scholarly journals Comparison of cannabidiol to citalopram in targeting fear memory in female mice

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Zackary T. Montoya ◽  
Amy L. Uhernik ◽  
Jeffrey P. Smith
Keyword(s):  
Sexual Dimorphism ◽  
Fear Conditioning ◽  
Estrous Cycle ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Fear Memory ◽  
Memory Formation ◽  
Post Traumatic Stress ◽  
Female Mice ◽  
Memory Type ◽  
The Impact

Abstract Background Cannabidiol (CBD) and selective serotonin reuptake inhibitors (SSRIs) are currently used to treat post-traumatic stress disorder (PTSD). However, these drugs are commonly studied after dosing just prior to extinction training, and there are gaps in our understanding of how they affect fear memory formation, their comparative effects on various types of memory, and of sexual dimorphisms in effects. Also, more studies involving female subjects are needed to balance the gender-inequality in the literature. Therefore, the purpose of this study was to directly compare the effects of CBD to citalopram in affecting the formation of auditory cued, contextual, and generalized fear memory, and to evaluate how extinction of these different memories was altered by pre-acquisition treatment in female mice. We also evaluated the impact of the estrous cycle on each of these. Methods Auditory-cued trace fear conditioning was conducted shortly after dosing female C57BL/6 mice, with either CBD or citalopram (10 mg/kg each), by pairing auditory tones with mild foot shocks. Auditory-cued, contextual, and generalized fear memory was assessed by measuring freezing responses, with an automated fear conditioning system, 24 h after conditioning. Each memory type was then evaluated every 24 h, over a 4-day period in total, to create an extinction profile. Freezing outcomes were statistically compared by ANOVA with Tukey HSD post hoc analysis, N = 12 mice per experimental group. Evaluation of sexual dimorphism was by comparison to historical data from male mice. Results Auditory cue-associated fear memory was not affected with CBD or citalopram; however, contextual memory was reduced with CBD by 11%, p < 0.05, but not citalopram, and generalized fear memory was reduced with CBD and citalopram, 20% and 22%, respectively, p < 0.05. Extinction learning was enhanced with CBD and citalopram, but, there was considerable memory-type variability between drug effects, with freezing levels reduced at the end of training by 9 to 17% for CBD, and 10 to 12% with citalopram. The estrous cycle did not affect any outcomes. Conclusions Both drugs are potent modifiers of fear memory formation; however, there is considerable divergence in their targeting of different memory types which, overall, could support the use of CBD as an alternative to SSRIs for treating PTSD in females, but not males. A limitation of the study was that it compared data from experiments done at different times to evaluate sexual dimorphism. Overall, this suggests that more research is necessary to guide any therapeutic approach involving CBD.

scholarly journals Proteomic Analysis Reveals Sex-Specific Protein Degradation Targets in the Amygdala During Fear Memory Formation

2021 ◽  
Vol 14 ◽  
Author(s):  
Kayla Farrell ◽  
Madeline Musaus ◽  
Shaghayegh Navabpour ◽  
Kiley Martin ◽  
W. Keith Ray ◽  
...  
Keyword(s):  
Protein Degradation ◽  
Fear Conditioning ◽  
Degradation Process ◽  
Fear Memory ◽  
Memory Formation ◽  
Contextual Fear Conditioning ◽  
Female Rats ◽  
Protein Targets ◽  
Male And Female Rats ◽  
Ubiquitin Proteasome

Ubiquitin-proteasome mediated protein degradation has been widely implicated in fear memory formation in the amygdala. However, to date, the protein targets of the proteasome remain largely unknown, limiting our understanding of the functional significance for protein degradation in fear memory formation. Additionally, whether similar proteins are targeted by the proteasome between sexes has yet to be explored. Here, we combined a degradation-specific K48 Tandem Ubiquitin Binding Entity (TUBE) with liquid chromatography mass spectrometry (LC/MS) to identify the target substrates of the protein degradation process in the amygdala of male and female rats following contextual fear conditioning. We found that males (43) and females (77) differed in the total number of proteins that had significant changes in K48 polyubiquitin targeting in the amygdala following fear conditioning. Many of the identified proteins (106) had significantly reduced levels in the K48-purified samples 1 h after fear conditioning, suggesting active degradation of the substrate due to learning. Interestingly, only 3 proteins overlapped between sexes, suggesting that targets of the protein degradation process may be sex-specific. In females, many proteins with altered abundance in the K48-purified samples were involved in vesicle transport or are associated with microtubules. Conversely, in males, proteins involved in the cytoskeleton, ATP synthesis and cell signaling were found to have significantly altered abundance. Only 1 protein had an opposite directional change in abundance between sexes, LENG1, which was significantly enhanced in males while lower in females. This suggests a more rapid degradation of this protein in females during fear memory formation. Interestingly, GFAP, a critical component of astrocyte structure, was a target of K48 polyubiquitination in both males and females, indicating that protein degradation is likely occurring in astrocytes following fear conditioning. Western blot assays revealed reduced levels of these target substrates following fear conditioning in both sexes, confirming that the K48 polyubiquitin was targeting these proteins for degradation. Collectively, this study provides strong evidence that sex differences exist in the protein targets of the degradation process in the amygdala following fear conditioning and critical information regarding how ubiquitin-proteasome mediated protein degradation may contribute to fear memory formation in the brain.

