Clonally expanded B cells in multiple sclerosis bind EBV EBNA1 and GlialCAM.

Multiple sclerosis (MS) is a heterogenous autoimmune disease in which autoreactive lymphocytes attack the myelin sheath of the central nervous system. B lymphocytes in the cerebrospinal fluid (CSF) of patients with MS contribute to inflammation and secrete oligoclonal immunoglobulins1,2. Epstein-Barr virus (EBV) infection has been epidemiologically linked to MS, but its pathological role remains unclear3. Here we demonstrate high-affinity molecular mimicry between the EBV transcription factor EBV nuclear antigen 1 (EBNA1) and the central nervous system protein glial cell adhesion molecule (GlialCAM) and provide structural and in vivo functional evidence for its relevance. A cross-reactive CSF-derived antibody was initially identified by single-cell sequencing of the paired-chain B cell repertoire of MS blood and CSF, followed by protein microarray-based testing of recombinantly expressed CSF-derived antibodies against MS-associated viruses. Sequence analysis, affinity measurements and the crystal structure of the EBNA1-peptide epitope in complex with the autoreactive Fab fragment enabled tracking of the development of the naive EBNA1-restricted antibody to a mature EBNA1-GlialCAM cross-reactive antibody. Molecular mimicry is facilitated by a post-translational modification of GlialCAM. EBNA1 immunization exacerbates disease in a mouse model of MS, and anti-EBNA1 and anti-GlialCAM antibodies are prevalent in patients with MS. Our results provide a mechanistic link for the association between MS and EBV and could guide the development of new MS therapies.

Considerations about risk of ongoing distress: what can we learn from repeat screening?

The importance of routine distress screening in cancer patients is widely acknowledged, though non-compliance with screening protocols is common. Cited reasons for non-adherence include lack of time and expertise and concerns about the resources associated with the identification and management of clinically relevant distress. This commentary examines changes in distress among people with cancer who participated in a tele-based psychosocial intervention, from the point of initial distress screening to 12 months after commencing the intervention. The goal is to contribute to the discussion about the potential infrastructure requirements of implementing screening programs among screening 'hesitant' cancer care services. Secondary analysis showed a general downward distress trajectory though the greatest reduction occurred between recruitment and baseline and before receiving a low-intensity psychosocial intervention (ß = - 1.84, 95% CI - 2.12, - 1.56). While acknowledging transience of distress in some patients, our results support the possible therapeutic benefit of assessing and validating individuals' distress in the hope of preventing the development of more overt health problems associated with undiagnosed and untreated symptoms.

Biochemically altered myelin triggers autoimmune demyelination.

Although immune attack against central nervous system (CNS) myelin is a central feature of multiple sclerosis (MS), its root cause is unresolved. In this report, we provide direct evidence that subtle biochemical modifications to brain myelin elicit pathological immune responses with radiological and histological properties similar to MS lesions. A subtle myelinopathy induced by abbreviated cuprizone treatment, coupled with subsequent immune stimulation, resulted in lesions of inflammatory demyelination. The degree of myelin injury dictated the resulting immune response; biochemical damage that was too limited or too extensive failed to trigger overt pathology. An inhibitor of peptidyl arginine deiminases (PADs), enzymes that alter myelin structure and correlate with MS lesion severity, mitigated pathology even when administered only during the myelin-altering phase. Moreover, cultured splenocytes were reactive against donor myelin isolates, a response that was substantially muted when splenocytes were exposed to myelin from donors treated with PAD inhibitors. By showing that a primary biochemical myelinopathy can trigger secondary pathological inflammation, "cuprizone autoimmune encephalitis" potentially reconciles conflicting theories about MS pathogenesis and provides a strong rationale for investigating myelin as a primary target for early, preventative therapy.

Repopulation of T, B, and NK cells following alemtuzumab treatment in relapsing-remitting multiple sclerosis.

