A systematic review of hormone treatment for children with gender dysphoria and recommendations for research.

AIM: The aim of this systematic review was to assess the effects on psychosocial and mental health, cognition, body composition, and metabolic markers of hormone treatment in children with gender dysphoria. METHODS: Systematic review essentially follows PRISMA. We searched PubMed, EMBASE and thirteen other databases until 9 November 2021 for English-language studies of hormone therapy in children with gender dysphoria. Of 9934 potential studies identified with abstracts reviewed, 195 were assessed in full text, and 24 were relevant. RESULTS: In 21 studies, adolescents were given gonadotropin-releasing hormone analogues (GnRHa) treatment. In three studies, cross-sex hormone treatment (CSHT) was given without previous GnRHa treatment. No randomised controlled trials were identified. The few longitudinal observational studies were hampered by small numbers and high attrition rates. Hence, the long-term effects of hormone therapy on psychosocial health could not be evaluated. Concerning bone health, GnRHa treatment delays bone maturation and bone mineral density gain, which, however, was found to partially recover during CSHT when studied at age 22 years. CONCLUSION: Evidence to assess the effects of hormone treatment on the above fields in children with gender dysphoria is insufficient. To improve future research, we present the GENDHOR checklist, a checklist for studies in gender dysphoria.

Posterior Orbitofrontal and Anterior Cingulate Pathways to the Amygdala Target Inhibitory and Excitatory Systems with Opposite Functions.

The bidirectional dialogue of the primate posterior orbitofrontal cortex (pOFC) with the amygdala is essential in cognitive-emotional functions. The pOFC also sends a uniquely one-way excitatory pathway to the amygdalar inhibitory intercalated masses (IM), which inhibit the medial part of the central amygdalar nucleus (CeM). Inhibition of IM has the opposite effect, allowing amygdalar activation of autonomic structures and emotional arousal. Using multiple labeling approaches to identify pathways and their postsynaptic sites in the amygdala in rhesus monkeys, we found that the anterior cingulate cortex innervated mostly the basolateral and CeM amygdalar nuclei, poised to activate CeM for autonomic arousal. By contrast, a pathway from pOFC to IM exceeded all other pathways to the amygdala by density and size and proportion of large and efficient terminals. Moreover, whereas pOFC terminals in IM innervated each of the three distinct classes of inhibitory neurons, most targeted neurons expressing dopamine- and cAMP-regulated phosphoprotein (DARPP-32+), known to be modulated by dopamine. The predominant pOFC innervation of DARPP-32+ neurons suggests activation of IM and inhibition of CeM, resulting in modulated autonomic function. By contrast, inhibition of DARPP-32 neurons in IM by high dopamine levels disinhibits CeM and triggers autonomic arousal. The findings provide a mechanism to help explain how a strong pOFC pathway, which is poised to moderate activity of CeM, through IM, can be undermined by the high level of dopamine during stress, resulting in collapse of potent inhibitory mechanisms in the amygdala and heightened autonomic drive, as seen in chronic anxiety disorders.SIGNIFICANCE STATEMENT The dialogue between prefrontal cortex and amygdala allows thoughts and emotions to influence actions. The posterior orbitofrontal cortex sends a powerful pathway that targets a special class of amygdalar intercalated mass (IM) inhibitory neurons, whose wiring may help modulate autonomic function. By contrast, the anterior cingulate cortex innervates other amygdalar parts, activating circuits to help avoid danger. Most IM neurons in primates label for the protein DARPP-32, known to be activated or inhibited based on the level of dopamine. Stress markedly increases dopamine release and inhibits IM neurons, compromises prefrontal control of the amygdala, and sets off a general alarm system as seen in affective disorders, such as chronic anxiety and post-traumatic stress disorder.

From the Golgi-Cajal mapping to the transmitter-based characterization of the neuronal networks leading to two modes of brain communication: wiring and volume transmission.