scholarly journals Dopamine and fear memory formation in the human amygdala

2021 ◽  
Author(s):  
Andreas Frick ◽  
Johannes Björkstrand ◽  
Mark Lubberink ◽  
Allison Eriksson ◽  
Mats Fredrikson ◽  
...  
Keyword(s):  
Fear Conditioning ◽  
Dopamine Release ◽  
Conditioned Fear ◽  
Fear Memory ◽  
Memory Formation ◽  
Fear Learning ◽  
Causative Role ◽  
Endogenous Dopamine ◽  
Positron Emission ◽  
Endogenous Dopamine Release

AbstractLearning which environmental cues that predict danger is crucial for survival and accomplished through Pavlovian fear conditioning. In humans and rodents alike, fear conditioning is amygdala-dependent and rests on similar neurocircuitry. Rodent studies have implicated a causative role for dopamine in the amygdala during fear memory formation, but the role of dopamine in aversive learning in humans is unclear. Here, we show dopamine release in the amygdala and striatum during fear learning in humans. Using simultaneous positron emission tomography and functional magnetic resonance imaging, we demonstrate that the amount of dopamine release is linked to strength of conditioned fear responses and linearly coupled to learning-induced activity in the amygdala. Thus, like in rodents, formation of amygdala-dependent fear memories in humans seems to be facilitated by endogenous dopamine release, supporting an evolutionary conserved neurochemical mechanism for aversive memory formation.

scholarly journals microRNA mir-598-3p mediates susceptibility to stress-enhancement of remote fear memory

2019 ◽  
Author(s):  
Meghan E Jones ◽  
Stephanie E. Sillivan ◽  
Sarah Jamieson ◽  
Gavin Rumbaugh ◽  
Courtney A. Miller
Keyword(s):  
Basolateral Amygdala ◽  
Differential Susceptibility ◽  
Anxiolytic Effect ◽  
Bioinformatic Analysis ◽  
Fear Memory ◽  
Fear Learning ◽  
Small Rna Sequencing ◽  
Female Mice ◽  
The Impact

ABSTRACTmicroRNAs (miRNAs) have emerged as potent regulators of learning, recent memory and extinction. However, our understanding of miRNAs directly involved in regulating complex psychiatric conditions perpetuated by aberrant memory, such as in posttraumatic stress disorder (PTSD), remains limited. To begin to address the role of miRNAs in persistent memory, we performed small-RNA sequencing on basolateral amygdala (BLA) tissue to identify miRNAs altered by auditory fear conditioning (FC) one month after training. mir-598-3p, a highly conserved miRNA previously unstudied in the brain, was downregulated in the BLA. Further decreasing BLA mir-598-3p levels did not alter the expression or extinction of the remote fear memory. Given that stress is a critical component in PTSD, we next assessed the impact of stress-enhanced fear learning (SEFL) on mir-598-3p levels, finding the miRNA is elevated in the BLA of male, but not female, mice susceptible to the effects of stress in SEFL. Accordingly, intra-BLA inhibition of mir-598-3p interfered with expression and extinction of the remote fear memory in male, but not female, mice. This effect could not be attributed to an anxiolytic effect of miRNA inhibition. Finally, bioinformatic analysis following quantitative proteomics on BLA tissue collected 30 days post-SEFL training identified putative mir-598-3p targets and related pathways mediating the differential susceptibility, with evidence for regulation of the actin cytoskeleton.