OBJECTIVE: To characterize long-term repopulation of peripheral immune cells following alemtuzumab-induced lymphopenia in relapsing-remitting MS (RRMS), with a focus on regulatory cell types, and to explore associations with clinical outcome measures. METHODS: The project was designed as a multicenter add-on longitudinal mechanistic study for RRMS patients enrolled in CARE-MS II, CARE-MS II extension at the University of Southern California and Stanford University, and an investigator-initiated study conducted at the Universities of British Columbia and Chicago. Methods involved collection of blood at baseline, prior to alemtuzumab administration, and at months 5, 11, 17, 23, 36, and 48 post-treatment. T cell, B cell, and natural killer (NK) cell subsets, chemokine receptor expression in T cells, in vitro cytokine secretion patterns, and regulatory T cell (Treg) function were assessed. Clinical outcomes, including expanded disability status score (EDSS), relapses, conventional magnetic resonance imaging (MRI) measures, and incidents of secondary autoimmunity were tracked. RESULTS: Variable shifts in lymphocyte populations occurred over time in favor of CD4+ T cells, B cells, and NK cells with surface phenotypes characteristic of regulatory subsets, accompanied by reduced ratios of effector to regulatory cell types. Evidence of increased Treg competence was observed after each treatment course. CD4+ and CD8+ T cells that express CXCR3 and CCR5 and CD8+ T cells that express CDR3 and CCR4 were also enriched after treatment, indicating heightened trafficking potential in activated T cells. Patterns of repopulation were not associated with measures of clinical efficacy or secondary autoimmunity, but exploratory analyses using a random generalized estimating equation (GEE) Poisson model provide preliminary evidence of associations between pro-inflammatory cell types and increased risk for gadolinium (Gd+) enhancing lesions, while regulatory subsets were associated with reduced risk. In addition, the risk for T2 lesions correlated with increases in CD3+CD8+CXCR3+ cells. CONCLUSIONS: Lymphocyte repopulation after alemtuzumab treatment favors regulatory subsets in the T cell, B cell, and NK cell compartments. Clinical efficacy may reflect the sum of interactions among them, leading to control of potentially pathogenic effector cell types. Several immune measures were identified as possible biomarkers of lesion activity. Future studies are necessary to more precisely define regulatory and effector subsets and their contributions to clinical efficacy and risk for secondary autoimmunity in alemtuzumab-treated patients, and to reveal new insights into mechanisms of immunopathogenesis in MS. TRIAL REGISTRATION: Parent trials for this study are registered with ClinicalTrials.gov: CARE-MS II: NCT00548405, CARE-MS II extension: NCT00930553 and ISS: NCT01307332.

Tandospirone, a Partial 5-HT1A Receptor Agonist, Administered Systemically or Into Anterior Cingulate Attenuates Repetitive Behaviors in Shank3B Mice.

BACKGROUND: Several cases of autism spectrum disorder have been linked to mutations in the SHANK3 gene. Haploinsufficiency of the SHANK3 gene contributes to Phelan-McDermid syndrome, which often presents an autism spectrum disorder phenotype along with moderate to severe intellectual disability. A SHANK3 gene deletion in mice results in elevated excitation of cortical pyramidal neurons that alters signaling to other brain areas. Serotonin 1A receptors are highly expressed on layer 2 cortical neurons and are known to have inhibitory actions. Serotonin 1A receptor agonist treatment in autistic cases with SHANK3 mutations and possibly other cases may restore excitatory and inhibitory balance that attenuates core symptoms. METHODS: A series of experiments investigated the effects of acute tandospirone treatment on spatial learning and self-grooming, subchronic treatment of tandospirone on self-grooming behavior, and the effect of tandospirone infusion into the anterior cingulate on self-grooming behavior. RESULTS: Only male Shank3B+/- mice exhibited a spatial learning deficit and elevated self-grooming. Acute i.p. injection of tandospirone, 0.01 and 0.06 mg/kg in male Shank3B+/- mice, attenuated a spatial acquisition deficit by improving sensitivity to positive reinforcement and reduced elevated self-grooming behavior. Repeated tandospirone (0.06 mg/kg) treatment attenuated elevated self-grooming behavior in male Shank3B+/- mice. Tandospirone injected into the anterior cingulate/premotor area reduced self-grooming behavior in male Shank3B+/- mice. CONCLUSIONS: These results suggest that stimulation of cortical serotonin 1A receptors may reduce repetitive behaviors and cognitive impairments as observed in autism spectrum disorder, possibly by attenuating an excitation/inhibition imbalance. Further, tandospirone may serve as a treatment in autism spectrum disorder and other disorders associated with SHANK3 mutations.

Prostate cancer survivorship priorities for men and their partners: Delphi consensus from a nurse specialist cohort.

