Molecular analysis in cytological samples obtained by endobronchial or oesophageal ultrasound guided needle aspiration in non-small cell lung cancer.

INTRODUCTION: Cytological samples obtained by endobronchial ultrasound (EBUS) are capital for diagnosis, staging and molecular profile in non-small cell lung carcinoma (NSCLC). OBJECTIVE: To assess the success rate of complete, partial and individual of molecular analysis in samples obtained by EBUS-guided transbronchial needle aspiration (TBNA) and/or by oesophageal ultrasound-guided fine needle aspiration with an echobronchoscope (EUS-B-FNA) in patients with NSCLC. METHODS: Prospective study including 90 patients with non-squamous NSCLC, or non-smoking squamous. Cytological samples were classified into two groups. Group 1: PEN membrane slide and/or cell blocks for the determination of mutations of EGFR, KRAS, ERBB2 and BRAF. Group 2: silane coated slides or cell blocks for rearrangements of ALK, ROS1 and MET amplification. RESULTS: The success rate was 78.6% for 4 molecular alterations (EGFR, KRAS, ALK and ROS1), and 44% for 7 determinations. The individual success rate for EGFR was 97%, KRAS 96.3%, ALK 85%, ROS1 82.3%, ERBB2 71.4%, BRAF 67.7% and MET 81.1%. There were no significant differences (p=0.489) in the number of molecular analyses (1-3 vs. 4) in group 1, depending on the types of samples (cell block vs. PEN membrane slide vs. cell block and PEN membrane slide). CONCLUSIONS: In patients with NSCLC, the cytological material obtained by ultrasound-guided needle aspiration is sufficient for individual and partial molecular analysis in the vast majority of cases. Membrane slides such as cell blocks are valid samples for molecular analysis.

SEOM clinical guidelines for the treatment of small-cell lung cancer (SCLC) (2019).

Small-cell lung cancer (SCLC) accounts for 15% of lung cancers. Only one-third of patients are diagnosed at limited stage. The median survival remains to be around 15-20 months without significative changes in the strategies of treatment for many years. In stage I and IIA, the standard treatment is the surgery followed by adjuvant therapy with platinum-etoposide. In stage IIB-IIIC, the recommended treatment is early concurrent chemotherapy with platinum-etoposide plus thoracic radiotherapy followed by prophylactic cranial irradiation in patients without progression. However, in the extensive stage, significant advances have been observed adding immunotherapy to platinum-etoposide chemotherapy to obtain a significant increase in overall survival, constituting the new recommended standard of care. In the second-line treatment, topotecan remains as the standard treatment. Reinduction with platinum-etoposide is the recommended regimen in patients with sensitive relapse (≥ 3 months) and new drugs such as lurbinectedin and immunotherapy are new treatment options. New biomarkers and new clinical trials designed according to the new classification of SCLC subtypes defined by distinct gene expression profiles are necessary.

Scaphoid Waist Nonunion in an 8-Year-Old: A Rare Occurrence.

CASE: Historically, the most common pattern of pediatric scaphoid injury described is at the distal pole, which has a high rate of success with nonoperative management. Injury patterns have evolved as children are more commonly presenting with adult-type fracture patterns. We present the case of a scaphoid waist fracture in an 8-year-old male that resulted in nonunion and required surgical fixation. CONCLUSION: This case highlights the trend of adult pattern scaphoid fractures in the pediatric population and the utility of magnetic resonance imaging in patients who do not have complete carpal bone ossification at the time of initial radiographic evaluation.

Effect of late preterm birth on lung clearance index and respiratory physiology in school-age children.

