Prenatal and postnatal influences on behavioral development in a mouse model of preconceptional stress

Depression during pregnancy is detrimental for the wellbeing of the expectant mother and can exert long-term consequences on the offspring's development and mental health. In this context, both the gestational environment and the postpartum milieu may be negatively affected by the depressive pathology. It is, however, challenging to assess whether the contributions of prenatal and postnatal depression exposure are distinct, interactive, or cumulative, as it is unclear whether antenatal effects are due to direct effects on fetal development or because antenatal symptoms continue postnatally. Preclinical models have sought to answer this question by implementing stressors that induce a depressive-like state in the dams during pregnancy and studying the effects on the offspring. The aim of our present study was to disentangle the contribution of direct stress in utero from possible changes in maternal behavior in a novel model of preconceptional stress based on social isolation rearing (SIR). Using a cross-fostering paradigm in this model, we show that while SIR leads to subtle changes in maternal behavior, the behavioral changes observed in the offspring are driven by a complex interaction between sex, and prenatal and postnatal maternal factors. Indeed, male offspring are more sensitive to the prenatal environment, as demonstrated by behavioral and transcriptional changes driven by their birth mother, while females are likely affected by more complex interactions between the pre and the postpartum milieu, as suggested by the important impact of their surrogate foster mother. Taken together, our findings suggest that male and female offspring have different time-windows and behavioral domains of susceptibility to maternal preconceptional stress, and thus underscore the importance of including both sexes when investigating the mechanisms that mediate the negative consequences of exposure to such stressor.

Mapping of neuronal and glial primary cilia contactome and connectome in the human cerebral cortex

Primary cilia act as antenna receivers of environmental signals and enable effective neuronal or glial responses. Disruption of their function is associated with circuit disorders. To understand the signals these cilia receive, we comprehensively mapped cilia's contacts within the human cortical connectome using serial-section EM reconstruction of a 1 mm3 cortical volume, spanning the entire cortical thickness. We mapped the "contactome" of cilia emerging from neurons and astrocytes in every cortical layer. Depending on the layer and cell type, cilia make distinct patterns of contact. Primary cilia display cell-type- and layer-specific variations in size, shape, and microtubule axoneme core, which may affect their signaling competencies. Neuronal cilia are intrinsic components of a subset of cortical synapses and thus a part of the connectome. This diversity in the structure, contactome, and connectome of primary cilia endows each neuron or glial cell with a unique barcode of access to the surrounding neural circuitry.

Symptomatic and preventive effects of the novel phosphodiesterase-9 inhibitor BI 409306 in an immune-mediated model of neurodevelopmental disorders

BI 409306, a phosphodiesterase-9 inhibitor under development for treatment of schizophrenia and attenuated psychosis syndrome (APS), promotes synaptic plasticity and cognition. Here, we explored the effects of BI 409306 treatment in the polyriboinosinic-polyribocytidilic acid (poly[I:C])-based mouse model of maternal immune activation (MIA), which is relevant to schizophrenia and APS. In Study 1, adult offspring received BI 409306 0.2, 0.5, or 1 mg/kg or vehicle to establish an active dose. In Study 2, adult offspring received BI 409306 1 mg/kg and/or risperidone 0.025 mg/kg, risperidone 0.05 mg/kg, or vehicle, to evaluate BI 409306 as add-on to standard therapy for schizophrenia. In Study 3, offspring received BI 409306 1 mg/kg during adolescence only, or continually into adulthood to evaluate preventive effects of BI 409306. We found that BI 409306 significantly mitigated MIA-induced social interaction deficits and amphetamine-induced hyperlocomotion, but not prepulse inhibition impairments, in a dose-dependent manner (Study 1). Furthermore, BI 409306 1 mg/kg alone or in combination with risperidone 0.025 mg/kg significantly reversed social interaction deficits and attenuated amphetamine-induced hyperlocomotion in MIA offspring (Study 2). Finally, we revealed that BI 409306 1 mg/kg treatment restricted to adolescence prevented adult deficits in social interaction, whereas continued treatment into adulthood also significantly reduced amphetamine-induced hyperlocomotion (Study 3). Taken together, our findings suggest that symptomatic treatment with BI 409306 can restore social interaction deficits and dopaminergic dysfunctions in a MIA model of neurodevelopmental disruption, lending preclinical support to current clinical trials of BI 409306 in patients with schizophrenia. Moreover, BI 409306 given during adolescence has preventive effects on adult social interaction deficits in this model, supporting its use in people with APS.