AIMS & OBJECTIVES: To describe the prostate cancer survivorship experience and priorities from the perspective of prostate cancer specialist nurses. BACKGROUND: Specialist nurses are providing long-term survivorship care to men and their partners however, few prostate cancer survivorship interventions are effective and priorities for nurse-led survivorship care are poorly understood. DESIGN: A three-round modified Delphi approach. METHODS: The study was conducted between 1 December 2018 and 28 February 2019 to develop a consensus view from an expert nurse cohort (43 prostate cancer specialist nurses: 90% response). First, participants described men's prostate cancer survivorship experience and priorities for improving care for men and partners. In subsequent rounds, participants identified key descriptors of the survivorship experience; rated priorities for importance and feasibility; and identified a top priority action for men and for partners. Thematic analysis and descriptive statistics were applied. Guidelines for Reporting Reliability and Agreement Studies informed the conduct of the study. RESULTS: Prostate cancer specialist nurses characterised the prostate cancer survivorship experience of men as under-resourced, disjointed and distressing. In all, 11 survivorship priorities for men and three for partners were identified within five broad areas: capacity building; care coordination; physical and psychosocial care; community awareness and early detection; and palliative care. However, feasibility for individual items was frequently described as low. CONCLUSION: Internationally, prostate cancer survivorship care for men and their partners requires urgent action to meet future need and address gaps in capacity and care coordination. Low feasibility of survivorship priorities may reflect translational challenges related to capacity. Prostate cancer survivorship care guidelines connected to practice priorities are urgently needed. RELEVANCE TO CLINICAL PRACTICE: These findings address key gaps in the evidence for developing national nurse-led prostate cancer survivorship priorities. These priorities can be used to inform survivorship guidelines including nursing care for men with prostate cancer and their partners.

Prevalence of advance care directives in the community: a telephone survey of three Australian States.

BACKGROUND: The community prevalence of advance care directives (ACD) is low despite known benefits of advance care planning for patients, families and health professionals. AIM: To determine the community prevalence of instructional and appointing ACD in New South Wales, Victoria and Queensland and factors associated with completion of these documents. METHODS: A telephone survey of adults living in New South Wales, Victoria and Queensland (n = 1175) about completion of instructional ACD (making their own decisions about future healthcare) and appointing ACD (appointing another to decide). Quota sampling occurred based on population size by state, gender and age, with oversampling in smaller jurisdictions (Victoria and Queensland). RESULTS: Overall response rate was 33%. Six per cent of respondents reported completing an instructional ACD while 12% reported completing an appointing ACD. Female gender, higher educational level, personal experience of a major health scare and being widowed were significant predictors of completing an instructional ACD. Older age, higher educational level and being widowed were significant predictors of completing an appointing ACD. CONCLUSIONS: Despite long-standing efforts to increase advance care planning, community prevalence of ACD remains low, particularly for instructional ACD. This study found some different predictors for instructional ACD compared with appointing ACD, and also a potential role for experiential factors in triggering uptake. These findings suggest supplementing general community awareness campaigns with more nuanced and targeted efforts to improve ACD completion.

Community Knowledge of Law on End-of-life Decision-making: An Australian Telephone Survey.

The law has a clear role to play in supporting patients and their substitute decision-makers (SDMs) to be involved in end-of-life (EOL) decision-making. Although existing literature suggests that knowledge of EOL law is variable among health professionals, there is little information about the extent and sources of such knowledge within the general community. A telephone survey of a representative sample of adults in three Australian States used six case scenarios to examine the extent to which adults know their legal duties, rights and powers as patients or SDMs; the sources from which people derive relevant legal knowledge; experiences of EOL decision-making; and individual characteristics associated with levels of knowledge. The results show considerable variation in levels of legal knowledge dependent primarily of the area of decision-making presented, some sizeable gaps in people's knowledge of EOL law, and varied awareness of how to access appropriate information on this subject. This study points to the need to increase community legal literacy around EOL decision-making, enhance awareness of the role of law in these circumstances and promote the availability of reliable and accessible information on the law at the time when it is needed.

Community knowledge of law at the end of life: availability and accessibility of web-based resources.

