In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Q: Context: Chronic marijuana use has been associated with impairments of learning, memory, and executive functions. Little is known, however, about the effects of marijuana use on other cognitive domains, such as decision-making, which are thought to play an important role in addiction and drug abuse.', 'The purpose of the present study was to determine if long-term heavy marijuana users employ different decision-making strategies than individuals with minimal marijuana exposure.', 'Volunteers were assigned to a cannabis (n = 10) or control group (n = 10) based upon history of prior marijuana use. Demographic and neuropsychological variables were evaluated, and a decision-making task--the gambling task (GT) was administered.', 'Although few demographic and neuropsychological differences were noted between groups, marijuana users made more decisions that led to larger immediate gains despite more costly losses than controls.\Question: Do long-term heavy marijuana users make costly decisions on a gambling task?

A: These data suggest that long-term heavy marijuana users may have specific deficits in the ability to balance rewards and punishments that may contribute to continued drug-taking behavior. It is unknown, however, whether the basis for such deficits might be attributed directly to marijuana exposure or pre-existing genetic or behavioral differences.
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Q: Context: Opioid-induced spastic paraplegia after transient spinal cord ischemia during aortic surgery has been reported. Opioids modulate neurotransmission through mu () opioid receptors (MORs) in the spinal ventral horn. However, their effects during ischemic insult are not understood.', 'The effects of the selective agonist [D-Ala(2),-N-Me-Phe(4), Gly(5)-ol]enkephalin (DAMGO) on ischemia-induced agonal currents were examined in the spinal lamina IX neurons of neonatal rats by using the whole-cell patch-clamp technique. Ischemia was simulated in vitro by oxygen/glucose deprivation.', 'DAMGO (1 M) produced outward currents in ~60% of spinal lamina IX neurons at a holding potential of -70 mV. Superfusion with ischemia-simulating medium elicited an agonal current. The latency was 457 18 s. Despite its neuromodulatory effects, DAMGO did not significantly change the latencies of the agonal currents with (440 23 s) or without (454 33 s) DAMGO-induced currents.\Question: Does the mu opioid receptor activation affect ischemia-induced agonal currents in rat spinal ventral horn?

A: Activation of MORs does not influence ongoing ischemia-induced neuronal death. Our findings indicate that MOR agonist administration should be suitable as an anesthetic during aortic surgery.
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Q: Context: Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive and easily tolerated method of altering cortical physiology. To date, numerous open and sham controlled clinical trials have explored the antidepressant potential of rTMS. In the present study, we investigated clinical trials of high-frequency rTMS (20 Hz) for treatment of refractory depression, and also examined the effect of rTMS on plasma levels of catecholamine metabolites and brain-derived neurotropic factor (BDNF).', 'Twenty-six depressed inpatients who met the DSM-IV criteria for major depressive disorder and had failed to respond to treatment with at least two antidepressant drugs given at adequate doses (above 150 mg/day in an equivalent dose of imipramine) and durations (at least 4 weeks for each drug) were enrolled in this study. Eleven were males, 15 females. The ages of the subjects ranged from 19 to 78 years old (mean +/- SD = 52.9 +/- 17.8). All patients were administered left prefrontal 20 Hz rTMS at 80 % MT (total 800 pulses a day) over ten daily sessions. The plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were analyzed by high-performance liquid chromatography. The plasma levels of BDNF were also measured with the sandwich ELISA method.', 'The mean 17-item Hamilton Rating Scale for Depression (Ham-D) score of 20.5 +/- 5.2 before rTMS was significantly decreased to 15.6 +/- 7.3 after rTMS. Nine of 26 patients (35 %) demonstrated some improvement (Ham-D > or = 25 %) by rTMS. The levels of plasma MHPG, but not those of HVA, were significantly reduced after rTMS treatment, and a negative correlation was observed between the change in plasma MHPG levels and the change in scores of agitation. In addition, the plasma levels of BDNF were significantly increased by 23 % in responders and partial responders, but not in nonresponders, after rTMS treatment, and a trend for association was found between the changes in Ham-D scores and changes in plasma BDNF levels in all patients after rTMS treatment.\Question: Does high-frequency repetitive transcranial magnetic stimulation improve refractory depression by influencing catecholamine and brain-derived neurotrophic factors?

A:
These results suggest that rTMS treatment brings about some improvement in refractory depression, especially for symptoms such as agitation, by influencing MHPG and BDNF, which is in accordance with previous reports showing that BDNF was increased by various antidepressants treatments.
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