Oral application of clozapine-N-oxide using the micropipette-guided drug administration (MDA) method in mouse DREADD systems

The designer receptor exclusively activated by designer drugs (DREADD) system is one of the most widely used chemogenetic techniques to modulate the activity of cell populations in the brains of behaving animals. DREADDs are activated by acute or chronic administration of their ligand, clozapine-N-oxide (CNO). There is, however, a current lack of a non-invasive CNO administration technique that can control for drug timing and dosing without inducing substantial distress for the animals. Here, we evaluated whether the recently developed micropipette-guided drug administration (MDA) method, which has been used as a non-invasive and minimally stressful alternative to oral gavages, may be applied to administer CNO orally to activate DREADDs in a dosing- and timing-controlled manner. Unlike standard intraperitoneal injections, administration of vehicle substances via MDA did not elevate plasma levels of the major stress hormone, corticosterone, and did not attenuate exploratory activity in the open field test. At the same time, however, administration of CNO via MDA or intraperitoneally was equally efficient in activating hM3D_Gq-expressing neurons in the medial prefrontal cortex, as evident by time-dependent increases in mRNA levels of neuronal immediate early genes (cFos, Arc and Zif268) and cFos-immunoreactive neurons. Compared to vehicle given via MDA, oral administration of CNO via MDA was also found to potently increase locomotor activity in mice that express hM3D_Gq in prefrontal neurons. Taken together, our study confirms the effectiveness of CNO given orally via MDA and provides a novel method for non-stressful, yet well controllable CNO treatments in mouse DREADD systems.

Behavioral, neuroanatomical, and molecular correlates of resilience and susceptibility to maternal immune activation

Infectious or noninfectious maternal immune activation (MIA) is an environmental risk factor for psychiatric and neurological disorders with neurodevelopmental etiologies. Whilst there is increasing evidence for significant health consequences, the effects of MIA on the offspring appear to be variable. Here, we aimed to identify and characterize subgroups of isogenic mouse offspring exposed to identical MIA, which was induced in C57BL6/N mice by administration of the viral mimetic, poly(I:C), on gestation day 12. Cluster analysis of behavioral data obtained from a first cohort containing >150 MIA and control offspring revealed that MIA offspring could be stratified into distinct subgroups that were characterized by the presence or absence of multiple behavioral dysfunctions. The two subgroups also differed in terms of their transcriptional profiles in cortical and subcortical brain regions and brain networks of structural covariance, as measured by ex vivo structural magnetic resonance imaging (MRI). In a second, independent cohort containing 50 MIA and control offspring, we identified a subgroup of MIA offspring that displayed elevated peripheral production of innate inflammatory cytokines, including IL-1β, IL-6, and TNF-α, in adulthood. This subgroup also showed significant impairments in social approach behavior and sensorimotor gating, whereas MIA offspring with a low inflammatory cytokine status did not. Taken together, our results highlight the existence of subgroups of MIA-exposed offspring that show dissociable behavioral, transcriptional, brain network, and immunological profiles even under conditions of genetic homogeneity. These data have relevance for advancing our understanding of the variable neurodevelopmental effects induced by MIA and for biomarker-guided approaches in preclinical psychiatric research.

Preclinical validation of the micropipette-guided drug administration (MDA) method in the maternal immune activation model of neurodevelopmental disorders