Objective The aim of the present study was to identify online resources community members may access to inform themselves about their legal duties and rights in end-of-life decision making. Methods Resource mapping identified online resources that members of the public in New South Wales, Victoria and Queensland are likely to identify, and assessed the ease or difficulty in locating them. Resources were then critically analysed for accessibility of language and format using the Patient Education Materials Assessment Tool (PEMAT). Results Identified resources differed considerably based on whether search terms identified by community members or experts were used. Most resources focused on advance directives, enduring powers of attorney and substitute decision making. Relatively few provided information about legal duties (e.g. powers and responsibilities of substitute decision makers) or resolving conflict with health practitioners. Accessibility (understandability and actionability) of resource content varied. Conclusions Although numerous resources on end-of-life law are available online, community members may not be able to identify relevant resources or find resource content accessible. What is known about the topic? Research on participation by patients in decision making about their treatment has focused primarily on medical rather than legal knowledge. What does this paper add? The present study investigated which online resources community members may access to inform themselves about the law on end-of-life decision making. The resources identified were analysed for ease of location and content accessibility. What are the implications for practitioners? Authors of online resources on end-of-life decision making should consider whether their resources can be: (1) identified by search terms used by the public; (2) understood by a general audience; and (3) readily used to promote reader action.

IFN-ß treatment requires B cells for efficacy in neuroautoimmunity.

IFN-ß remains the most widely prescribed treatment for relapsing remitting multiple sclerosis. Despite widespread use of IFN-ß, the therapeutic mechanism is still partially understood. Particularly, the clinical relevance of increased B cell activity during IFN-ß treatment is unclear. In this article, we show that IFN-ß pushes some B cells into a transitional, regulatory population that is a critical mechanism for therapy. IFN-ß treatment increases the absolute number of regulatory CD19(+)CD24(++)CD38(++) transitional B cells in peripheral blood relative to treatment-naive and Copaxone-treated patients. In addition, we found that transitional B cells from both healthy controls and IFN-ß-treated MS patients are potent producers of IL-10, and that the capability of IFN-ß to induce IL-10 is amplified when B cells are stimulated. Similar changes are seen in mice with experimental autoimmune encephalomyelitis. IFN-ß treatment increases transitional and regulatory B cell populations, as well as IL-10 secretion in the spleen. Furthermore, we found that IFN-ß increases autoantibody production, implicating humoral immune activation in B cell regulatory responses. Finally, we demonstrate that IFN-ß therapy requires immune-regulatory B cells by showing that B cell-deficient mice do not benefit clinically or histopathologically from IFN-ß treatment. These results have significant implications for the diagnosis and treatment of relapsing remitting multiple sclerosis.

Economic evaluation of a psychological intervention for high distress cancer patients and carers: costs and quality-adjusted life years.

OBJECTIVE: This study compared the cost-effectiveness of a psychologist-led, individualised cognitive behavioural intervention (PI) to a nurse-led, minimal contact self-management condition for highly distressed cancer patients and carers. METHODS: This was an economic evaluation conducted alongside a randomised trial of highly distressed adult cancer patients and carers calling cancer helplines. Services used by participants were measured using a resource use questionnaire, and quality-adjusted life years were measured using the assessment of quality of life - eight-dimension - instrument collected through a computer-assisted telephone interview. The base case analysis stratified participants based on the baseline score on the Brief Symptom Inventory. Incremental cost-effectiveness ratio confidence intervals were calculated with a nonparametric bootstrap to reflect sampling uncertainty. The results were subjected to sensitivity analysis by varying unit costs for resource use and the method for handling missing data. RESULTS: No significant differences were found in overall total costs or quality-adjusted life years (QALYs) between intervention groups. Bootstrapped data suggest the PI had a higher probability of lower cost and greater QALYs for both carers and patients with high distress at baseline. For patients with low levels of distress at baseline, the PI had a higher probability of greater QALYs but at additional cost. Sensitivity analysis showed the results were robust. CONCLUSIONS: The PI may be cost-effective compared with the nurse-led, minimal contact self-management condition for highly distressed cancer patients and carers. More intensive psychological intervention for patients with greater levels of distress appears warranted. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Distinguishing features of depression in dementia from primary psychiatric disease.

Depression is a common and devastating neuropsychiatric symptom in the elderly and in patients with dementia. In particular, nearly 80% of patients with Alzheimer's Disease dementia experience depression during disease development and progression. However, it is unknown whether the depression in patients with dementia shares the same molecular mechanisms as depression presenting as primary psychiatric disease or occurs and persists through alternative mechanisms. In this review, we discuss how the clinical presentation and treatment differ between depression in dementia and as a primary psychiatric disease, with a focus on major depressive disorder. Then, we hypothesize several molecular mechanisms that may be unique to depression in dementia such as neuropathological changes, inflammation, and vascular events. Finally, we discuss existing issues and future directions for investigation and treatment of depression in dementia.

