Dysregulation of brain and choroid plexus cell types in severe COVID-19.

Although SARS-CoV-2 primarily targets the respiratory system, patients with and survivors of COVID-19 can suffer neurological symptoms1-3. However, an unbiased understanding of the cellular and molecular processes that are affected in the brains of patients with COVID-19 is missing. Here we profile 65,309 single-nucleus transcriptomes from 30 frontal cortex and choroid plexus samples across 14 control individuals (including 1 patient with terminal influenza) and 8 patients with COVID-19. Although our systematic analysis yields no molecular traces of SARS-CoV-2 in the brain, we observe broad cellular perturbations indicating that barrier cells of the choroid plexus sense and relay peripheral inflammation into the brain and show that peripheral T cells infiltrate the parenchyma. We discover microglia and astrocyte subpopulations associated with COVID-19 that share features with pathological cell states that have previously been reported in human neurodegenerative disease4-6. Synaptic signalling of upper-layer excitatory neurons-which are evolutionarily expanded in humans7 and linked to cognitive function8-is preferentially affected in COVID-19. Across cell types, perturbations associated with COVID-19 overlap with those found in chronic brain disorders and reside in genetic variants associated with cognition, schizophrenia and depression. Our findings and public dataset provide a molecular framework to understand current observations of COVID-19-related neurological disease, and any such disease that may emerge at a later date.

Dehydroepiandrosterone Attenuates Cocaine-Seeking Behaviour Independently of Corticosterone Fluctuations.

The neurosteroid dehydroepiandrosterone (DHEA) is involved in the pathophysiology of several psychiatric disorders, including cocaine addiction. We have previously shown that DHEA attenuates cocaine-seeking behaviour, and also that DHEA decreases corticosterone (CORT) levels in plasma and the prefrontal cortex. Previous studies have found that rats demonstrate cocaine-seeking behaviour only when the level of CORT reaches a minimum threshold. In the present study, we investigated whether the attenuating effect of DHEA on cocaine seeking is a result of it reducing CORT levels rather than a result of any unique neurosteroid properties. Rats received either daily DHEA injections (2 mg/kg, i.p.) alone, daily DHEA (2 mg/kg, i.p.) with CORT infusion (to maintain stable basal levels of CORT; 15 mg/kg, s.c.) or vehicle (i.p.) as control, throughout self-administration training and extinction sessions. We found that both DHEA-treated and DHEA + CORT-treated groups showed a significantly lower number of active lever presses compared to controls throughout training and extinction sessions, as well as at cocaine-primed reinstatement. DHEA-treated rats showed lower CORT levels throughout the experimental phases compared to DHEA + CORT-treated and control rats. Additionally, we show that DHEA administered to cocaine-trained rats throughout extinction sessions, or immediately before reinstatement, attenuated cocaine seeking. These findings indicate that DHEA attenuates cocaine-seeking behaviour independently of fluctuations in CORT levels.

Monoamines, BDNF, Dehydroepiandrosterone, DHEA-Sulfate, and Childhood Depression-An Animal Model Study.

Basal levels of monoamines and DHEA in four main limbic brain regions were measured in prepubertal Wistar Kyoto (WKY) rats (a putative animal model of childhood depression). Basal levels of "Brain-Derived Neurotrophic Factor (BDNF)" were also determined in two regions in the hippocampus, compared with Wistar strain controls. In the second phase, we examined the responsiveness of prepubertal WKY rats to different types of chronic antidepressant treatments: Fluoxetine, Desipramine, and dehydroepiandrosterone sulfate (DHEAS). WKY prepubertal rats exhibited different monoamine levels in the limbic system, reduced DHEA levels in the VTA and lower levels of BDNF in the hippocampus CA3 region compared to controls. In prepubertal WKY rats, only treatment with DHEAS produced a statistically significant decrease in immobility, compared to saline-administered controls in the forced swim test. Wistar controls were not affected by any antidepressant. The results imply that DHEA(S) and BDNF may be involved in the pathophysiology and pharmacotherapy of childhood depression.

