Summary: Young adults who drank heavily during their teenage years showed thinner cortical gray matter and modified neurotransmission.
Using MRI and TMS-EEG technology, the researchers identified lower gray matter thickness and increased N45 potential, indicative of GABA inhibitory and glutamate excitatory neurotransmitter activity.
This study highlights the long-term, deleterious effects of heavy adolescent drinking on adult brain structure and function. More research is needed to uncover the underlying mechanisms.
Key facts:
- The study showed that heavy drinking in adolescence can lead to a reduction in cortical gray matter thickness in adulthood.
- An increased N45 potential representing inhibitory activity of GABA and excitatory glutamate neurotransmitter system is observed in young adults with a history of heavy drinking.
- Areas particularly affected by heavy drinking were the frontal and parietal lobes of the brain.
source: University of Eastern Finland
During adolescence, the brain undergoes intensive development and is particularly susceptible to the harmful effects of alcohol use. According to findings from a recent follow-up study in Finland, young adults whose heavy drinking began in adolescence had lower cortical gray matter thickness and altered neurotransmission.
The findings are published in Alcohol: Clinical and Experimental Studies.
Previous research has shown that repeated binge drinking in adolescence is associated with changes in the central nervous system in adulthood, including lower gray matter volume and greater inhibitory neurotransmission.
The current study is the first to examine the relationship between gray matter thickness and neurotransmission.
The study included 26 young adults who had a history of heavy drinking, as well as 21 controls who consumed little or no alcohol. Study participants were followed for 10 years, from ages 13-18 until around age 25.
Changes in gray matter volume were measured from magnetic resonance imaging of the brain and cortical activity was measured using simultaneous transcranial magnetic stimulation and electroencephalography (TMS-EEG).
In adolescents with a history of heavy drinking, the researchers observed lower average gray matter thickness in several brain regions, as well as a larger average N45 potential, compared to adolescents who consumed little or no alcohol.
The N45 potential reflects the activity of the inhibitory GABA and excitatory glutamate neurotransmitter systems.
In the heavy drinker group, lower gray matter thickness was associated with increased N45 potential, particularly in the frontal and parietal lobes.
According to the researchers, the results show that the thinning of the cerebral cortex seen in young adults with a history of heavy drinking since adolescence is associated with altered neurotransmission, particularly in the frontal and parietal lobes. However, further research is needed to evaluate the mechanisms underlying these findings.
About this neurodevelopmental research news
Author: Major Vuore
source: University of Eastern Finland
Contact: Maj Vuorre – University of Eastern Finland
Image: Image credit: Neuroscience News
Original research: Closed access.
“Cortical thickness is inversely related to the N45 potential evoked by transcranial magnetic stimulation among young adults whose heavy drinking began in adolescence” by Virve Kekkonen et al. Clinical and experimental studies of alcoholism
Summary
Cortical thickness is inversely related to the N45 potential evoked by transcranial magnetic stimulation among young adults whose heavy drinking began in adolescence
Background
Adolescence is a particularly vulnerable stage of development in terms of the harmful effects of alcohol. Both smaller gray matter (GM) volume and greater GABAergic activity are associated with chronic alcohol consumption during adolescence. However, the relationship between these measures has not been studied.
Methods
In this exploratory study, we compared 26 young adults with a 10-year history of heavy alcohol consumption with 21 controls who consumed little or no alcohol. Simultaneous transcranial magnetic stimulation and electroencephalography were used to assess transcranial magnetic stimulation-evoked N45 potentials, reflecting the balance between GABAergic inhibition and N-methyl-D-aspartate (NMDA) receptor-mediated glutaminergic excitation in the brain. GM thickness was measured from magnetic resonance imaging and GM and N45 potentials were then correlated.
Results
Cortical thickness was significantly lower in several brain regions in the high-drinking group than the low-drinking group. N45 amplitude was significantly larger frontally in the heavy drinking group. Among the heavy drinkers, there were several statistically significant correlations between thinner GMs and larger frontal N45 amplitudes that were not detectable in the light drinkers group. The strongest correlations were found in the frontal and parietal lobes, particularly in the left superior frontal gyrus and left supramarginal gyrus, and in both hemispheres in the superior parietal lobes.
Conclusions
These findings indicate that a thinner cerebral cortex and greater inhibitory neurotransmission are associated in specific brain regions among young, long-term drinkers. Studies are needed to investigate the possible causal mechanisms underlying these effects.