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Vadnie, C. A.

Publications and source records attributed to Vadnie, C. A..

4 recordsLinked to original sources

Prenatal circadian rhythm disruption induces sex-specific substance use and mood-related phenotypes in mice

20% of Americans are at risk for environmental circadian rhythm disruptions (CRD) due to shift work, leading to substantial negative health outcomes. However, females are especially affected with greater vulnerability for substance use (SU) and adverse outcomes associated with pregnancy, including for offspring at birth and later in life. In mice, prenatal CRD (pCRD) recapitulates these risks, but it is unknown whether pCRD affects SU in mature offspring. To investigate this, C57BL/6J dams were disrupted by reversing the light/dark cycle during gestation. Following pCRD, reward- (cocaine conditioned place preference, intravenous self-administration) and mood-related behaviors (open field, elevated plus maze, light/dark box, forced swim) were measured in adult offspring. Adult female offspring of dams exposed to CRD developed an anhedonic-like phenotype with decreased food self-administration, cocaine intake and reinforcing properties of cocaine. Opposingly, pCRD male offspring showed a SU-like phenotype with increased cocaine preference, higher order food self-administration and cocaine reinforcement. Interestingly, these divergent behavioral outcomes were not specific to reward. While female pCRD mice showed increased anxiety-like behavior, pCRD males showed decreased anxiety/increased risk-taking behavior, as well as decreased immobility in the forced swim test. Rhythms in corticosterone were also sex-specifically affected by pCRD. These results suggest that pCRD may predispose individuals to distinct psychiatric disorders based on sex with mood disorders developing in females and SU disorders developing in males. By better understanding how disrupted rhythms during pregnancy affect behavior in adulthood, we can develop novel therapeutic approaches for SU and mood disorders in adults.

neuroscience↗

Comparative transcriptomic rhythms in the mouse and human prefrontal cortex

Alterations in multiple subregions of the human prefrontal cortex (PFC) have been heavily implicated in psychiatric diseases. Moreover, emerging evidence suggests that circadian rhythms in gene expression are present across the brain, including in the PFC, and that these rhythms are altered in disease. However, investigation into the potential circadian mechanisms underlying these diseases in animal models must contend with the fact that the human PFC is highly evolved and specialized relative to that of rodents. Here, we use RNA sequencing to lay the groundwork for translational studies of molecular rhythms through a sex-specific, cross species comparison of transcriptomic rhythms between the mouse medial PFC (mPFC) and two subregions of the human PFC, the anterior cingulate cortex (ACC) and the dorsolateral PFC (DLPFC). We find that while circadian rhythm signaling is conserved across species and subregions, there is a phase shift in the expression of core clock genes between the mouse mPFC and human PFC subregions that differs by sex. Furthermore, we find that the identity of rhythmic transcripts is largely unique between the mouse mPFC and human PFC subregions, with the most overlap (20%, 236 transcripts) between the mouse mPFC and the human ACC in females. Nevertheless, we find that basic biological processes are enriched for rhythmic transcripts across species, with key differences between regions and sexes. Together, this work highlights both the evolutionary conservation of transcriptomic rhythms and the advancement of the human PFC, underscoring the importance of considering cross-species differences when using animal models.

neuroscience↗

Molecular and cellular rhythms in excitatory and inhibitory neurons in the mouse prefrontal cortex

Previous studies have shown that there are rhythms in gene expression in the mouse prefrontal cortex (PFC); however, the contribution of different cell types and potential variation by sex has not yet been determined. Of particular interest are excitatory pyramidal cells and inhibitory parvalbumin (PV) interneurons, as interactions between these cell types are essential for regulating the excitation/inhibition balance and controlling many of the cognitive functions regulated by the PFC. In this study, we identify cell-type specific rhythms in the translatome of PV and pyramidal cells in the mouse PFC and assess diurnal rhythms in PV cell electrophysiological properties. We find that while core molecular clock genes are conserved and synchronized between cell types, pyramidal cells have nearly twice as many rhythmic transcripts as PV cells (35% vs. 18%). Rhythmic transcripts in pyramidal cells also show a high degree of overlap between sexes, both in terms of which transcripts are rhythmic and in the biological processes associated with them. Conversely, in PV cells, rhythmic transcripts from males and females are largely distinct. Moreover, we find sex-specific effects of phase on action potential properties in PV cells that are eliminated by environmental circadian disruption. Together, this study demonstrates that rhythms in gene expression and electrophysiological properties in the mouse PFC vary by both cell type and sex. Moreover, the biological processes associated with these rhythmic transcripts may provide insight into the unique functions of rhythms in these cells, as well as their selective vulnerabilities to circadian disruption. Significance statementThis is the first study to examine translatomic rhythms in the mouse PFC with cell-type specificity. We find that the core molecular clock cycles in phase across cell types, indicating that previously described daily oscillations in the cortical excitation/inhibition balance are not the consequence of a phase offset between PV and pyramidal cells. Nevertheless, rhythmic transcripts and their associated biological processes differ by both sex and cell type, suggesting that molecular rhythms may play a unique role in different cell types and between sexes. Therefore, our results, such as the enrichment of transcripts associated with mitochondrial function in PV cells from males, point towards possible cell and sex-specific mechanisms that could contribute to psychiatric and cognitive diseases upon rhythm disruption.

neuroscience↗

The Suprachiasmatic Nucleus Regulates Anxiety-Like Behavior in Mice

Circadian rhythms are commonly disrupted in individuals with depression and/or anxiety disorders. Animal studies indicate that circadian rhythm disruption can cause increased depressive and anxiety-like behavior, but the underlying mechanisms are unclear. Currently, there is conflicting evidence as to whether the master pacemaker in the brain, the suprachiasmatic nucleus (SCN), plays a key role in regulating psychiatric-related behavior. To investigate the role of the SCN in regulating depressive and anxiety-like behavior in mice, we directly manipulated the neural activity of the SCN using two chronic optogenetic stimulation paradigms. Repeated stimulation of the SCN late in the active phase (circadian time 21, CT21) shortened the period and dampened the amplitude of homecage activity rhythms. Repeated stimulation of the SCN at unpredictable times during the dark phase dampened, fragmented and reduced the stability of homecage activity rhythms. In both SCN optogenetic stimulation paradigms, dampened homecage activity rhythms (decreased amplitude) was associated with increased measures of anxiety-like behavior, but not in control mice. Increased fragmentation and decreased day-to-day stability of homecage activity also correlated with increased anxiety-like behavior. Unexpectedly the change in period of homecage activity rhythms was not directly associated with any psychiatric-related behavior. Furthermore, we did not observe consistent correlations between homecage activity amplitude and depressive-like behavior in stimulated mice. Taken together, these results indicate that SCN-mediated dampening of rhythms is directly correlated with increased anxiety-like, but not depressive-like behavior in mice. This work is an important step in understanding how specific SCN neural activity disruptions affect mood and anxiety-related behavior.

neuroscience↗