A cross-fostering study in a genetic animal model of depression: maternal behavior and depression-like symptoms.

Connections between maternal behavior and childhood depression were examined by using a "genetic animal model"; Flinder Sensitive Line--(FSL) rats, and cross-fostering the offspring with the control strain, Sprague Dawley (SD) rats. The control procedure was "in-fostering", where the foster dam and her pups were from the same strain. Contribution of pups' characteristics/genotype to maternal behavior was examined. After weaning, we measured male offspring's body weight, immobility in the swim test, and basal corticosterone (CORT) and adrenocorticotropin (ACTH) levels at the prepubertal age of 35 days. While maternal behavior (of "depressive-like" dams and their controls) was not altered significantly by the pups' strain, the adoption procedure per se appeared to have more adverse effects on "depressive-like" symptoms of the SD prepubertal rats than on the FSL pups. Nevertheless, the combination between abnormal maternal behavior and genetic predisposition affected the hormonal stress responses of the offspring in a more severe manner than genetic predisposition or abnormal maternal behavior per se.

DHEAS repeated treatment improves cognitive and behavioral deficits after mild traumatic brain injury.

Mild traumatic brain injury (mTBI) is characterized by diffused symptoms, which when combined are called "post-concussion syndrome". Dehydroepiandrosterone sulfate (DHEAS) is a neuroactive neurosteroid. Previously, we have reported that closed head mTBI causes long lasting cognitive deficits and depressive-like behavior. In the present study we describe the effects of DHEAS on the behavior of mice that suffered closed head mTBI. Following the induction of mTBI, mice were treated once a week with DHEAS (s.c. 20 mg/kg) and their performance in the passive avoidance test and the forced swimming test (FST) were evaluated 7, 30, 60 and 90 days post-injury. The most important interactions were between injury and injection (passive avoidance; p<0.001 and FST; p=0.001), meaning that DHEAS has beneficial effects only when given to injured animals. Our results demonstrate that the long-term cognitive and behavioral effects induced by mTBI may be improved by a repeated weekly treatment with DHEAS.

Dehydroepiandrosterone and monoamines in the limbic system of a genetic animal model of childhood depression.

Monoamines and dehydroepiandrosterone (DHEA) levels were measured in a genetic animal model for childhood depression in four subcortical structures: nucleus accumbens (Nac), ventral tegmental area (VTA), amygdala and hypothalamus. The "depressive-like" strain was the Flinders Sensitive Line (FSL), compared to their controls, Sprague-Dawley (SD) rats. Prepubertal FSL rats showed abnormal levels of only a few monoamines and their metabolites in these brain regions. This is in contrast to former studies, in which adult FSL rats exhibited significantly higher levels of all the monoamines and their metabolites measured. These different abnormal monoamine patterns between the "depressed" prepubertal rats and their adults, may help to explain why depressed children and adolescents fail to respond to antidepressant treatment as well as adults do. On the other hand, FSL prepubertal rats exhibited the same pattern of abnormal DHEA basal levels as was found in adults in previous experiments. The results from the current study may imply that treatment with DHEA could be a promising novel therapeutic option for depressed children and adolescents that fail to respond to common (monoaminergic) antidepressant treatments.

Dehydroepiandrosterone in the nucleus accumbens is associated with early onset of depressive-behavior: a study in an animal model of childhood depression.

Although the monoamine theory of depression is well studied, regarding childhood depression it is poorly supported. Antidepressant treatments affecting the monoaminergic system fail to ameliorate childhood depression in the same manner that they affect adult depression. The present study used the Flinders sensitive line (FSL) rat, a well-investigated genetic animal model of depression and Sprague-Dawley (SD) rats as controls. We co-measured monoamines and dehydroepiandrosterone (DHEA) levels in the nucleus accumbens on postnatal day 1, in prepubertal rats (35 days), and adult rats (4 months) in order to examine developmental characteristics in the monoamine systems. The results suggest that there are different ontogenetic patterns of monoaminergic activity in FSL and SD rats. While monoamine levels were different only in adulthood, FSL rats exhibited lower DHEA levels already in prepubertal childhood. These differences may be relevant to the poor response to antidepressant drugs observed in depressed children and suggest DHEA as a new marker for childhood depression.