BACKGROUND: We hypothesized that former late preterm (LP) children have abnormal pulmonary physiology parameters, including uneven ventilation distribution, due to premature disruption of normal lung development. METHODS: A cross-sectional study evaluating former LP children at the age of 6 to 12 years as compared to term controls. Demographics and child's and family history of asthma/atopy/smoking were recorded. The outcome parameters were spirometry, multiple breath washout (MBW) measurement by lung clearance index (LCI), 6-minute walk test (6MWT), symptoms related to asthma and allergy, and Godin Leisure-Time Exercise Questionnaire. RESULTS: Twenty-nine former LP were compared to 30 term-control children (mean age, 8.2 ± 1.7 and 8.8 ± 1.8 years, respectively). LP had reduced forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) compared to term controls (FEV1 1.59 ± 0.48 vs 1.80 ± 0.39 L, P = 0.005 and FVC 1.73 ± 0.45 vs 1.99 ± 0.49 L, P = 0.009). There were no differences between the two groups regarding FEV1/FVC, forced expiratory flow between 25 and 75 (FEF25-75), LCI (7.10 ± 0.79 vs 6.96 ± 0.75, P = 0.50), 6MW distance, and weekly leisure-activity score. Former LP children had more episodes of wheezing and greater use of asthma medication. CONCLUSIONS: This pilot study suggests that LP have lower pulmonary function tests (PFTs) but not ventilation inhomogeneity measured by LCI or functional disturbance. It is unclear if the differences in PFTs are due to late prematurity by itself or are the consequence of maternal and neonatal factors associated with LP. Further larger studies are required to assess the long-term respiratory consequences of LP birth.

miRNA-197 and miRNA-184 are associated with brain metastasis in EGFR-mutant lung cancers

Introduction. The prognostic value of EGFR mutation in lung cancer patients with brain metastases is uncertain and therapeutic efficacy with EGFR TKI is limited. Looking for biomarkers closely related with early tumor changes and brain metastases in non-small cell lung cancer is warranted. MicroRNAs (miRNAs) are frequently deregulated in lung cancer. The objective of this study was to investigate whether some miRNAs are related with brain metastasis risk in EGFR-mutant non-small cell lung cancer patients. Materials and methods. miRNA quantification was retrospectively performed in formalin-fixed, extracranial paraffin-embedded adenocarcinoma tumor tissue available from 17 human samples of advanced non-small cell lung cancer patients. Samples were classified as brain metastasis group (5 EGFR-mutant patients with initial BM, EGFRm-BM+; and 6 EGFR wild-type patients with initial BM) and the control group (6 EGFR-mutant NSCLC patients without BM). The RNA obtained was preamplified and retro-transcribed, and the miRNA was quantified with the TaqMan OpenArray Human MiRNA Panel in the QuantStudio™ 12 K Flex Real-Time PCR system. Results. miRNA-197 and miRNA-184 showed a significant higher expression in EGFRm-BM+ group than in the control group (p = 0.017 and p = 0.01, for miRNA-197 and miRNA-184, respectively), with a trend toward overexpression in BM group compared with the control group (p = 0.08 and p = 0.065, for miRNA-197 and miRNA-184, respectively), without differences in expression in BM group according to EGFR mutational status (EGFR wild type vs. EGFR-mutant: p = 0.175 and p = 0.117, for miRNA-197, miRNA-184 respectively). Conclusions. miRNA-197 and miRNA-184 are overexpressed in EGFR-mutant patients with BM and they might be a new biomarker for stratifying the risk of BM in this subpopulation (AU)

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IL-36α expression is elevated in ulcerative colitis and promotes colonic inflammation.

A role for the IL-36 family of cytokines has been identified in the pathogenesis of psoriasis. Although significant mechanistic overlap can exist between psoriasis and inflammatory bowel disease (IBD), to date there have been no reports investigating the IL-36 family in gastrointestinal inflammation. Here we demonstrate that expression levels of IL-36α are specifically elevated in the colonic mucosa of ulcerative colitis patients. This elevated expression is mirrored in the inflamed colonic mucosa of mice, wherein IL-36 receptor deficiency confirmed this pathway as a mediator of mucosal inflammation. Il36r-/- mice exhibited reduced disease severity in an acute DSS-induced model of colitis in association with decreased innate inflammatory cell infiltration to the colon lamina propria. Consistent with these data, infection with the enteropathogenic bacteria Citrobacter rodentium, resulted in reduced innate inflammatory cell recruitment and increased bacterial colonization in the colons of il36r-/- mice. Il36r-/- mice also exhibited altered T helper cell responses in this model, with enhanced Th17 and reduced Th1 responses, demonstrating that IL-36R signaling also regulates intestinal mucosal T-cell responses. These data identify a novel role for IL-36 signaling in colonic inflammation and indicate that the IL-36R pathway may represent a novel target for therapeutic intervention in IBD.

miRNA-197 and miRNA-184 are associated with brain metastasis in EGFR-mutant lung cancers.