After Golgi-Cajal mapped neural circuits, the discovery and mapping of the central monoamine neurons opened up for a new understanding of interneuronal communication by indicating that another form of communication exists. For instance, it was found that dopamine may be released as a prolactin inhibitory factor from the median eminence, indicating an alternative mode of dopamine communication in the brain. Subsequently, the analysis of the locus coeruleus noradrenaline neurons demonstrated a novel type of lower brainstem neuron that monosynaptically and globally innervated the entire CNS. Furthermore, the ascending raphe serotonin neuron systems were found to globally innervate the forebrain with few synapses, and where deficits in serotonergic function appeared to play a major role in depression. We propose that serotonin reuptake inhibitors may produce antidepressant effects through increasing serotonergic neurotrophism in serotonin nerve cells and their targets by transactivation of receptor tyrosine kinases (RTK), involving direct or indirect receptor/RTK interactions. Early chemical neuroanatomical work on the monoamine neurons, involving primitive nervous systems and analysis of peptide neurons, indicated the existence of alternative modes of communication apart from synaptic transmission. In 1986, Agnati and Fuxe introduced the theory of two main types of intercellular communication in the brain: wiring and volume transmission (WT and VT). Synchronization of phasic activity in the monoamine cell clusters through electrotonic coupling and synaptic transmission (WT) enables optimal VT of monoamines in the target regions. Experimental work suggests an integration of WT and VT signals via receptor-receptor interactions, and a new theory of receptor-connexin interactions in electrical and mixed synapses is introduced. Consequently, a new model of brain function must be built, in which communication includes both WT and VT and receptor-receptor interactions in the integration of signals. This will lead to the unified execution of information handling and trophism for optimal brain function and survival.

Maintenance therapy with second generation antipsychotics for bipolar disorder - A systematic review and meta-analysis.

BACKGROUND: Second generations antipsychotics (SGA) are frequently used for maintenance treatment in bipolar disorder. We systematically reviewed the efficacy and long-term effects of treatment with SGA, regardless of treatment strategy (SGA administered either as monotherapy or as adjunctive therapy), in comparison to placebo, lithium or valproate. Primary outcomes were relapses (mood episode recurrence) and discontinuation. METHOD: Clinical studies were identified through database searching in PubMed, Embase, PsychInfo and Cochrane Library and critically appraised based on the Cochrane Handbook. Full data extraction of raw data was performed and analyzed with meta-analyses, and level of evidence graded using GRADE. Only randomized controlled studies (RCT) and observational studies were included, with a minimum follow-up of 6 months. Comparators used were restricted to placebo, lithium, valproate or other anti-epileptic drugs. RESULTS: We identified 15 RCTs on SGA in bipolar disorder with follow-up-time of 6 months up to 2 years, and one observational study reporting long-term effects of up to 4 years. A total of 6142 patients were included in the randomized trials. No long-term RCTs beyond 2 years follow-up was identified. All RCTs except for one included patients with bipolar disorder type I only. All RCTs except for two included patients pre-stabilized on the drug under investigation prior to randomization (enrichment design). For SGA as adjunctive therapy to lithium or valproate, meta-analyses showed that treatment with either aripiprazole (RR: 0.65, 95% CI 0.50-0.85), quetiapine (RR: 0.38, 95% CI 0.32-0.46) or ziprasidone (RR: 0.62, 95% CI 0.40-0.96) reduced the overall risk of relapses in patients that had responded during the stabilization phase. Adjunctive therapy with quetiapine was the only drug that reduced both manic and depressive episodes. For SGA as monotherapy, only quetiapine was shown to be better than lithium/ valproate for both manic and depressive relapses, but only for patients stabilized on quetiapine during the acute phase. As monotherapy, olanzapine, quetiapine and risperidone were shown to be superior to placebo in reducing the overall risk of relapses. LIMITATIONS: There were considerable limitations to the evidence base of maintenance treatment with SGA in bipolar disorder. Most studies used stabilized patients, i.e. enrichment design (selection bias), had considerable dropout levels (attrition bias), and variable degree of reporting bias. No long-term RCT data on efficacy is available beyond 2 years, and almost all studies are on bipolar disorder type I patients only. Despite these limitations, we elucidate quantitative findings from meta-analyses conducted on the randomized trials published on the topic.

