There has been quite a bit of
research involving the exact causes and effects of ethanol and alcohol on the
brain. In Dr. Roitman’s lecture, he specifically focused on the effects of
alcohol consumption on risk and reward behavior by looking at the prefrontal
cortex (PFC) and orbitofrontal cortex (OFC). The PFC is associate with higher
cognition such as working memory and executive control over things such as
goal-oriented behavior, behavioral flexibility, impulsivity, risk, patience,
and inhibitory control. It is also important to note that the PFC matures
during adolescence to dictate things such as physical development, social
development, increased myelination, pruning of excitatory synapses, and
proliferation of inhibitory circuits.
Roitman’s
lab had previously found that the level of OFC activity post either risky or
certain rewards would depend on the size, probability, and personal preference
for that reward. In the researcher’s newest study, they assigned rats one of
two conditions: alcoholic jello shots or nonalcoholic jello shots. Each rat was
given two levers to choose from: one associated with a small, but certain
payoff, and the other associated with a potentially large, but risky payoff. In
their experiment, the data demonstrated that alcohol consumption in adolescents
results in increased risky behavior in adulthood, which also were concurrent
with altered patterns of activity in the OFC. In the absence of uncertainty,
choice behavior was unaffected by adolescent intermittent ethanol (AIE)
consumption. The researchers deducted that the altered OFC neuronal population
shown in the rats that were the AIE rats could be experiencing heightened inhibitory
interneuron release. The reduced level of activity in the ethanol high rats may
be releasing inhibition on the excitatory projections from the OFC to reward
circuitry enhancing dopamine signaling. In their article, the researchers also discussed
how the differential patters of alcohol consumed by the alcohol high and low
animals is telling of neurophysiological differences, potentially originating
from adolescent development.
The neurophysiological differences were almost
exactly what researchers in New Zealand and California were studying. An
analysis was conducted that found children whose “temperament was deemed ‘undercontrolled’
at age three were more than twice as likely as well-adjusted kids to have
problems with gambling at age 21 and 32,” which is a risk-taking behavior (Time).
Researchers have yet to confirm, but have speculated, that one possibility for
these children to be at higher-risk is that there are genetic factors related
to these behaviors or that these children tend to associated with other undercontrolled
children who then manifest and increase these risky behaviors. The article then
goes on to state that:
“An
earlier analysis of the Dunedin population found that children with the most
undercontrolled behavior at ages 3 and 5 had more than three times the risk of
becoming addicted to multiple drugs as young adults, compared with those who
had exhibited the highest levels of self-control.”
Combining these
results with the results from a California study, they found that it was
actually the youths that had the best behavior as preschoolers tended to use marijuana
moderately in adolescence but had no issues controlling it. The director of the
division on addiction at Harvard Medical School explained that:
“This
means that treatment for gambling or substance problems cannot focus solely on
the addictive behavior. “Clinicians must address the full spectrum of issues
that tend to cluster with disordered gambling. It is not enough to focus
exclusively on gambling activities. Key player attributes will need attention
as well,” says Shaffer.”
These findings
once again suggest that there is a multifaceted cause and multifaceted effects
of addiction and risky behavior.
Considering the findings from both
the article by Time Magazine and Dr. Roitman’s research, the combined
implications of risk-behavior and alcohol is that there is not one true way to
pinpoint and predict this sort of behavior. There are many factors that will exponentially
increase the likelihood of this behavior such as adolescence alcohol
consumption with the OFC and PFC are still developing, childhood behavior, and
genetic factors. Future research and any attempts to help this sort of behavior
should focus on considering all of the factors and the way that they cumulate
together to affect the individual.
Works Cited
@maiasz, M. S.
(2012, April 26). Can Addictive Behaviors Be Predicted in Preschool? Retrieved
Mcmurray, M. S.,
Amodeo, L. R., & Roitman, J. D. (2015). Consequences of Adolescent
Ethanol
Consumption on Risk Preference and Orbitofrontal Cortex Encoding of Reward.
Neuropsychopharmacology, 41(5), 1366-1375. doi:10.1038/npp.2015.288
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