INTRODUCTION: The prognostic value of EGFR mutation in lung cancer patients with brain metastases is uncertain and therapeutic efficacy with EGFR TKI is limited. Looking for biomarkers closely related with early tumor changes and brain metastases in non-small cell lung cancer is warranted. MicroRNAs (miRNAs) are frequently deregulated in lung cancer. The objective of this study was to investigate whether some miRNAs are related with brain metastasis risk in EGFR-mutant non-small cell lung cancer patients. MATERIALS AND METHODS: miRNA quantification was retrospectively performed in formalin-fixed, extracranial paraffin-embedded adenocarcinoma tumor tissue available from 17 human samples of advanced non-small cell lung cancer patients. Samples were classified as brain metastasis group (5 EGFR-mutant patients with initial BM, EGFRm-BM+; and 6 EGFR wild-type patients with initial BM) and the control group (6 EGFR-mutant NSCLC patients without BM). The RNA obtained was preamplified and retro-transcribed, and the miRNA was quantified with the TaqMan OpenArray Human MiRNA Panel in the QuantStudio™ 12 K Flex Real-Time PCR system. RESULTS: miRNA-197 and miRNA-184 showed a significant higher expression in EGFRm-BM+ group than in the control group (p = 0.017 and p = 0.01, for miRNA-197 and miRNA-184, respectively), with a trend toward overexpression in BM group compared with the control group (p = 0.08 and p = 0.065, for miRNA-197 and miRNA-184, respectively), without differences in expression in BM group according to EGFR mutational status (EGFR wild type vs. EGFR-mutant: p = 0.175 and p = 0.117, for miRNA-197, miRNA-184 respectively). CONCLUSIONS: miRNA-197 and miRNA-184 are overexpressed in EGFR-mutant patients with BM and they might be a new biomarker for stratifying the risk of BM in this subpopulation.

Electrical Resistivity Imaging of Seawater Intrusion into the Monterey Bay Aquifer System.

We use electrical resistivity tomography to obtain a 6.8-km electrical resistivity image to a depth of approximately 150 m.b.s.l. along the coast of Monterey Bay. The resulting image is used to determine the subsurface distribution of saltwater- and freshwater-saturated sediments and the geologic controls on fluid distributions in the region. Data acquisition took place over two field seasons in 2011 and 2012. To maximize our ability to image both vertical and horizontal variations in the subsurface, a combination of dipole-dipole, Wenner, Wenner-gamma, and gradient measurements were made, resulting in a large final dataset of approximately 139,000 data points. The resulting resistivity section extends to a depth of 150 m.b.s.l., and is used, in conjunction with the gamma logs from four coastal monitoring wells to identify four dominant lithologic units. From these data, we are able to infer the existence of a contiguous clay layer in the southern portion of our transect, which prevents downward migration of the saltwater observed in the upper 25 m of the subsurface to the underlying freshwater aquifer. The saltwater and brackish water in the northern portion of the transect introduce the potential for seawater intrusion into the hydraulically connected freshwater aquifer to the south, not just from the ocean, but also laterally from north to south.

Search for common targets of lithium and valproic acid identifies novel epigenetic effects of lithium on the rat leptin receptor gene.