Diagnostic accuracy of postmortem imaging vs autopsy-A systematic review.

Background Postmortem imaging has been used for more than a century as a complement to medico-legal autopsies. The technique has also emerged as a possible alternative to compensate for the continuous decline in the number of clinical autopsies. To evaluate the diagnostic accuracy of postmortem imaging for various types of findings, we performed this systematic literature review. Data sources The literature search was performed in the databases PubMed, Embase and Cochrane Library through January 7, 2015. Relevant publications were assessed for risk of bias using the QUADAS tool and were classified as low, moderate or high risk of bias according to pre-defined criteria. Autopsy and/or histopathology were used as reference standard. Findings The search generated 2600 abstracts, of which 340 were assessed as possibly relevant and read in full-text. After further evaluation 71 studies were finally included, of which 49 were assessed as having high risk of bias and 22 as moderate risk of bias. Due to considerable heterogeneity - in populations, techniques, analyses and reporting - of included studies it was impossible to combine data to get a summary estimate of the diagnostic accuracy of the various findings. Individual studies indicate, however, that imaging techniques might be useful for determining organ weights, and that the techniques seem superior to autopsy for detecting gas Conclusions and Implications In general, based on the current scientific literature, it was not possible to determine the diagnostic accuracy of postmortem imaging and its usefulness in conjunction with, or as an alternative to autopsy. To correctly determine the usefulness of postmortem imaging, future studies need improved planning, improved methodological quality and larger materials, preferentially obtained from multi-center studies.

Aromatase inhibitors alone or sequentially combined with tamoxifen in postmenopausal early breast cancer compared with tamoxifen or placebo - Meta-analyses on efficacy and adverse events based on randomized clinical trials.

Tamoxifen (TAM) and aromatase inhibitors (AI) are adjuvant therapy options for postmenopausal women with estrogen receptor positive (ER+) breast cancer. This systematic review of seven randomized controlled studies comparing TAM and AI, and one study comparing extended therapy with an AI with placebo after about 5 years of tamoxifen, aims to assess long-term clinical efficacy and adverse events. The literature review was performed according to the principles of the Cochrane Collaboration. The search included common databases up to 2013-01-14. Studies of high or moderate quality were used for grading of evidence. Revman™ software was utilized for meta-analyses of published data. Disease free survival (DFS) and overall survival (OS) were improved with AI monotherapy compared to TAM with high and moderate quality of evidence respectively. Sequenced therapy with AI → TAM (or vice versa) improved DFS compared with TAM with moderate quality of evidence, but did not improve OS (low quality of evidence). However, if only studies on sequenced AI therapy with randomization before endocrine therapy were considered, no improvement of DFS could be found. Fractures are more frequently associated with AI whereas the risk of endometrial cancer and venous thromboembolism are higher with TAM. For cardiovascular events no difference was found between AI (mono- or sequenced therapy) and TAM, whereas sequenced therapy compared with AI had lower risk of cardiovascular events (moderate level of evidence). AIs are superior to TAM as adjuvant hormonal therapy for postmenopausal ER-positive breast cancer. TAM can be considered for individual patients due to the different toxicity profile compared with AI. Cardiovascular events related to AI treatment deserve further attention.

Detection of beta-endorphin in the cerebrospinal fluid after intrastriatal microinjection into the rat brain.

