scholarly journals Behavioural and Neurochemical Consequences of MDMA Self-Administration in Rats

2021 ◽  
Author(s):  
◽  
Jennifer Do
Keyword(s):  
Clinical Investigation ◽  
Brain Regions ◽  
High Dose ◽  
The Novel ◽  
Novelty Seeking ◽  
Self Administration ◽  
Lower Lip ◽  
Tissue Levels ◽  
Impaired Attention ◽  
The Right

<p>Rationale: Over the past few decades, MDMA has been shown to produce persistent detrimental effects. Animal models have been developed to investigate the effects of self-administered drugs on brain and behaviour, but only a limited number of studies have investigated effects of MDMA. Objectives: The present thesis sought to determine the effects of MDMA self-administration on working memory and tissue levels of 5HT in rats. The role of the 5HT₁ₐ autoreceptor in MDMA-produced deficits in tissue levels of 5HT was also evaluated using neurochemical and behavioural assays. Methods: Rats self-administered a total of 165mg/kg MDMA, and were then tested in the Novel Object Recognition (NOR) task 1 week or 9 weeks following the last session of MDMA self-administration. Tissue levels of 5HT were measured in separate groups of rats, following self-administration of a total dose of 165mg/kg or 315mg/kg. 8-OH-DPAT-induced lower lip retraction (LLR) was measured in rats 2 weeks following either self-administered (315mg/kg) or experimenter-administered (40mg/kg) MDMA. In subsequent studies, chronic 8-OH-DPAT (daily injections over 7 days; 1.0mg/kg/day), chronic trazodone (continuous infusion over 14 days via osmotic minipump; 10mg/kg/day) and tryptophan loading (oral administration over 7 days; 125mg/day via gavaging needle) were administered after MDMA treatment (either self-administered; 315mg/kg or experimenter-administered; 40mg/kg) and tissue levels of 5HT were measured. Results: Self-administered MDMA produced deficits in NOR that recovered 10 weeks following self-administration. There was a small decrease in tissue levels of 5HT at both 2 weeks and 10 weeks following the low dose of self-administered MDMA. Two weeks following the high dose, tissue levels of 5HT were decreased by about 30% in all brain regions examined, and there was recovery 10 weeks following exposure. 8-OH-DPAT-induced LLR was unchanged in MDMA-treated rats. Furthermore, none of the treatments restored tissue levels of 5HT following MDMA exposure, even though the treatment (chronic 8-OH-DPAT) shifted the basal 8-OH-DPAT-induced LLR curve to the right, suggesting autoreceptor desensitisation. Conclusions: Self-administered MDMA produced deficits in NOR, which may reflect impaired attention, encoding, novelty seeking or other cognitive processes. Dose- and time-dependent deficits in tissue levels of 5HT were modest compared to those produced by experimenter-administered MDMA. Therefore, MDMA self-administration may be important for pre-clinical investigation of long-term consequences of MDMA. The findings are not consistent with the idea that the 5HT₁ₐ autoreceptor became supersensitive as a result of MDMA exposure, and it is therefore not a viable pharmacological target for restoring tissue levels of 5HT.</p>

scholarly journals Behavioural and Neurochemical Consequences of MDMA Self-Administration in Rats

2021 ◽  
Author(s):  
◽  
Jennifer Do
Keyword(s):  
Clinical Investigation ◽  
Brain Regions ◽  
High Dose ◽  
The Novel ◽  
Novelty Seeking ◽  
Self Administration ◽  
Lower Lip ◽  
Tissue Levels ◽  
Impaired Attention ◽  
The Right