Epigenetics may have an important role in mood stabilizer action. Valproic acid (VPA) is a histone deacetylase inhibitor, and lithium (Li) may have downstream epigenetic actions. To identify genes commonly affected by both mood stabilizers and to assess potential epigenetic mechanisms that may be involved in their mechanism of action, we administered Li (N = 12), VPA (N = 12), and normal chow (N = 12) to Brown Norway rats for 30 days. Genomic DNA and mRNA were extracted from the hippocampus. We used the mRNA to perform gene expression analysis on Affymetrix microarray chips, and for genes commonly regulated by both Li and VPA, we validated expression levels using quantitative real-time PCR. To identify potential mechanisms underlying expression changes, genomic DNA was bisulfite treated for pyrosequencing of key CpG island 'shores' and promoter regions, and chromatin was prepared from both hippocampal tissue and a hippocampal-derived cell line to assess modifications of histones. For most genes, we found little evidence of DNA methylation changes in response to the medications. However, we detected histone H3 methylation and acetylation in the leptin receptor gene, Lepr, following treatment with both drugs. VPA-mediated effects on histones are well established, whereas the Li effects constitute a novel mechanism of transcriptional derepression for this drug. These data support several shared transcriptional targets of Li and VPA, and provide evidence suggesting leptin signaling as an epigenetic target of two mood stabilizers. Additional work could help clarify whether leptin signaling in the brain has a role in the therapeutic action of Li and VPA in bipolar disorder.

Effects of meal composition on postprandial incretin, glucose and insulin responses after surgical and medical weight loss.

BACKGROUND: Meal tolerance tests are frequently used to study dynamic incretin and insulin responses in the postprandial state; however, the optimal meal that is best tolerated and suited for hormonal response following surgical and medical weight loss has yet to be determined. OBJECTIVE: To evaluate the tolerability and effectiveness of different test meals in inducing detectable changes in markers of glucose metabolism in individuals who have undergone a weight loss intervention. METHODS: Six individuals who underwent surgical or medical weight loss (two Roux-en-Y gastric bypass, two sleeve gastrectomy and two medical weight loss) each completed three meal tolerance tests using liquid-mixed, solid-mixed and high-fat test meals. The tolerability of each test meal, as determined by the total amount consumed and palatability, as well as fasting and meal-stimulated glucagon-like peptide, glucose-dependent insulinotropic polypeptide, insulin and glucose were measured. RESULTS: Among the six individuals, the liquid-mixed meal was better and more uniformly tolerated with a median meal completion rate of 99%. Among the four bariatric surgical patients, liquid-mixed meal stimulated on average a higher glucagon-like peptide (percent difference: 83.7, 89), insulin secretion (percent difference: 155.1, 158.7) and glucose-dependent insulinotropic polypeptide (percent difference: 113.5, 34.3) compared with solid-mixed and high-fat meals. CONCLUSIONS: The liquid-mixed meal was better tolerated with higher incretin and insulin response compared with the high-fat and solid-mixed meals and is best suited for the evaluation of stimulated glucose homeostasis.

Oesophageal manometry: 10-year audit from a specialist centre, and early experience with high-resolution manometry.

BACKGROUND: Manometry is the gold standard investigation of innate or acquired motility disorders in the oesophagus. New technology in the form of high-resolution manometry (HRM) may supplant traditional water-perfused manometry and enhance standardisation of manometric interpretation and reporting. This study reports on a 10-year experience of 5,184 consecutive patients using the traditional methods, and an early experience with HRM. RESULTS: Of 5,184 patients assessed, 4,509 (87%) had both pH and manometry and 675 (13%) had manometry only. 3,523 (78%) of the pH /manometry group had normal motility, 635 (14%) showed ineffective motility (IM), 213 (5%) a non-specific motility disturbance (NSMD), 42 (0.9%) achalasia, 58 (1.3%) nutcracker oesophagus, 22 (0.5%) hypertensive LOS (HLOS), 8 (0.2%) diffuse oesophageal spasm (DOS) and 8 (0.2 %) had scleroderma. For those referred solely for manometry only, 324 (48%) had normal motility, 72 (11%) IM, 51 (8%) NSMD, 175 (26%) achalasia, 16 (2%) nutcracker oesophagus, 32 (5%) HLOS, 1 (0.1%) DOS and 4 (0.6%) had scleroderma. 92 patients to date have been studied with HRM, with enhanced definition of lower oesophageal sphincter (LOS) function. CONCLUSION: For patients referred for reflux related symptoms, motility disorders are present in 22% of the cases. Conversely, of the patients referred for dysphagia, motility disturbances are detected in 52% of the cases sent for manometry. Our initial experience shows that HRM technology is adding a valuable dimension and clearer understanding of motility patterns in the dysphagic patient.