We have investigated to what extent microinjected beta-endorphin could migrate from the rat brain parenchyma into the CSF compartment. Exogenous rat beta-endorphin (0.1 nmol) was microinjected into the left striatum 1 mm from the lateral ventricle in anesthetized male rats. CSF samples were collected at different time points up to 2 h post-injection from a catheter affixed to the atlanto-occipital membrane of the cisterna magna. Radioimmunoassay and mass spectrometry were performed on the CSF samples, and brain sections were immunostained for beta-endorphin and mu-opioid receptors. The beta-endorphin injected rats showed a marked increase in beta-endorphin immunoreactive (IR) material in the CSF, with a peak at 30-45 min post-injection, and this beta-endorphin-IR material existed mainly as the intact beta-endorphin peptide. The immunohistochemistry results revealed the appearance of distinct beta-endorphin-IR cell bodies in the globus pallidus and the bed nucleus of stria terminalis supracapsular part, regions distant from the injection site, at 2 h post-injection of exogenous beta-endorphin. The beta-endorphin-IR in several of the globus pallidus cell bodies colocalized with the mu-opioid receptor-IR at the cell surface. These findings show that upon delivery of synthetic beta-endorphin, there is a significant intracerebral spread of the injected peptide, reaching regions far from the site of injection via diffusion in the extracellular space and flow in the cerebrospinal fluid. This may be of relevance when interpreting studies based on intracerebral injections of peptides, and advances our knowledge regarding the migration of compounds within the brain.

Anxiolytic effects of intra-amygdaloid injection of the D1 antagonist SCH23390 in the rat.

The intercalated islands are intra-amigdaloid clusters of D1 receptor rich GABAergic neurons, which control impulse traffic between the basolateral complex and the central nucleus of the amygdala. As dopaminergic transmission within the amygdala may play a role in anxiety, the effect of the D1 antagonist SCH23390 microinjected mainly close to the rostral intercalated islands in rats was studied, using the White and Black Box test. SCH23390 reduced anxiety by an increase in the latency of the first entry into the black compartment and by an increase in the total time spent in the white compartment of the White and Black Box test, while there was no significant modification of locomotion. It is suggested that blockade of D1 receptors in the rostral intercalated islands may reduce anxiety through a reduction of GABA-mediated dishinibition of the central amygdaloid nucleus.

Linking white and grey matter in schizophrenia: oligodendrocyte and neuron pathology in the prefrontal cortex.

Neuronal circuitry relies to a large extent on the presence of functional myelin produced in the brain by oligodendrocytes. Schizophrenia has been proposed to arise partly from altered brain connectivity. Brain imaging and neuropathologic studies have revealed changes in white matter and reduction in myelin content in patients with schizophrenia. In particular, alterations in the directionality and alignment of axons have been documented in schizophrenia. Moreover, the expression levels of several myelin-related genes are decreased in postmortem brains obtained from patients with schizophrenia. These findings have led to the formulation of the oligodendrocyte/myelin dysfunction hypothesis of schizophrenia. In this review, we present a brief overview of the neuropathologic findings obtained on white matter and oligodendrocyte status observed in schizophrenia patients, and relate these changes to the processes of brain maturation and myelination. We also review recent data on oligodendrocyte/myelin genes, and present some recent mouse models of myelin deficiencies. The use of transgenic and mutant animal models offers a unique opportunity to analyze oligodendrocyte and neuronal changes that may have a clinical impact. Lastly, we present some recent morphological findings supporting possible causal involvement of white and grey matter abnormalities, in the aim of determining the morphologic characteristics of the circuits whose alteration leads to the cortical dysfunction that possibly underlies the pathogenesis of schizophrenia.

Sequence of information processing for emotions through pathways linking temporal and insular cortices with the amygdala.

The amygdala has a pivotal role in deciphering the emotional significance of sensory stimuli enabling emotional memory formation. We have previously shown that prefrontal cortices in rhesus monkeys project to the amygdala mainly from their deep layers, suggesting feedback communication. If sensory areas convey signals pertinent to the state of the environment, they should issue feedforward projections to the amygdala, arising mainly from the upper layers, consistent with the flow of information from earlier- to later-processing sensory cortices. Here we addressed this hypothesis in cases with injection of tracers in sites of the amygdala known to have robust connections with prefrontal cortices and mapped connections in insular and temporal cortices associated with sensory processing and memory. The medial temporal pole, the entorhinal and perirhinal areas, and the agranular and dysgranular insula had the densest connections with the amygdala, and the lateral temporal pole, the parahippocampal region, and the granular insula had sparser connections. Most areas projected to the amygdala predominantly from the upper layers, suggesting feedforward communication, and received reciprocal amygdalar innervation primarily in their superficial layers, suggesting feedback communication. In contrast, the entorhinal cortex issued projections to the amygdala from its deep layers, suggesting feedback communication, and received reciprocal amygdalar projections most densely in layers II-III, which project to the hippocampus. These findings may help explain how the amygdala can attach emotional value to environmental stimuli, participate in the sequence of information processing of emotions, and modulate the formation of emotional memories.