Aggressive behavior and HPA axis hormones after social isolation in adult rats of two different genetic animal models for depression.

In the current study we explored behavioral and endocrinological effects of exposure to social isolation during adulthood in two different genetic animal models of depression, the Flinders Sensitive Line (FSL), and their controls, Sprague-Dawley (SD) rats and the Wistar-Kyoto (WKY) strain and their controls, Wistar rats. Behavioral patterns of the different strains in coping with an intruder were studied in the "aggression" or resident-intruder test. We also measured basal plasma levels of the hypothalamic-pituitary-adrenal (HPA) axis hormones corticosterone and ACTH and their levels after chronic stress (isolation). Significant alterations in the levels of HPA hormones after social isolation were noted in the "depressed-like" strains. There were no significant behavioral differences between FSL and SD rats in the "aggression" test. In contrast, WKY rats exhibited less frequent aggressive-like and social behavior compared to Wistar controls. The results suggest that the FSL and WKY strains, both genetic animal models of depression, exhibit separate patterns of HPA axis modulation and aggressive-like behavior after social isolation. These different patterns may reflect two different types of depression. An "avoidant" or socially inhibited type of depressive-like behavior is seen most clearly in the WKY strain.

Stress hormones and emotion-regulation in two genetic animal models of depression.

Children of depressed parents often exhibit emotion-regulation deficits, characterized by either excessive withdrawal or approach strategies toward the mother. The current study examined behavioral and physiological emotion-regulation in preweanling pups (postnatal day 17-19) belonging to two different genetic animal models of depression, Wistar-Kyoto (WKY) and Flinders Sensitive-Line (FSL) rats. The study also examined the effects of stress on the two animal models, hypothesizing an interactive effect of hereditary vulnerability and exposure to stress. Chronic-stress was simulated by providing limited bedding to the dam and litter for a week, in the early postnatal period. Acute-stress was generated by exposure to an adult male rat, an ethologically valid stressor. Emotion-regulation of the pups was examined using a Y-maze preference test and radioimmunoassay of Hypothalamic-Pituitary-Adrenal (HPA) axis hormones (corticosterone & adreno-corticotropin/ACTH). WKY and FSL pups exhibited reduced approach-behavior toward the dam, an emotion-regulation profile reminiscent of avoidant attachment evident in many children of depressed parents. In contrast, the two animal models did not show similar HPA axis activity. FSL pups exhibited markedly lower ACTH levels compared to controls, while WKY pups did not differ from controls. With regard to the stress manipulations, the limited-bedding condition had no effect, while the acute-stressor induced overall effects on all groups, with more pronounced reactivity evident in the WKY and FSL pups. Taken together, the experiments indicate a similar behavioral profile of the two strains at the preweanling period, while suggesting HPA dysfunction in only one of the strains.

Circulatory neurosteroid levels in underweight female adolescent anorexia nervosa inpatients and following weight restoration.

Nineteen female adolescent inpatients diagnosed with anorexia nervosa, restricting type (AN-R) and 16 non-eating disordered (ED) controls were assessed for plasma dehydroepiandrosterone (DHEA), dehydroepiandrosterone-sulphate (DHEA-S), and cortisol levels, and for eating-related and non-eating-related psychopathology. AN-R patients were assessed at admission, 1 month and 4 months following hospitalization. The non-ED controls were assessed once. No baseline between-group differences were found in plasma cortisol, DHEA, and DHEA-S levels, whereas the patient group had a significantly lower Cortisol/DHEA-S ratio and elevated scores on most psychopathological parameters. A significant increase was found in the body mass index of the AN-R patients at 4 months post-hospitalization, accompanied by a decrease in plasma cortisol levels and a trend towards decreased Cortisol/DHEA and Cortisol/DHEA-S ratios, whereas no change occurred in psychopathology. The difference in Cortisol/DHEA-S ratio between AN-R patients and non-ED controls, and the different patterns of change in cortisol vs. DHEA(-S) levels following weight restoration, may in part account for the feeding difficulties in AN, particularly during refeeding.