Estrous cycle stage gates sex differences in prefrontal muscarinic control of fear memory formation

2019 ◽  
Vol 161 ◽  
pp. 26-36 ◽  
Author(s):  
Adam J. Kirry ◽  
Deven J. Durigan ◽  
Robert C. Twining ◽  
Marieke R. Gilmartin
Keyword(s):  
Sex Differences ◽  
Estrous Cycle ◽  
Fear Memory ◽  
Memory Formation ◽  
Estrous Cycle Stage

Cardiac contraction, calcium transients, and myofilament calcium sensitivity fluctuate with the estrous cycle in young adult female mice

2014 ◽  
Vol 306 (7) ◽  
pp. H938-H953 ◽  
Author(s):  
Jennifer K. MacDonald ◽  
W. Glen Pyle ◽  
Cristine J. Reitz ◽  
Susan E. Howlett
Keyword(s):  
Estrous Cycle ◽  
Action Potentials ◽  
Ventricular Myocytes ◽  
Fold Increase ◽  
Reproductive Hormones ◽  
Cardiac Contraction ◽  
Estrous Cycles ◽  
Female Mice ◽  
Ec Coupling ◽  
The Impact

This study established conditions to induce regular estrous cycles in female C57BL/6J mice and investigated the impact of the estrous cycle on contractions, Ca2+ transients, and underlying cardiac excitation-contraction (EC)-coupling mechanisms. Daily vaginal smears from group-housed virgin female mice were stained to distinguish estrous stage (proestrus, estrus, metestrus, diestrus). Ventricular myocytes were isolated from anesthetized mice. Contractions and Ca2+ transients were measured simultaneously (4 Hz, 37°C). Interestingly, mice did not exhibit regular cycles unless they were exposed to male pheromones in bedding added to their cages. Field-stimulated myocytes from mice in estrus had larger contractions (∼2-fold increase), larger Ca2+ transients (∼1.11-fold increase), and longer action potentials (>2-fold increase) compared with other stages. Larger contractions and Ca2+ transients were not observed in estrus myocytes voltage-clamped with shorter action potentials. Voltage-clamp experiments also demonstrated that estrous stage had no effect on Ca2+ current, EC-coupling gain, diastolic Ca2+, sarcoplasmic reticulum (SR) Ca2+ content, or fractional release. Although contractions were largest in estrus, myofilament Ca2+ sensitivity was lowest (EC50 values ∼1.15-fold higher) in conjunction with increased phosphorylation of myosin binding protein C in estrus. Contractions were enhanced in ventricular myocytes from mice in estrus because action potential prolongation increased SR Ca2+ release. These findings demonstrate that cyclical changes in reproductive hormones associated with the estrous cycle can influence myocardial electrical and contractile function and modify Ca2+ homeostasis. However, such changes are unlikely to occur in female mice housed in groups under conventional conditions, since these mice do not exhibit regular estrous cycles.

scholarly journals Kisspeptin innervation of the hypothalamic paraventricular nucleus: sexual dimorphism and effect of estrous cycle in female mice

2017 ◽  
Vol 230 (6) ◽  
pp. 775-786 ◽  
Author(s):  
Marilena Marraudino ◽  
Dèsirèe Miceli ◽  
Alice Farinetti ◽  
Giovanna Ponti ◽  
GianCarlo Panzica ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Estrous Cycle ◽  
Paraventricular Nucleus ◽  
Hypothalamic Paraventricular Nucleus ◽  
Female Mice

scholarly journals Sex-specific calibration of memory recall by glucocorticoid receptors on cortical astrocytes

2020 ◽  
Author(s):  
WW Taylor ◽  
BR Imhoff ◽  
ZS Sathi ◽  
KM Garza ◽  
BG Dias
Keyword(s):  
Fear Conditioning ◽  
Glucocorticoid Receptors ◽  
Memory Recall ◽  
Male Mice ◽  
Post Traumatic Stress ◽  
Female Mice ◽  
Cortical Astrocytes ◽  
Cell Type Specific ◽  
Post Traumatic ◽  
Female Specific