Theory relating in vitro and in vivo microdialysis with one or two probes.

In this paper, we further develop the general theory of microdialysis by extending the linear model of Bungay et al. to provide a theoretical basis for in vitro and in vivo microdialysis. Specifically, we considered the effect of active clearance processes on in vivo microdialysis, and thereby elaborated the theory of Benveniste et al. to endogenous compounds. We examined the use of steady state tissue diffusion resistance with negligible clearance processes to interpret microdialysis data. The influence of the tissue properties on the in vitro and in vivo recoveries in dual-probe microdialysis was analyzed and we simulated the effect of the operating parameters on dual probe microdialysis performance. We estimated that the minimum clearance rate constant detectable by microdialysis in a quasi-steady state is about 5.5 x 10(-5) s(-1). This minimum rate constant establishes a criterion, below which inhibition of the active clearance processes does not show detectable influences on the microdialysis extraction efficiency.

Quantitative dual-probe microdialysis: evaluation of [3H]mannitol diffusion in agar and rat striatum.

Dual-probe microdialysis was used to study interstitial diffusion in the rat brain. A radiolabelled tracer, (3H]mannitol, was continuously infused at different concentrations via a probe acutely implanted into the striatum of an anaesthetized male rat or into a dilute agar gel. Samples were collected by a second probe placed 1 mm away from the first, and the recovered [3H]mannitol was measured by liquid scintillation counting. In the striatum, the delivery of [3H]mannitol was counteracted by its removal from the extracellular space by passive uptake into cells and clearance into the microcirculation, causing the diffusion profile to approach quasi steady-state levels within 2 h. Diffusion data from brain and agar were analysed using a mathematical model. The apparent (effective) diffusion coefficient for [3H]mannitol was D* = 2.9 x 10(-6) cm2/s, the effective volume fraction alpha* = 0.30 and the clearance rate constant kappa= 2.3 x 10(-5)/s. A tortuosity, lambda = 1.81, and penetration distance r = 4.2 mm, were calculated. We conclude that, using dual-probe microdialysis, parameters reflecting geometric and dynamic tissue properties may be obtained using appropriate mathematical analysis. Quantitative dual-probe microdialysis will be valuable in characterizing interstitial diffusion and the clearance processes underpinning volume transmission in the brain.

Quantitative dual-probe microdialysis: mathematical model and analysis.

Steady-state microdialysis is a widely used technique to monitor the concentration changes and distributions of substances in tissues. To obtain more information about brain tissue properties from microdialysis, a dual-probe approach was applied to infuse and sample the radiotracer, [3H]mannitol, simultaneously both in agar gel and in the rat striatum. Because the molecules released by one probe and collected by the other must diffuse through the interstitial space, the concentration profile exhibits dynamic behavior that permits the assessment of the diffusion characteristics in the brain extracellular space and the clearance characteristics. In this paper a mathematical model for dual-probe microdialysis was developed to study brain interstitial diffusion and clearance processes. Theoretical expressions for the spatial distribution of the infused tracer in the brain extracellular space and the temporal concentration at the probe outlet were derived. A fitting program was developed using the simplex algorithm, which finds local minima of the standard deviations between experiments and theory by adjusting the relevant parameters. The theoretical curves accurately fitted the experimental data and generated realistic diffusion parameters, implying that the mathematical model is capable of predicting the interstitial diffusion behavior of [3H]mannitol and that it will be a valuable quantitative tool in dual-probe microdialysis.