Analysis of neurosteroid levels in attention deficit hyperactivity disorder.

Neurosteroids are important neuroactive substrates with demonstrated involvement in several neurophysiological and disease processes. Attention deficit hyperactivity disorder (ADHD) has been associated with dysregulation of the catecholaminergic and serotonergic systems, however its relationship to irregularities or changes in neurosteroid levels remains unknown. We examined the relationship between blood levels of dehydroepiandrosterone (DHEA), its principal precursor pregnenolone and its principal metabolite dehydroepiandrosterone sulphate (DHEAS) in 29 young male subjects aged 7-15 years with DSM-IV criteria of ADHD. Subjects were evaluated by a specially designed scale, following which patients were divided into two groups according to severity of symptomatology. Results indicated significant inverse correlations between clinical symptomatology and levels of DHEA and pregnenolone in the total group. These inverse correlations were particularly evident in the less severe group of subjects. Levels of DHEA and DHEAS were inversely correlated with the hyperactivity subscale. Furthermore, using median blood levels as a cut-off indicator, higher blood levels of DHEA and DHEAS were associated with fewer ADHD symptoms, in particular hyperactivity symptomatology. Our findings suggest a possible protective effect of various neurosteroids on the expression of ADHD symptomatology.

Effect of dehydroepiandrosterone and its sulfate metabolite on neuronal cell viability in culture.

BACKGROUND: The neurosteroids dehydroepiandrosterone (DHEA) and its sulfated metabolite (DHEAS) have been reported to possess neuroprotective as well as anti-tumoral activity in vitro and in vivo. OBJECTIVES: To compare the effect of the two neurohormones on cell viability in primary whole-brain fetal mouse culture and isolated neuronal culture, as well as in a human neuroblastoma cell line (SK-N-SH). METHODS: Cell viability and cell proliferation were determined with the neutral red and 3H-thymidine uptake methods. Apoptosis in propidium iodide-stained neuroblastoma cells was determined using flow cytometry. RESULTS: DHEA (1 nM-10 microM) decreased the viability of selected primary neuronal cells (33-95% after 24 and 72 hours) but not of whole-brain cultured cells (neuron + glia). DHEAS did not significantly modify cell viability in either primary culture. In a human neuroblastoma cell line, DHEA (1 nM-1 microM) decreased 3H-thymidine uptake (30-60%) and cell viability (23-52%) after 24 hours. DHEAS did not significantly modify, or only slightly stimulated, cell viability and uptake of 3H-thymidine (132% of controls). The combination of DHEA and DHEAS neutralized the toxic effect of DHEA in both primary neuronal culture and neuroblastoma cell line. Flow cytometric analysis of DNA fragmentation in neuroblastoma cells treated with 100 nM DHEA/DHEAS for 24 hours showed an increase in apoptotic events (31.9% and 26.3%, respectively, vs. control 2.54%). CONCLUSIONS: Our results do not confirm a neuroprotective role for DHEA and suggest that DHEA and DHEAS have a differential role; DHEA possesses a neurotoxic (expressed only in isolated neurons) and anti-proliferative effect; DHEAS demonstrates only a slight neuroprotective effect.

Insulin, insulin-like growth factors-I and -II and insulin-like growth factor binding protein-3 in newborn serum: association with normal fetal head growth and head circumference.