<p>Rationale: Over the past few decades, MDMA has been shown to produce persistent detrimental effects. Animal models have been developed to investigate the effects of self-administered drugs on brain and behaviour, but only a limited number of studies have investigated effects of MDMA. Objectives: The present thesis sought to determine the effects of MDMA self-administration on working memory and tissue levels of 5HT in rats. The role of the 5HT₁ₐ autoreceptor in MDMA-produced deficits in tissue levels of 5HT was also evaluated using neurochemical and behavioural assays. Methods: Rats self-administered a total of 165mg/kg MDMA, and were then tested in the Novel Object Recognition (NOR) task 1 week or 9 weeks following the last session of MDMA self-administration. Tissue levels of 5HT were measured in separate groups of rats, following self-administration of a total dose of 165mg/kg or 315mg/kg. 8-OH-DPAT-induced lower lip retraction (LLR) was measured in rats 2 weeks following either self-administered (315mg/kg) or experimenter-administered (40mg/kg) MDMA. In subsequent studies, chronic 8-OH-DPAT (daily injections over 7 days; 1.0mg/kg/day), chronic trazodone (continuous infusion over 14 days via osmotic minipump; 10mg/kg/day) and tryptophan loading (oral administration over 7 days; 125mg/day via gavaging needle) were administered after MDMA treatment (either self-administered; 315mg/kg or experimenter-administered; 40mg/kg) and tissue levels of 5HT were measured. Results: Self-administered MDMA produced deficits in NOR that recovered 10 weeks following self-administration. There was a small decrease in tissue levels of 5HT at both 2 weeks and 10 weeks following the low dose of self-administered MDMA. Two weeks following the high dose, tissue levels of 5HT were decreased by about 30% in all brain regions examined, and there was recovery 10 weeks following exposure. 8-OH-DPAT-induced LLR was unchanged in MDMA-treated rats. Furthermore, none of the treatments restored tissue levels of 5HT following MDMA exposure, even though the treatment (chronic 8-OH-DPAT) shifted the basal 8-OH-DPAT-induced LLR curve to the right, suggesting autoreceptor desensitisation. Conclusions: Self-administered MDMA produced deficits in NOR, which may reflect impaired attention, encoding, novelty seeking or other cognitive processes. Dose- and time-dependent deficits in tissue levels of 5HT were modest compared to those produced by experimenter-administered MDMA. Therefore, MDMA self-administration may be important for pre-clinical investigation of long-term consequences of MDMA. The findings are not consistent with the idea that the 5HT₁ₐ autoreceptor became supersensitive as a result of MDMA exposure, and it is therefore not a viable pharmacological target for restoring tissue levels of 5HT.</p>

Eosinophilic vasculitis: an inhabitual and resistant manifestation of a vasculitis

VASA ◽  
2010 ◽  
Vol 39 (4) ◽  
pp. 344-348 ◽  
Author(s):  
Jandus ◽  
Bianda ◽  
Alerci ◽  
Gallino ◽  
Marone
Keyword(s):  
Skin Biopsy ◽  
Intravenous Iron ◽  
Small Vessel Vasculitis ◽  
High Dose ◽  
Raynaud Phenomenon ◽  
The Third ◽  
Left Elbow ◽  
Right Hand ◽  
The Right ◽  
Trunk Skin

A 55-year-old woman was referred because of diffuse pruritic erythematous lesions and an ischemic process of the third finger of her right hand. She was known to have anaemia secondary to hypermenorrhea. She presented six months before admission with a cutaneous infiltration on the left cubital cavity after a paravenous leakage of intravenous iron substitution. She then reported a progressive pruritic erythematous swelling of her left arm and lower extremities and trunk. Skin biopsy of a lesion on the right leg revealed a fibrillar, small-vessel vasculitis containing many eosinophils.Two months later she reported Raynaud symptoms in both hands, with a persistent violaceous coloration of the skin and cold sensation of her third digit of the right hand. A round 1.5 cm well-delimited swelling on the medial site of the left elbow was noted. The third digit of her right hand was cold and of violet colour. Eosinophilia (19 % of total leucocytes) was present. Doppler-duplex arterial examination of the upper extremities showed an occlusion of the cubital artery down to the palmar arcade on the right arm. Selective angiography of the right subclavian and brachial arteries showed diffuse alteration of the blood flow in the cubital artery and hand, with fine collateral circulation in the carpal region. Neither secondary causes of hypereosinophilia nor a myeloproliferative process was found. Considering the skin biopsy results and having excluded other causes of eosinophilia, we assumed the diagnosis of an eosinophilic vasculitis. Treatment with tacrolimus and high dose steroids was started, the latter tapered within 12 months and then stopped, but a dramatic flare-up of the vasculitis with Raynaud phenomenon occurred. A new immunosupressive approach with steroids and methotrexate was then introduced. This case of aggressive eosinophilic vasculitis is difficult to classify into the usual forms of vasculitis and constitutes a therapeutic challenge given the resistance to current immunosuppressive regimens.

