# Role of perineuronal nets in adolescent ethanol exposure in predisposing for impaired extinction recall in adulthood

> **NIH NIH F32** · MEDICAL UNIVERSITY OF SOUTH CAROLINA · 2020 · $43,035

## Abstract

PROJECT SUMMARY
The consumption of alcohol during adolescence is a significant risk factor for development of an alcohol use
disorder (AUD) as an adult. Adolescent alcohol use is thought to uniquely prime reward learning and alcohol-
cue conditioning systems. Classically conditioned cue associations can be modeled in rodents with a fear
conditioning paradigm in which a mild foot shock is paired with a tone, the conditioned cue. Extinction learning
that the tone no longer predicts a shock, is mediated by an infralimbic (IfL) cortex and basolateral amygdala
circuit. Our lab has shown that adolescent intermittent ethanol (AIE) exposure in rats slows extinction learning
and impairs extinction recall when tested in adulthood. Intriguingly, extinction learning can be enhanced by
disruption of the specialized extra cellular matrix, perineuronal nets (PNN) in the amygdala. PNNs form
preferentially around parvalbumin positive interneurons well into young adulthood in the prefrontal cortex (PFC)
including the IfL, making them vulnerable to AIE. Studies show adult repetitive drug and alcohol use increases
PNN density around parvalbumin positive interneurons. Our preliminary data suggest that AIE follows this pattern
and increases PNN density in the medial PFC. The current proposal is designed to test the hypothesis that
impairment of fear extinction learning and recall in male rats after adolescent alcohol exposure is mediated by
increases in PNN density in the IfL cortex. It is further hypothesized that females will be resistant to AIE induced
deficits in fear extinction recall, due to protection by higher circulating levels of estradiol compared to males. Aim
1 is designed to confirm preliminary results of PNN increases after AIE that persist into adulthood. Utilizing
immunohistochemical and confocal techniques these data will also examine mature sulfonation patterns of PNNs
in the PFC. These data are critical for understanding the mechanisms by which alcohol affects the developing
PFC. Aim 2 is designed to dissect alterations in parvalbumin positive interneuron activity and coordination in the
PFC that may be influenced by altered PNN configurations. Using fiber photometry will allow for the determination
of the pattern of population firing in the IfL during fear extinction learning. Furthermore, by using a wireless
multielectrode array targeting the IfL and BLA we will examine the parvalbumin interneuron coordination within
the IfL and how activity coordinates with activity in downstream amygdala. These experiments will provide novel
insight into the mechanisms by which of adolescent ethanol exposure may lead to later alcohol misuse and
inform the development of efficacious treatments.

## Key facts

- **NIH application ID:** 9847785
- **Project number:** 5F32AA027427-02
- **Recipient organization:** MEDICAL UNIVERSITY OF SOUTH CAROLINA
- **Principal Investigator:** Kristin Lee Marquardt
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $43,035
- **Award type:** 5
- **Project period:** 2019-01-01 → 2020-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9847785

## Citation

> US National Institutes of Health, RePORTER application 9847785, Role of perineuronal nets in adolescent ethanol exposure in predisposing for impaired extinction recall in adulthood (5F32AA027427-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9847785. Licensed CC0.

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