Biology subjects

Juraska, J. M.

Publications and source records attributed to Juraska, J. M..

3 recordsLinked to original sources

bioRxiv2023

Timing of methamphetamine exposure during adolescence differentially influences parvalbumin and perineuronal net immunoreactivity in the medial prefrontal cortex of female, but not male, rats

Adolescence involves significant reorganization within the medial prefrontal cortex (mPFC), including modifications to inhibitory neurotransmission mediated through parvalbumin (PV) interneurons and their surrounding perineuronal nets (PNNs). These developmental changes, which result in increased PV neuron activity in adulthood, may be disrupted by drug use resulting in lasting changes in mPFC function and behavior. Methamphetamine (METH), which is a readily available drug used by some adolescents, increases PV neuron activity and could influence the activity-dependent maturational process of these neurons. In the present study, we used male and female Sprague Dawley rats to test the hypothesis that METH exposure influences PV and PNN expression in a sex- and age-specific manner. Rats were injected daily with saline or 3.0 mg/kg METH from early adolescence (EA; 30-38 days old), late adolescence (LA; 40-48 days old), or young adulthood (60-68 days old). One day following exposure, effects of METH on PV cell and PNN expression were assessed using immunofluorescent labeling within the mPFC. METH exposure did not alter male PV neurons or PNNs. Females exposed in early adolescence or adulthood had more PV expressing neurons while those exposed in later adolescence had fewer, suggesting distinct windows of vulnerability to changes induced by METH exposure. In addition, females exposed to METH had more PNNs and more intense PV neuron staining, further suggesting that METH exposure in adolescence uniquely influences development of inhibitory circuits in the female mPFC. This study indicates that the timing of METH exposure, even within adolescence, influences its neural effects in females.

neuroscience↗

bioRxiv2021

Impact of pubertal onset on region-specific Esr2 expression

In female rats, pubertal onset is associated with maturation of the medial prefrontal cortex (mPFC) and mPFC-mediated behaviors. These behavioral and anatomical changes are likely due to effects of estrogen at the nuclear estrogen receptor beta (ER{beta}), which is expressed at higher levels than the estrogen receptor alpha (ER) isoform in the adult mPFC. Researchers have previously quantified ER{beta} protein and Esr2 RNA in rodents during early postnatal development and adulthood, but an adolescent-specific trajectory of this receptor in the mPFC has not been documented. Given that levels of Esr2 can fluctuate in the presence or absence of estrogens, puberty and the subsequent rise in gonadal hormones could influence ER{beta} expression in the adolescent brain. To further explore this, we used RNAscope to quantify the amount of Esr2 mRNA in pre-pubertal adolescent, recently post-pubertal adolescent, and adult female rats. We show here that Esr2 expression decreases significantly in the mPFC, striatum and motor cortex between pre-pubertal adolescence and adulthood. In the mPFC, this decrease occurs rapidly at pubertal onset, with no significant decrease in Esr2 levels between the recently post-pubertal and adult cohort. In contrast in the striatum and motor cortex, there were no significant differences in the amount of Esr2 between pre- and post-pubertal females. Insofar as the amount of Esr2 is proportional to functional ER{beta}, these results suggest ER{beta} decreases in a region-specific pattern in response to pubertal onset and highlight a role for this receptor in the maturational events that occur in the female rat mPFC at puberty.

neuroscience↗

bioRxiv2020

Influences of age and pubertal status on number of perineuronal nets in the rat medial prefrontal cortex

The prefrontal cortex (PFC) is a late developing region of the cortex, and its protracted maturation during adolescence may confer a period of plasticity. Closure of critical, or sensitive, periods in sensory cortices coincides with perineuronal net (PNN) expression, leading to enhanced inhibitory function and synaptic stabilization. PNN density is known to increase across adolescence in the male rodent medial PFC (mPFC). However, the trajectory of female PNN development has not been explored nor has the potential role of pubertal onset in PNN expression. Here, we examined rats at four time points spanning adolescent development to quantify the number of PNNs in the mPFC, as well as the total volume of the prefrontal white matter. Additionally, because puberty coincides with broad behavioral and neuroanatomical changes, we collected tissue from age-matched pre- and post- pubertal siblings within a litter. Results indicate that both males and females show an increase the total number of mPFC PNNs and in white matter under the mPFC between postnatal day (P) 30 and P60. Male puberty did not affect PNNs, while female pubertal onset led to an abrupt decrease in the total number of PNNs that persisted through mid-adolescence before increasing at P60. This decrease in female rats may indicate a difference in timing of maximal plasticity between the sexes during adolescence.

neuroscience↗