ABSTRACTDysfunctions in memory recall lead to pathological fear; a hallmark of trauma-related disorders, like Post-Traumatic Stress Disorder (PTSD). Heightened recall of an association between a cue and trauma, as well as impoverished recall that a previously trauma-related cue is no longer a threat both result in a debilitating fear toward the cue. Glucocorticoid-mediated action via the glucocorticoid receptor (GR) influences memory recall. This literature has primarily focused on GRs expressed in neurons or ignored cell-type specific contributions. To ask how GR action in non-neuronal cells influences memory recall, we combined auditory fear conditioning in mice and the knockout of GRs in astrocytes in the prefrontal cortex (PFC), a brain region implicated in memory recall. We found that GRs in astrocytes in the PFC calibrate recall in female but not male mice. Specifically, we found that knocking out GRs in astrocytes in the PFC of female mice (AstroGRKO) after fear conditioning resulted in higher recall of fear to the CS+ tone when compared to controls (AstroGRintact). While we did not find any differences in extinction of fear toward the CS+ between these groups, AstroGRKO female mice showed impaired recall of extinction training. We did not observe any significant results in male mice. These results suggest a sex-specific calibration of memory recall by GRs in astrocytes in the PFC. These data demonstrate the need to examine GR action in cortical astrocytes to elucidate the basic neurobiology underlying memory recall and potential mechanisms that underlie female-specific biases in the incidence of PTSD.

scholarly journals SUN-LB41 The Role of Androgen Receptors in Female Mouse X-Zone Loss During Aging and Pregnancy

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Emily C Frucci ◽  
Matthew J Taylor ◽  
Yewei Xing ◽  
Gary D Hammer ◽  
William E Rainey
Keyword(s):  
Sex Differences ◽  
Sexual Dimorphism ◽  
Virgin Female ◽  
Therapeutic Interventions ◽  
Minor Role ◽  
Positive Staining ◽  
Exon 2 ◽  
Female Mice ◽  
A Minor ◽  
The Impact

Abstract Introduction: Sex differences are prevalent in the risk and manifestation of numerous human diseases as well as in the response to most therapeutic interventions. While marked sexual dimorphism is observed in the development, homeostasis and most diseases of the adrenal cortex, the impact of these differences on adrenal function remains poorly understood. Sex differences include the timing of adrenal fetal zone (X-zone) regression, which occurs during male mouse puberty but only after pregnancy or advanced age in females. The mechanisms driving regression, particularly in females, are unknown. A potential regulator of adrenal sexual dimorphism and X-zone regression is androgen exposure. Through adrenocortical-specific deletion of the androgen receptor (AR), we tested the hypothesis that androgen signaling is responsible for X-zone post-pubertal regression in male mice and post-pregnancy/aging related regression in female mice. Methods: Adrenocortical-targeted Ar deletion was accomplished by crossing heterozygous aldosterone synthase-Cre mice to mice with a floxed exon 2 of Ar (ARΔAdr). Mice were sacrificed at 25 or 50 weeks of age and compared to ARf/f littermates (controls). Adrenals were processed for histology (H&E), immunofluorescence (IF) and whole adrenal mRNA RT-PCR to detect AR and X-zone specific markers Akr1c18 (20αHSD) and Pik3c2g. Results: In all mice, Ar mRNA expression was significantly decreased in ARΔAdr mice compared to control littermates. As expected, 25 week control females had higher expression of Akr1c18 (6740-fold) and Pik3c2g (198-fold) compared to 25 week control males. 25 week ARΔAdr males retained expression of Akr1c18 (20864-fold) and Pik3c2g (2802-fold) compared to controls, and also exhibited positive 20αHSD staining, confirming X-zone retention. 50 week control females exhibited histologic loss of the X-zone with negligible expression of Akr1c18 and Pik3c2g compared with 25 week control females. However, 50 week female ARΔAdr mice exhibited a histologic X-zone retention and concomitant high expression of X-zone genes (Akr1c18 67-fold, Pik3c2g 75-fold) compared to female control littermates. Furthermore, 20αHSD IF demonstrated undetectable levels in controls and positive staining in ARΔAdr, indicating that age-associated X-zone loss may be AR-mediated. Post-pregnant 25 week control mice had ~99% lower expression of both X-zone markers compared to virgin female controls. Post-pregnant ARΔAdr mice displayed higher expression of Akr1c18 (19-fold) and Pik3c2g (5-fold) compared to post-pregnant controls, though neither group had detectable 20αHSD by IF. Conclusion: Our findings indicate that AR signaling not only causes post-pubertal X-zone loss in males, but also plays a major role in the loss of the X-zone observed in aged female mice. Conversely, AR signaling may only play a minor role in X-zone regression following pregnancy.

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