Pharmacological treatments in laboratory rodents remain a cornerstone of preclinical psychopharmacological research and drug development. There are numerous ways in which acute or chronic pharmacological treatments can be implemented, with each method having certain advantages and drawbacks. Here, we describe and validate a novel treatment method in mice, which we refer to as the micropipette-guided drug administration (MDA) procedure. This administration method is based on a sweetened condensed milk solution as a vehicle for pharmacological substances, which motivates the animals to consume vehicle and/or drug solutions voluntarily in the presence of the experimenter. In a proof-of-concept study, we show that the pharmacokinetic profiles of the atypical antipsychotic drug, risperidone, were similar whether administered via the MDA procedure or via the conventional oral gavage method. Unlike the latter, however, MDA did not induce the stress hormone, corticosterone. Furthermore, we assessed the suitability and validity of the MDA method in a mouse model of maternal immune activation, which is frequently used as a model of immune-mediated neurodevelopmental disorders. Using this model, we found that chronic treatment (>4 weeks, once per day) with risperidone via MDA led to a dose-dependent mitigation of MIA-induced social interaction deficits and amphetamine hypersensitivity. Taken together, the MDA procedure described herein represents a novel pharmacological administration method for per os treatments in mice that is easy to implement, cost effective, non-invasive, and less stressful for the animals than conventional oral gavage methods.

Dependency of prepulse inhibition deficits on baseline startle reactivity in a mouse model of the human 22q11.2 microdeletion syndrome

Hemizygous microdeletion at the chromosomal locus 22q11.2 is a copy number variation with strong genetic linkage to schizophrenia and related disorders. This association, along with its phenotypic overlap with the 22q11.2 microdeletion syndrome, has motivated the establishment of Df[h22q11]/+ mice, in which the human 22q11.2 orthologous region is deleted. Previous investigations using this model showed the presence of reduced prepulse inhibition (PPI) of the acoustic startle reflex, a form of sensorimotor gating known to be impaired in a number of psychiatric disorders. Concomitantly to reduced PPI, however, Df[h22q11]/+ mice are also characterized by a robust increase in baseline startle reactivity, which may complicate or confound the interpretation of PPI. Therefore, the present study re-examined the relationship between acoustic startle reactivity and PPI in this mouse model. We found that while PPI is reduced in Df[h22q11]/+ mice when using its relative indexation (ie, % PPI), this deficit is no longer apparent when using the absolute quantification, that is, the direct comparison between pulse-alone and prepulse-plus-pulse conditions with successively increasing prepulse intensities. We further identified marked negative correlations between % PPI and startle reactivity in Df[h22q11]/+ mice. Moreover, when stratifying Df[h22q11]/+ mice into subgroups displaying low- and high-startle reactivity, only the latter subgroup displayed a significant reduction in % PPI. Collectively, our data suggest that alterations in baseline startle reactivity can confound the outcomes and interpretation of PPI in this mouse model of the human 22q11.2 microdeletion syndrome.

Electrophysiological and behavioral phenotype of insulin receptor defective mice

The olfactory bulb expresses one of the highest levels of insulin found in the brain. A high level of expression of the concomitant insulin receptor (IR) kinase is also retained in this brain region, even in the adult. We have previously demonstrated in a heterologous system that insulin modulates the voltage-dependent potassium channel, Kv1.3, through tyrosine phosphorylation of three key residues in the amino and carboxyl terminus of the channel protein. Phosphorylation also induces current suppression of the Kv1.3-contributed current in cultured olfactory bulb neurons (OBNs) of rodents. In order to explore the behavioral importance of this kinase-induced modulation of the channel for the olfactory ability of the animal, mice with a targeted-gene deletion of the insulin receptor were electrophysiologically and behaviorally characterized. Mice heterozygous for the insulin receptor kinase (IR+/-) gene performed the same as wild-type (+/+) mice when challenged with a traditional, non-learning-based task to test gross anosmia. There was also no significant difference across the two genotypes in tests designed to measure exploratory behavior or in a battery of systems physiology experiments designed to assess metabolic energy usage (locomotion, ingestive behaviors, weight, oxygen consumption, and respiratory quotient). Object memory recognition tests suggest that IR+/- mice have an impairment in recognition of familiarized objects; IR+/- mice demonstrate poor performance for both short-term (1 h) and long-term (24 h) memory tests in comparison to that of wild-type mice. Electrophysiological experiments indicate that mitral cell neurons cultured from both heterozygous and homozygous-null mice (IR+/- and IR-/-) have an decreased peak current amplitude compared with that recorded for wild-type (+/+) animals matched for days in vitro (DIV). These data indicate that the loss of one allele of the IR kinase gene modifies the electrical phenotype of the mitral cell neurons in the olfactory bulb without a change in gross olfactory ability. Given our findings that there are no significant changes in metabolic balance of the IR (+/-) mice but some impairment in memory retention, future experiments testing for specific olfactory behaviors or functional deficits in IR-/+ mice models of diabetes will need to either be tasks that do not require learning or will require a different model (such as diet-induced diabetes) that may evoke a stronger phenotype.