Behavioral and Molecular Characterization of Prenatal Stress Effects on the C57BL/6J Genetic Background for the Study of Autism Spectrum Disorder.

Stress-inducing events during pregnancy are associated with aberrant neurodevelopment resulting in adverse psychiatric outcomes, including autism spectrum disorder (ASD). While numerous preclinical models for the study of ASD are frequently generated using C57BL/6J mice, few studies have investigated the effects of prenatal stress on this genetic background. In the current manuscript, we stressed C57BL/6 dams during gestation and examined numerous behavioral and molecular endophenotypes in the adult male and female offspring to characterize the resultant phenotype as compared with offspring born from nonstressed (NS) dams. Adult mice born from prenatal restraint stressed (PRS) dams demonstrated reduced sociability and reciprocal social interaction along with increased marble burying behaviors relative to mice born from nonstressed control dams. Differential expression of genes related to excitatory and inhibitory neurotransmission was evaluated in the medial prefrontal cortex, amygdala, hippocampus, nucleus accumbens and caudate putamen via qRT-PCR. The male PRS mouse behavioral phenotype coincided with aberrant expression of glutamate and GABA marker genes (e.g., Grin1, Grin2b, Gls, Gat1, Reln) in neural substrates of social behavior. Rescue of the male PRS sociability deficit by a known antipsychotic with epigenetic properties (i.e., clozapine (5 mg/kg) + 18 hr washout) indicated possible epigenetic regulation of genes that govern sociability. Clozapine treatment increased the expression levels of genes involved in DNA methylation, histone methylation, and histone acetylation in the nucleus accumbens. Identification of etiology-specific mechanisms underlying clinically relevant behavioral phenotypes may ultimately provide novel therapeutic interventions for the treatment of psychiatric disorders including ASD.

Unique transcriptional signatures correlate with behavioral and psychological symptom domains in Alzheimer's disease.

Despite the significant burden, cost, and worse prognosis of Alzheimer's disease (AD) with behavioral and psychological symptoms of dementia (BPSD), little is known about the molecular causes of these symptoms. Using antemortem assessments of BPSD in AD, we demonstrate that individual BPSD can be grouped into 4 domain factors in our cohort: affective, apathy, agitation, and psychosis. Then, we performed a transcriptome-wide analysis for each domain utilizing bulk RNA-seq of post-mortem anterior cingulate cortex (ACC) tissues. Though all 4 domains are associated with a predominantly downregulated pattern of hundreds of differentially expressed genes (DEGs), most DEGs are unique to each domain, with only 22 DEGs being common to all BPSD domains, including TIMP1. Weighted gene co-expression network analysis (WGCNA) yielded multiple transcriptional modules that were shared between BPSD domains or unique to each domain, and NetDecoder was used to analyze context-dependent information flow through the biological network. For the agitation domain, we found that all DEGs and a highly associated transcriptional module were functionally enriched for ECM-related genes including TIMP1, TAGLN, and FLNA. Another unique transcriptional module also associated with the agitation domain was enriched with genes involved in post-synaptic signaling, including DRD1, PDE1B, CAMK4, and GABRA4. By comparing context-dependent changes in DEGs between cases and control networks, ESR1 and PARK2 were implicated as two high-impact genes associated with agitation that mediated significant information flow through the biological network. Overall, our work establishes unique targets for future study of the biological mechanisms of BPSD and resultant drug development.

Clinical features of neurotoxicity after CD19 CAR T-cell therapy in mantle cell lymphoma.

ABSTRACT: CD19 chimeric antigen receptor (CAR) T-cell therapy has proven highly effective for treating relapsed/refractory mantle cell lymphoma (MCL). However, immune effector cell-associated neurotoxicity syndrome (ICANS) remains a significant concern. This study aimed to evaluate the clinical, radiological, and laboratory correlatives associated with ICANS development after CD19 CAR T-cell therapy in patients with MCL. All patients (N = 26) who received standard-of-care brexucabtagene autoleucel until July 2022 at our institution were evaluated. Laboratory and radiographic correlatives including brain magnetic resonance imaging (MRI) and electroencephalogram (EEG) were evaluated to determine the clinical impact of ICANS. Seventeen (65%) patients experienced ICANS after treatment, with a median onset on day 6. Ten (38%) patients experienced severe (grade ≥3) ICANS. All patients with ICANS had antecedent cytokine release syndrome (CRS), but no correlation was observed between ICANS severity and CRS grade. Overall, 92% of EEGs revealed interictal changes; no patients experienced frank seizures because of ICANS. In total, 86% of patients with severe ICANS with postinfusion brain MRIs demonstrated acute neuroimaging findings not seen on pretreatment MRI. Severe ICANS was also associated with higher rates of cytopenia, coagulopathy, increased cumulative steroid exposure, and prolonged hospitalization. However, severe ICANS did not affect treatment outcomes of patients with MCL. Severe ICANS is frequently associated with a range of postinfusion brain MRI changes and abnormal EEG findings. Longer hospitalization was observed in patients with severe ICANS, especially those with abnormal acute MRI or EEG findings, but there was no discernible impact on overall treatment response and survival.