Analytical Study of Violence Theme in Victoria Schwab’s This Savage Song

2019 ◽  
Keyword(s):  
Analytical Study ◽  
Research Paper ◽  
The Novel ◽  
Vicious Cycle ◽  
Aggressive Approach ◽  
Research Article ◽  
The People ◽  
The Social ◽  
Different Dimensions ◽  
The Right

This research article focuses on the theme of violence and its representation by the characters of the novel “This Savage Song” by Victoria Schwab. How violence is transmitted through genes to next generations and to what extent socio- psycho factors are involved in it, has also been discussed. Similarly, in what manner violent events and deeds by the parents affect the psychology of children and how it inculcates aggressive behaviour in their minds has been studied. What role is played by the parents in grooming the personality of children and ultimately their decisions to choose the right or wrong way has been argued. In the light of the theory of Judith Harris, this research paper highlights all the phenomena involved: How the social hierarchy controls the behaviour. In addition, the aggressive approach of the people in their lives has been analyzed in the light of the study of second theorist Thomas W Blume. As the novel is a unique representation of supernatural characters, the monsters, which are the products of some cruel deeds, this research paper brings out different dimensions of human sufferings with respect to these supernatural beings. Moreover, the researcher also discusses that, in what manner the curse of violence creates an inevitable vicious cycle of cruel monsters that makes the life of the characters turbulent and miserable.

The Right to Dream: Gender, Modernity, and the Problem of Class in Kate O'Brien's Bourgeois Bildungsromane

2019 ◽  
Vol 49 (2) ◽  
pp. 276-289
Author(s):  
Naoise Murphy
Keyword(s):  
Middle Class ◽  
Identity Formation ◽  
Coming Of Age ◽  
Female Identity ◽  
Gender And Sexuality ◽  
The Novel ◽  
Class Status ◽  
The Right ◽  
Aristocratic Culture ◽  
Modern Form

Feminist critics have celebrated Kate O'Brien's pioneering approach to gender and sexuality, yet there has been little exploration of her innovations of the coming-of-age narrative. Creating a modern Irish reworking of the Bildungsroman, O'Brien's heroines represent an idealized model of female identity-formation which stands in sharp contrast to the nationalist state's vision of Irish womanhood. Using Franco Moretti's theory of the Bildungsroman, a framing of the genre as a thoroughly ‘modern’ form of the novel, this article applies a critical Marxist lens to O'Brien's output. This reading brings to light the ways in which the limitations of the Bildungsroman work to constrain O'Brien's subversive politics. Their middle-class status remains an integral part of the identity of her heroines, informing the forms of liberation they seek. Fundamentally, O'Brien's idealization of aristocratic culture, elitist exceptionalism and ‘detachment of spirit’ restricts the emancipatory potential of her vision of Irish womanhood.

Homosexuality in K. Sello Duiker’s The Quiet Violence of Dreams: Demythologising the Imaginings and Universalising the Reality

Imbizo ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Adetunji Kazeem Adebiyi-Adelabu
Keyword(s):  
Coming Out ◽  
The Novel ◽  
Same Sex ◽  
Black African ◽  
Sex Preference ◽  
National Allegory ◽  
Critical Attention ◽  
Sex Orientation ◽  
The Right

Sello Duiker’s The Quiet Violence of Dreams offers an extensive treatment of homosexuality, a preoccupation which, until recently, is rare in black African fiction. On this account, as well as its depth and openness, the work has attracted some critical attention. It has been read from a masculinity perspective, as a coming-out novel, as a national allegory, as a work that challenges the notion of fixed sexuality, as a work that normalises same-sex sexuality, and so forth. Unlike these studies, this article examines the representation and disquisition around same-sex preference in the novel, with a view to demonstrating how some myths about homosexuality are exploded in the groundbreaking work, and showing that the narrative could also be apprehended as intellectual advocacy for the right to same-sex orientation.

Neural Underpinnings of Numerical and Spatial Cognition: An fMRI Meta-Analysis of Brain Regions Associated with Symbolic Number, Arithmetic, and Mental Rotation

2019 ◽  
Author(s):  
Zachary Hawes ◽  
H Moriah Sokolowski ◽  
Chuka Bosah Ononye ◽  
Daniel Ansari
Keyword(s):  
Mental Rotation ◽  
Parietal Lobe ◽  
Meta Analysis ◽  
Likelihood Estimation ◽  
Brain Regions ◽  
Angular Gyrus ◽  
Number Representation ◽  
Neural Underpinnings ◽  
The Right ◽  
Symbolic Number

