Journal Article 1 Flashcards
What is the overall problem being addressed by this research?
Evidence to show morphine into VTA was administered by rats but not in other regions that contained the same receptors. Is the nucleus accumbens responsible for the rewarding effects of opiates?
What is the author’s hypothesis?
Experiment 1: the rewarding effects depend on the NA
Experiment 2: verified that lesions did not disrupt the ability of rats to develop a context-specific tolerance to morphine
What was the basic method/procedure used?
Some rats were lesioned in the region of the nucleus accumbens, others were not and were given various placebo methods including anesthesia but no operation, operation but only lowering the electrodes slightly in, and another operated and electrodes were not placed within the brain. The drug morphine was used and injected as well as saline as the control to establish that morphine was in fact the reason for the conditioned place preference of the rats in the experiment. Rats were allowed to make a preference for a box, and then when confined to their non-preferred chamber they were injected with either morphine or saline and allowed to establish a new preference.
What question was it designed to answer?
Whether or not the nucleus accumbens was in fact the region entirely responsible for the rewarding effects of opiates or, in this case, morphine.
What was the independent variable?
Lesions to the NA
What were the dependent variables?
The establishment of conditioned place preference (measuring rewarding effects of morphine) or context specific tolerance (measuring tail flicks and pain tolerance)
What were the major findings of the paper?
The major findings of this paper are that the lesions of the nucleus accumbens in rats reduces opiate reward but do not alter the context-specific opiate tolerance.
Was the hypothesis supported or refuted?
Accepted
Why are the findings important?
It establishes that at least the major center for processing reward of opiates is found in the nucleus accumbens in comparison to other brain regions, and it shows that lesions within this region do not alter an animal’s ability to know where they are in space which would invalidate the assertion that the nucleus accumbens lesions fail to establish a conditioned place preference.
What are the clinical implications of this research?
Clinically, these results mean that this region of the brain is responsible for the rewarding effects that oftentimes lead to addiction, and this has greatly contributed to the opioid academic that is currently ongoing in the United States. With further understanding of the roles of the regions within the brain responsible for rewarding effects of morphine and these mechanisms, this will aid in the process of finding solutions for addiction.