Two biomarker-directed randomized trials in European and Chinese patients with nonsmall-cell lung cancer: the BRCA1-RAP80 Expression Customization (BREC) studies.

BACKGROUND: In a Spanish Lung Cancer Group (SLCG) phase II trial, the combination of BRCA1 and receptor-associated protein 80 (RAP80) expression was significantly associated with outcome in Caucasian patients with nonsmall-cell lung cancer (NSCLC). The SLCG therefore undertook an industry-independent collaborative randomized phase III trial comparing nonselected cisplatin-based chemotherapy with therapy customized according to BRCA1/RAP80 expression. An analogous randomized phase II trial was carried out in China under the auspices of the SLCG to evaluate the effect of BRCA1/RAP80 expression in Asian patients. PATIENTS AND METHODS: Eligibility criteria included stage IIIB-IV NSCLC and sufficient tumor specimen for molecular analysis. Randomization to the control or experimental arm was 1 : 1 in the SLCG trial and 1 : 3 in the Chinese trial. In both trials, patients in the control arm received docetaxel/cisplatin; in the experimental arm, patients with low RAP80 expression received gemcitabine/cisplatin, those with intermediate/high RAP80 expression and low/intermediate BRCA1 expression received docetaxel/cisplatin, and those with intermediate/high RAP80 expression and high BRCA1 expression received docetaxel alone. The primary end point was progression-free survival (PFS). RESULTS: Two hundred and seventy-nine patients in the SLCG trial and 124 in the Chinese trial were assessable for PFS. PFS in the control and experimental arms in the SLCG trial was 5.49 and 4.38 months, respectively [log rank P = 0.07; hazard ratio (HR) 1.28; P = 0.03]. In the Chinese trial, PFS was 4.74 and 3.78 months, respectively (log rank P = 0.82; HR 0.95; P = 0.82). CONCLUSION: Accrual was prematurely closed on the SLCG trial due to the absence of clinical benefit in the experimental over the control arm. However, the BREC studies provide proof of concept that an international, nonindustry, biomarker-directed trial is feasible. Thanks to the groundwork laid by these studies, we expect that ongoing further research on alternative biomarkers to elucidate DNA repair mechanisms will help define novel therapeutic approaches. TRIAL REGISTRATION: NCT00617656/GECP-BREC and ChiCTR-TRC-12001860/BREC-CHINA.

Beyond EGFR TKI in EGFR-mutant non-small cell lung cancer patients: main challenges still to be overcome.

First line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) is the standard treatment in advanced EGFR-mutant Non Small Cell Lung Cancer (NSCLC) patients, with an improvement in response rate, progression free survival, and quality of life compared with upfront chemotherapy. However, in the real world, EGFR mutation results often return positive once chemotherapy has been started. Different clinical strategies have been tested in this situation: reserve the EGFR TKI until tumor become resistant beyond chemotherapy, stop chemotherapy and switch to EGFR TKI, introduce the EGFR TKI as a maintenance treatment, or combined strategies such as intercalated or concurrent EGFR TKI plus chemotherapy. In this review, we aim to summarize the clinical evidence of first line treatment strategy with EGFR TKI and discuss the potential options in the sequence of treatment in EGFR-mutant patients.

Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors in EGFR-mutant non-small cell lung cancer: a new era begins.

The discovery of mutated oncogenes has opened up a new era for the development of more effective treatments for non-small cell lung cancer patients (NSCLC) harbouring EGFR mutations. However, patients with EGFR-activating mutation ultimately develop acquired resistance (AR). Several studies have identified some of the mechanisms involved in the development of AR to EGFR tyrosine kinase inhibitors (TKI) that can be potential therapeutic strategies, although in up to 30% of cases, the underlying mechanism of AR are still unexplained. In this review we aim to summarize the main mechanisms of AR to EGFR TKI and some clinical strategies that can be used in the daily clinical practice to overcome this resistance and try to prolong the outcomes in this subgroup of patients.

The otological manifestations associated with autistic spectrum disorders.

