat lines and thus suggesting a mechanism underlying depressive behaviors in humans. However, available human data are inconsistent with this hypothesis and suggest that other mechanisms underlie these behavioral abnormalities in HDS and FSL rats. These mechanisms as well as additional behavioral testing in these rat lines will be discussed.