Where and under what conditions do spatial and numerical skills converge and diverge in the brain? To address this question, we conducted a meta-analysis of brain regions associated with basic symbolic number processing, arithmetic, and mental rotation. We used Activation Likelihood Estimation (ALE) to construct quantitative meta-analytic maps synthesizing results from 86 neuroimaging papers (~ 30 studies/cognitive process). All three cognitive processes were found to activate bilateral parietal regions in and around the intraparietal sulcus (IPS); a finding consistent with shared processing accounts. Numerical and arithmetic processing were associated with overlap in the left angular gyrus, whereas mental rotation and arithmetic both showed activity in the middle frontal gyri. These patterns suggest regions of cortex potentially more specialized for symbolic number representation and domain-general mental manipulation, respectively. Additionally, arithmetic was associated with unique activity throughout the fronto-parietal network and mental rotation was associated with unique activity in the right superior parietal lobe. Overall, these results provide new insights into the intersection of numerical and spatial thought in the human brain.

CYBERCHONDRIA INFORMATION CLINIC: Internet's Impact on your Health (Preprint)

2019 ◽  
Author(s):  
Valentina Escotet Espinoza
Keyword(s):  
Human Life ◽  
Brain Regions ◽  
Physical Symptoms ◽  
Digital Design ◽  
Somatization Disorder ◽  
The Internet ◽  
Cultural Aspects ◽  
Starting Point ◽  
The Right ◽  
The Relationship

UNSTRUCTURED Over half of Americans report looking up health-related questions on the internet, including questions regarding their own ailments. The internet, in its vastness of information, provides a platform for patients to understand how to seek help and understand their condition. In most cases, this search for knowledge serves as a starting point to gather evidence that leads to a doctor’s appointment. However, in some cases, the person looking for information ends up tangled in an information web that perpetuates anxiety and further searches, without leading to a doctor’s appointment. The Internet can provide helpful and useful information; however, it can also be a tool for self-misdiagnosis. Said person craves the instant gratification the Internet provides when ‘googling’ – something one does not receive when having to wait for a doctor’s appointment or test results. Nevertheless, the Internet gives that instant response we demand in those moments of desperation. Cyberchondria, a term that has entered the medical lexicon in the 21st century after the advent of the internet, refers to the unfounded escalation of people’s concerns about their symptomatology based on search results and literature online. ‘Cyberchondriacs’ experience mistrust of medical experts, compulsion, reassurance seeking, and excessiveness. Their excessive online research about health can also be associated with unnecessary medical expenses, which primarily arise from anxiety, increased psychological distress, and worry. This vicious cycle of searching information and trying to explain current ailments derives into a quest for associating symptoms to diseases and further experiencing the other symptoms of said disease. This psychiatric disorder, known as somatization, was first introduced to the DSM-III in the 1980s. Somatization is a psycho-biological disorder where physical symptoms occur without any palpable organic cause. It is a disorder that has been renamed, discounted, and misdiagnosed from the beginning of the DSMs. Somatization triggers span many mental, emotional, and cultural aspects of human life. Our environment and social experiences can lay the blueprint for disorders to develop over time; an idea that is widely accepted for underlying psychiatric disorders such as depression and anxiety. The research is going in the right direction by exploring brain regions but needs to be expanded on from a sociocultural perspective. In this work, we explore the relationship between somatization disorder and the condition known as cyberchondria. First, we provide a background on each of the disorders, including their history and psychological perspective. Second, we proceed to explain the relationship between the two disorders, followed by a discussion on how this relationship has been studied in the scientific literature. Thirdly, we explain the problem that the relationship between these two disorders creates in society. Lastly, we propose a set of intervention aids and helpful resource prototypes that aim at resolving the problem. The proposed solutions ranged from a site-specific clinic teaching about cyberchondria to a digital design-coded chrome extension available to the public.

Measuring Earwax Cortisol Concentration Using a Non-Stressful Method (Preprint)

2020 ◽  
Author(s):  
Andrés Herane-Vives
Keyword(s):  
Cortisol Level ◽  
Local Stress ◽  
Extraction Methods ◽  
Cortisol Concentration ◽  
The Novel ◽  
Sampling Device ◽  
Related Factors ◽  
Novel Device ◽  
Cortisol Levels ◽  
The Right