The insulin-like growth factors (IGF) and their binding proteins (IGFBP) have been implicated in the regulation of fetal weight and length. The aim of our study was to determine the relationship between head circumference at birth and serum levels of IGF-I, IGF-II, IGFBP-3 and insulin in full-term appropriate-for-gestational age (AGA) infants. Serum samples were obtained from 77 singleton full-term neonates, 69 AGA and 8 small-for-gestational age (SGA). The AGA infants were divided into three groups by head circumference: Group 1: < or = 3rd percentile; Group 2: at 50th percentile; Group 3: > or = 97th percentile. Serum levels of IGF-I, IGF-II, IGFBP-3 and insulin were determined with commercial kits and immunometric methods. There were no statistically significant differences in mean serum levels of IGF-I, IGF-II and IGFBP-3 between the groups. A significantly higher mean serum insulin level was noted in the AGA infants with a head circumference > or = 97th percentile compared to those with a head circumference < or = 3rd percentile (4.6 +/- 0.3 vs 3.3 +/- 0.6 microU/ml; p = 0.04), and in AGA infants with a head circumference above the 50th percentile compared to those with a head circumference below the 50th percentile (4.4 +/- 0.4 vs 3.3 +/- 0.3 microU/ml; p = 0.01). AGA infants with a head circumference above or below the 50th percentile did not differ statistically in their mean IGF-II and IGFBP-3 serum level, while IGF-I differed statistically between the groups (18 +/- 2.7 vs 11.6 +/- 1.6 ng/ml, respectively; p = 0.045). Using univariate analysis, head circumference correlated positively with insulin (r = 0.29; p = 0.016) and with IGF-I (r = 0.26; p = 0.03). A stepwise multivariate linear regression analysis, however, did show statistically significant correlation of head circumference with birth weight (f = 36; p = 0.0001), and only marginally with birth length (f = 4.7; p = 0.06) and insulin (f = 3.4; p = 0.07). No correlations were found between head circumference and IGF-I, IGF-II or IGFBP-3. These data suggest that apart from genetic and nutritional factors, insulin may play a role in promoting intrauterine head growth, as reflected by head circumference at birth.

Basal plasma dehydroepiandrosterone sulfate level: a possible predictor for response to electroconvulsive therapy in depressed psychotic inpatients.

BACKGROUND: Dehydroepiandrosterone (DHEA) and its sulfate derivative DHEAS are neuroactive steroids. In the brain, they interact with gamma-aminobutyric acid (GABA(A)) receptors, which are involved in the regulation of anxiety and mood. The relevance of circulatory neurosteroids to psychiatric disorders and biological treatment is unknown. METHODS: Basal plasma levels of cortisol, DHEA, and DHEAS and the DHEAS-DHEA ratio were determined in 17 psychiatric inpatients before and after six electroconvulsive (ECT) therapy sessions, and all changes were statistically analyzed. For baseline values, 25 healthy individuals served as control subjects. Severity of depression and psychosis in the patients was measured with the Hamilton Depression Rating Scale (HDRS) and the Brief Psychiatric Rating Scale, respectively. RESULTS: Both basal and post-ECT levels of cortisol, DHEA, and DHEAS were significantly higher in the patients than in the control subjects. DHEAS levels in responding patients were higher at completion of treatment than at baseline. Patients defined as ECT nonresponders (change in HDRS < 30% from before treatments) exhibited elevated basal DHEAS levels compared with ECT responders. CONCLUSIONS: Markedly elevated basal DHEAS levels (mean + 2 SD of control value) are associated with resistance to ECT and may serve as a potential predictive marker of nonresponsiveness to ECT in depressed patients.

Elevated circulatory level of GABA(A)--antagonistic neurosteroids in patients with combat-related post-traumatic stress disorder.