The study of early human embryos using interactive 3-dimensional computer reconstructions

Tracings of serial histological sections from 4 human embryos at different Carnegie stages were used to create 3-dimensional (3D) computer models of the developing heart. The models were constructed using commercially available software developed for graphic design and the production of computer generated virtual reality environments. They are available as interactive objects which can be downloaded via the World Wide Web. This simple method of 3D reconstruction offers significant advantages for understanding important events in morphological sciences.

Engraftment of human hematopoietic precursor cells with secondary transfer potential in SCID-hu mice

Human fetal bone fragments implanted subcutaneously in immunodeficient (SCID) mice maintain active human hematopoiesis. In this study, we show that this human hematopoietic microenvironment supports the engraftment and differentiation of HLA-mismatched, CD34+ primitive hematopoietic progenitor cells isolated from fetal and adult human bone marrow (BM). The BM CD34+ cells were depleted of CD2, CD14, CD15, CD16, glycophorin A, and CD19 lineage-committed cells (CD34+Lin-). Donor cell engraftment was manifested by the presence of B (CD19+) and myeloid (CD33+) cells of donor HLA phenotype. Successful engraftment was observed as early as 4 weeks after fetal BM donor cell injection and sustained for at least 12 weeks, with engraftment success rates of 100% (11/11 grafts) and 92% (11/12 grafts) at 8 and 12 weeks, respectively. Mixed BM chimerism of donor and endogenous cells was consistently observed in SCID-hu bones successfully engrafted with HLA-mismatched CD34+Lin- donor cells. Preconditioning of the SCID-hu bone with a single dose of sublethal (350 rad) whole body irradiation (WBI) immediately before cell injection enhanced the repopulation of the bone grafts with donor cells and, in some instances, resulted in complete repopulation. After WBI, as few as 500 fetal bone marrow CD34+Lin- cells injected in the human bone grafts resulted in donor-derived hematopoiesis. Donor progenitor cells recovered from the SCID-hu bone grafts 8 weeks postinjection had the capacity to repopulate secondary groups of HLA-disparate fetal human bones in SCID-hu mice with B and myeloid cells as well as CD34+ cells in some recipients. In addition, these cells repopulated fetal human thymus fragments in SCID mice with donor thymocytes including immature CD4+CD8+ and mature CD4+CD8- as well as CD4-CD8+ subsets. These results indicate that the fetal human bone implants of SCID-hu mice can support the maintenance of a cell population that has both multilineage potential and repopulating potential for periods of time as long as 16 weeks. The SCID-hu bone model consistently supported the engraftment of both fetal and adult CD34+Lin- cells without the administration of exogenous human cytokines to these animals. This model is currently being used to permit the isolation and characterization of candidate human hematopoietic stem cells (HSCs) and provide important information critical for human HSC therapy in humans.

Celsus on human vivisection at Ptolemaic Alexandria

A method for obtaining localized high-resolution magnetic resonance (MR) images of the eye and orbit is demonstrated. The method uses modified surface receiver coils placed immediately adjacent to the anatomy to detect the MR signal. Surface coils provide enhanced sensitivity for imaging voxels close to the surface of the body while limiting the received patient-generated noise. The resulting improvement in signal-to-noise ratio allows for a reduction in the imaging voxel size to about 0.5 × 0.5 × 5 mm in scan times of 3.4–5 min. At this level of resolution, anatomic detail in the orbital region previously unobservable in MR images is seen.

On medications for burns in classical antiquity

Egyptian, Greek, Roman, and early Byzantine medical pharmaceutical works show a fairly sophisticated array of simple and compound remedies for burns and scalds. Chief among ancient writings that provide specific botany, minerals, and similar substances used in burn treatment are several Egyptian papyri, the Hippocratic On Wounds, and writings by Celsus, Dioscorides, Pliny the Elder, and Paul of Aegina. Over 70 plants and minerals are identified according to modern nomenclatures. The ancients sought especially those ingredients that would promote rapid healing with a minimum of scarring.