BACKGROUND “Short-term” samples are not the most appropriate for reflecting Chronic Cortisol Concentration (CCC). Although hair is used for reflecting the systemic cortisol level over “long-term”, its use appears clinically problematic. Local stress and non-stress related factors may release a circumscribed cortisol secretion that is accumulated in hair. Non-stressful earwax extraction methods may provide a more accurate specimen to measure CCC. OBJECTIVE Correlate cortisol levels using hair, serum and earwax samples METHODS Earwax from both ears of 37 controls were extracted using a clinical procedure commonly associated with local pain. One month later, earwax from the left ear side was extracted using the same procedure, and earwax from the right ear side was comfortably extracted, using an earwax self-sampling device. Participants also provided one centimetre of hair that represented the retrospective month of cortisol output, and one serum sample that reflected the effect of systemic stressors on cortisol levels. Earwax (ECC), Hair (HCC) and Serum (SCC) Cortisol Concentration were correlated and compared. Confounders´ effect on cortisol levels were studied. RESULTS Serum showed the largest and hair the lowest cortisol concentration (p<0.01). Left-ECC was larger than Right-ECC (p=0.03). Right-ECC was the only sample unaffected by confounders (all p>0.05). Right-ECC and HCC showed the only significant association (r=0.39; p=0.03). CONCLUSIONS The self-sampling device did not represent a local stressor for the ceruminous glands. It provided the cortisol level with the least likely to be affected by confounding factors over the previous month. ECC using the novel device may constitute another accurate, but more suitable and affordable specimen for measuring CCC.

Growth of prefrontal and limbic brain regions and anxiety disorders in children born very preterm

2021 ◽  
pp. 1-12
Author(s):  
Courtney P. Gilchrist ◽  
Deanne K. Thompson ◽  
Bonnie Alexander ◽  
Claire E. Kelly ◽  
Karli Treyvaud ◽  
...  
Keyword(s):  
Anxiety Disorder ◽  
Anxiety Disorders ◽  
Orbitofrontal Cortex ◽  
Developmental Trajectories ◽  
Brain Regions ◽  
Social Risk ◽  
Intracranial Volume ◽  
Total Brain Volume ◽  
Very Preterm ◽  
The Right

Abstract Background Children born very preterm (VP) display altered growth in corticolimbic structures compared with full-term peers. Given the association between the cortiocolimbic system and anxiety, this study aimed to compare developmental trajectories of corticolimbic regions in VP children with and without anxiety diagnosis at 13 years. Methods MRI data from 124 VP children were used to calculate whole brain and corticolimbic region volumes at term-equivalent age (TEA), 7 and 13 years. The presence of an anxiety disorder was assessed at 13 years using a structured clinical interview. Results VP children who met criteria for an anxiety disorder at 13 years (n = 16) displayed altered trajectories for intracranial volume (ICV, p < 0.0001), total brain volume (TBV, p = 0.029), the right amygdala (p = 0.0009) and left hippocampus (p = 0.029) compared with VP children without anxiety (n = 108), with trends in the right hippocampus (p = 0.062) and left medial orbitofrontal cortex (p = 0.079). Altered trajectories predominantly reflected slower growth in early childhood (0–7 years) for ICV (β = −0.461, p = 0.020), TBV (β = −0.503, p = 0.021), left (β = −0.518, p = 0.020) and right hippocampi (β = −0.469, p = 0.020) and left medial orbitofrontal cortex (β = −0.761, p = 0.020) and did not persist after adjusting for TBV and social risk. Conclusions Region- and time-specific alterations in the development of the corticolimbic system in children born VP may help to explain an increase in anxiety disorders observed in this population.

The sharp bounds of the second and third Hankel determinants for the class 𝓢𝓛*

2020 ◽  
Vol 70 (4) ◽  
pp. 849-862
Author(s):  
Shagun Banga ◽  
S. Sivaprasad Kumar
Keyword(s):  
Triangle Inequality ◽  
Starlike Functions ◽  
Sharp Bound ◽  
The Novel ◽  
Sharp Bounds ◽  
Hankel Determinants ◽  
Lemniscate Of Bernoulli ◽  
Carathéodory Functions ◽  
The Right

AbstractIn this paper, we use the novel idea of incorporating the recently derived formula for the fourth coefficient of Carathéodory functions, in place of the routine triangle inequality to achieve the sharp bounds of the Hankel determinants H3(1) and H2(3) for the well known class 𝓢𝓛* of starlike functions associated with the right lemniscate of Bernoulli. Apart from that the sharp bound of the Zalcman functional: $\begin{array}{} |a_3^2-a_5| \end{array}$ for the class 𝓢𝓛* is also estimated. Further, a couple of interesting results of 𝓢𝓛* are also discussed.

Sign in / Sign up

Export Citation Format

Share Document