ABSTRACT
OBJECTIVE The 5-HT2A receptor is the major target of classic hallucinogens.Both DOM(2,5-dimethoxy-4-methylamphetamine)and lisuride act at 5-HT2A receptors,and lisuride shares comparable affinity with DOM and acts as a partial agonist at 5-HT2A recep-tors.However,not like DOM,lisuride lacks hallucinogenic properties.Impulsive decision-making refers to the prefer-ence for an immediate small reinforcer(SR)over a delayed large reinforcer(LR).The current study aims to compare the effects of DOM and lisuride on impulsive decision-making and further to investigate the possible receptor mechanisms responsible for the actions of the two drugs.METHODS Impulsive decision-making was evaluated in male Sprague-Dawley rats by the percent-age of choice for the LR in delay discounting task(DDT).Delay to the LR changed in an ascending order(0,4,8,16,and 32 s)across one session.RESULTS DOM(0.3 and 0.5 mg·kg-1)increased impulsive decision-making,and the effects of DOM(0.5 mg·kg-1)was blocked by the 5-HT2A receptor antagonist ketanserin(1.0 mg·kg-1)rather than the 5-HT2C receptor antagonist SB-242084(1.0 mg·kg-1).Contrarily,lisuride(0.1,0.3 and 0.5 mg·kg-1)decreased impulsive decision-making.The effects of lisu-ride(0.3 mg·kg-1)were not antagonized by ketanserin(1.0 mg·kg-1),selective 5-HT1A antagonist WAY-100635(1.0 mg·kg-1)or selective dopamine D4 receptor antagonist L-745870(1.0 mg·kg-1),but were attenuated by the selec-tive dopamine D2/D3 receptor antagonist tiapride(40 mg·kg-1).CONCLUSION DOM and lisuride have contrasting effects on impulsive decision-making via distinct recep-tors.DOM-induced increase of impulsivity is mediated by the 5-HT2A receptor,while lisuride-induced inhibition of impulsivity is regulated by the dopamine D2/D3 receptor.
ABSTRACT
Objective To explore the intertemporal decision-making function in geriatric depressive patients and it's correlation with impulsive personality traits.Methods Forty patients with geriatric depression(GD group) and Forty demographic characteristic matched health controls (HC group) were recruited.The delay discounting task was used to measure the decision-making function,and the barratt impulsiveness scale was used to measure the impulsive traits.The delay discounting rate (k) transformed to common logarithm lgk.Results Lgk and the scores of barratt impulsiveness scale,attention impulsiveness subscale,motor impulsiveness subscale in GD group((-2.00±0.81),(42.67±8.51),(46.50± 16.84),(43.50± 10.45)) were more larger than those in HC group ((-2.31±0.51),(32.27±6.18),(34.81±8.15),(26.88±7.65),and the differences were statistically significant (t=2.060,P=0.043;t=6.252,P＜0.01;t=3.951,P＜0.01;t =8.117,P＜0.01).In addition,lgk had positive correlation with the scores of motor impulsiveness factor in GD group(r=0.408,P=0.009).Conclusion The delayed discounting ability is impaired and correlated with the motor impulsiveness in GD patients.
ABSTRACT
Objective To explore the delayed discount and personality characteristics of impulsive and premeditated male prisoners and their correlation.Methods A total of 120 male prisoners with aggressive behaviors were tested by Self-made General Situation Questionnaire,Impulsive / Premeditated Aggression Scale (IPAS),NEO Five-Factor Inventory (NEO-FFI),Delay Discount Task (DDT).The effective participants were ninety,including 51 in impulsive group and 39 in premeditated group.Analyzed the difference of delayed discount and personality characteristics between the two group.Results (1) In the delayed discount task,the delay discount rat (K) of the impulsive violence group (0.0278 ± 0.0555) was significantly higher than that of the premeditated violence group (0.0042±0.0078).The difference was statistically significant (t=3.004,P =0.004).(2) The scores of agreeableness (35.84 ± 4.08) and conscientiousness (37.04±4.83) in impulsive violence group were lower than that in premeditated violence group(38.46±5.53,42.31±5.96),and the difference was statistically significant (t=-2.587,P=0.011;t =-4.634,P＜0.01).(3) Correlation analysis showed that K value was not significantly correlated with all dimensions of the big five personality(P＞0.05).Conclusion Male impulsive prisoners have faster tendency to delay discounting compared with male premeditated prisoners.Lower agreeableness and conscientiousness are the personality characteristics of male impulsive prisoners.