BACKGROUND: Post-traumatic stress disorder (PTSD) is a multisystem neurobiological disorder with chronic alterations in various neurochemical systems. Levels of the GABA(A)--antagonistic neurosteroids plasma dehydroepiandrosterone (DHEA) and its sulphate derivate, dehydroepiandrosterone sulphate (DHEAS) may be relevant to depressive and anxiety disorders, including PTSD. METHODS: We assessed the circulatory levels of morning plasma DHEA and DHEAS in 21 male outpatients with untreated chronic combat-related PTSD (CR-PTSD), and 18 healthy control male subjects. RESULTS: Compared with the control subjects, the PTSD patients showed significantly higher plasma DHEA and DHEAS levels. CONCLUSIONS: Chronic CR-PTSD may be associated with increased circulatory level of neuroactive steroids with inhibitory activity at the GABA(A) receptors. Neurosteroid-induced decreased GABAergic tone may be relevant to the symptomatology and pathophysiology of chronic PTSD, as well as to the frequent co-morbidity of PTSD with depression and anxiety disorders.

Oxidation of polyamines in human seminal plasma: a possible role in immunological infertility.

Sixty-two specimens of seminal plasma obtained from normozoospermic, oligozoospermic, azoospermic, and immunologically infertile males were investigated. The levels of spermine, basal aldehyde, and aldehyde oxidation products were measured, as was the immunosuppressive activity of seminal plasma. No immunosuppressive activity was found in the immunologically infertile group; all other groups showed immunosuppressive activity. The immunologically infertile males showed low aldehyde oxidation products.

Evaluation of a rapid test to detect Streptococcus group A.

Rapid tests for the detection of group A beta-hemolytic streptococcus (GABHS) directly from a throat swab have become very popular. Previous studies have reported an antigen test sensitivity of 55-95% and a specificity of 88-100%. The present study evaluates the reliability of one rapid test in detecting GABHS (PathoDx). A total of 164 throat swab specimens was taken. GABHS was isolated on the culture in 37 (22.5%), and the rapid test was positive in 60 (36.6%). The sensitivity of the rapid test was 86.5% and the specificity 80%. Of the 60 positive rapid test results, 28 (47%) were false positive and the positive predicted value was 53%. We conclude that results obtained using rapid test kits should be compared to throat cultures in order to determine the reliability of such kits in specific clinical settings.

Immunosuppressive activity and polyamine levels of seminal plasma in azo-ospermic, oligospermic, and normospermic men.

Seventy specimens of human seminal plasma obtained from azo-ospermic, oligospermic, and normospermic men were tested for immunosuppressive activity on normal donor lymphocytes. Spermine and spermidine levels in acidic extracts were determined in 32 specimens of seminal plasma from the three groups. The original seminal plasma as well as the neutralized spermine extracts were examined for their effect on the functional activity of the lymphocytes. Seminal plasma obtained from the normospermic and oligospermic semen showed significant immunosuppressive activity, whereas no immunosuppressive activity was induced by seminal plasma from azo-ospermic semen. The latter finding was in accordance with the low spermine levels in azo-ospermic semen, which were about 50% of those found in normospermic and oligospermic seman. Acidic extraction of the seminal plasma of azo-ospermic origin resulted in an increase in spermine levels and also in immunosuppressive activity, demonstrating that in azo-ospermic men spermine is bound probably to a protein and is released after acidification, exerting its immunosuppressive activity only when unbound.

The influence of seminal plasma and polyaminic substances on the motility of isolated human sperm.

The purpose of the study was to examine the influence on the motility patterns of isolated human sperm of seminal plasma originating from semen of high and low motility, as well as of seminal plasma of azoospermic origin. Also assessed was the effect of incubation of sperm in the presence of solutions of the polyamines spermine, spermidine, and putrescine. The mean values of the obtained motility percentage and grade were related to the quality of sperm motility in semen and the quality of seminal plasma in that respect. The best results were obtained with specimens containing greater than or equal to 50% motile sperm and having a motility grade greater than or equal to 2. No relationship was found between the concentrations of polyamines in the seminal plasma and sperm motility of respective semen, as well as between the levels of polyamines and their effect on isolated sperm motility. It appears that the participation of polyaminic substances in the process of motility could be contributive and dependent on additional factors present in the semen.