Psychological Stress and skin aging: a review of possible mechanisms and potential therapies.

The link between psychological stress and aging is intuitive although the underlying mechanisms are not well defined. Evidence suggests that chronic psychological stress stimulates the autonomic nervous system, renin-angiotensin system, and the hypothalamic-pituitary-adrenal axis when the body attempts to resolve perceived threats to homeostasis. Prolonged activation of these pathways can result in chronic immune dysfunction, increased production of reactive oxygen species, and DNA damage, which are known to contribute to the again of skin and other tissues. Despite the lack of conclusive evidence directly linking psychological stress to skin aging, mechanisms by which stress leads to immune dysfunction, oxidative radicals, and ultimately DNA damage via neuronal, endocrine, and immune modulation may present a possible intervention for skin aging. In addition to the wide array of anti-oxidant therapies being developed to combat aging, the topical use of beta-blockers such as timolol, angiotensin receptor blockers such as valsartan, glucocorticoid blockers such as mifepristone, and cholinergic modulators including botulinum toxin, might be potential therapeutic strategies to prevent skin aging. Given the current understanding of these pathways, it would be premature to utilize such modalities for prevention of skin aging at this time, but future research into this type of topical pharmacologic anti-aging intervention may be promising.

An update of dermatologist usage of the Physician Quality Reporting System in Colorado for 2011.

The Physician Quality Reporting System (PQRS) was established in 2006 by the Centers for Medicare and Medicaid Services (CMS) as part of an incentive process to improve healthcare preventive practices. As of 2011, there were 235 PQRS measures but only three specific to skin diseases, specifically melanoma. To measure current usage of the PQRS among dermatologists in Colorado, a survey was distributed at the 2011 Colorado Dermatological Society Meeting. Of the 120 physician attendees, 60 responded, yielding a response rate of 50%. Compared with responses from a similar 2010 survey, a significantly higher number of physicians are using PQRS, as well as E-prescribing and EHR systems. This is likely owing to the fact that CMS will require mandatory reporting of these measures in 2015. Respondents from the current survey commented that a major hurdle to PQRS reporting is the inability to submit data through existing EHR or billing systems. Currently, CMS requires PQRS reporting through a designated registry such as that provided by the AAD. Some practices have opted to report metrics such as tobacco and alcohol screening, since these can be reported through their billing systems. The results suggest structural improvements in the PQRS reporting system could improve compliance.

Seeking the Amygdala: Novel Use of Diffusion Tensor Imaging to Delineate the Basolateral Amygdala.

The amygdaloid complex, including the basolateral nucleus (BLA), contributes crucially to emotional and cognitive brain functions, and is a major target of research in both humans and rodents. However, delineating structural amygdala plasticity in both normal and disease-related contexts using neuroimaging has been hampered by the difficulty of unequivocally identifying the boundaries of the BLA. This challenge is a result of the poor contrast between BLA and the surrounding gray matter, including other amygdala nuclei. Here, we describe a novel diffusion tensor imaging (DTI) approach to enhance contrast, enabling the optimal identification of BLA in the rodent brain from magnetic resonance (MR) images. We employed this methodology together with a slice-shifting approach to accurately measure BLA volumes. We then validated the results by direct comparison to both histological and cellular-identity (parvalbumin)-based conventional techniques for defining BLA in the same brains used for MRI. We also confirmed BLA connectivity targets using DTI-based tractography. The novel approach enables the accurate and reliable delineation of BLA. Because this nucleus is involved in and changed by developmental, degenerative and adaptive processes, the instruments provided here should be highly useful to a broad range of neuroimaging studies. Finally, the principles used here are readily applicable to numerous brain regions and across species.