OBJECTIVES: To elucidate the otological manifestations found in this increasingly commonly diagnosed condition. This paper will discuss the diagnosis, aetiology, pathogenesis, management and the outcomes of treatment. STUDY DESIGN: Systematic literature review. MATERIALS AND METHODS: The following databases were searched for articles pertaining to the otological manifestations of autistic spectrum disorders: MEDLINE, EMBASE, CURRENT CONTENTS, PSYCHLIT, CINAHL and HEALTHSTAR. Articles from 1965 to June 2012 were extracted. Relevant articles from the literature were selected and reviewed by two independent authors. Each paper was assessed as to its level of evidence and validity. The relevant results are presented and discussed in order to present a practical approach to the management of these patients. RESULTS: Patients with ASD have an increased incidence of peripheral and central otological pathology. This pathology plays a key role in the behavioural, communication, and social aspects of the disease. ASD patients have a higher incidence of profound sensorineural hearing loss, middle ear infections, and abnormalities of the cochlear nerve and brainstem auditory pathways. There are cortical and brainstem neurodevelopmental abnormalities in the way auditory information is interpreted and processed in the ASD patient. CONCLUSIONS: The otolaryngologist plays a key role in the multidisciplinary management of individuals with ASD due to the high prevalence of otological pathology amongst these patients. Early diagnosis and expedient treatment focusing on normalisation of auditory input and development can maximise developmental outcomes.

Palatable food avoidance and acceptance learning with different stressors in female rats.

Stress activates the hypothalamus-pituitary-adrenal (HPA) axis leading to the release of glucocorticoids (GC). Increased activity of the HPA axis and GC exposure has been suggested to facilitate the development of obesity and metabolic syndrome. Nonetheless, different stressors can produce distinct effects on food intake and may support different directions of food learning e.g. avoidance or acceptance. This study examined whether interoceptive (LiCl and exendin-4) and restraint stress (RS) support similar or distinct food learning. Female rats were exposed to different stressors after their consumption of a palatable food (butter icing). After four palatable food-stress pairings, distinct intakes of the butter icing were observed in rats treated with different stressors. Rats that received butter icing followed by intraperitoneal injections of LiCl (42.3mg/kg) and exendin-4 (10µg/kg) completely avoided the palatable food with subsequent presentations. In contrast, rats experiencing RS paired with the palatable food increased their consumption of butter icing across trials and did so to a greater degree than rats receiving saline injections. These data indicate that interoceptive and psychosocial stressors support conditioned food avoidance and acceptance, respectively. Examination of c-Fos immunoreactivity revealed distinct neural activation by interoceptive and psychosocial stressors that could provide the neural basis underlying opposite direction of food acceptance learning.

Additive feeding inhibitory and aversive effects of naltrexone and exendin-4 combinations.

OBJECTIVE: One developing strategy for obesity treatment has been to use combinations of differently acting pharmacotherapies to improve weight loss with fewer adverse effects. The purpose of this study was to determine whether the combination of naltrexone (Nal), an opioid antagonist acting on the reward system, and exendin-4 (Ex-4), a glucagon-like peptide 1 agonist acting on satiety signaling, would produce larger reductions in food intake than either alone in rats. Because the anorectic potencies of both compounds have been associated with nausea and malaise, the influence of these drug combinations on the acquisition of a conditioned taste aversion (CTA) was also determined. METHODS: In Experiment 1, the acute anorectic effects of Nal (0.32-3.2 mg kg(-1); intraperitoneally (i.p.)) and Ex-4 (1-10 µg kg(-1); i.p.) were assessed alone or in combination. Combinational doses were further investigated by the repeated daily administration of 1 mg kg(-1) Nal+3.2 µg kg(-1) Ex-4 for 4 days. In Experiment 2, both compounds alone or in combination were used as unconditioned stimuli in a series of CTA tests. RESULTS: Nal and Ex-4, alone or in combination, suppressed food intake in a dose-dependent manner, and the interaction on food intake between Nal and Ex-4 was additive. In the CTA paradigm, Nal (1 mg kg(-1)) alone did not support acquisition, whereas a CTA was evident with doses of Ex-4 (1 or 3.2 µg kg(-1)). Combinations of Nal and Ex-4 also resulted in a more rapid and robust acquisition of a CTA. CONCLUSION: Given that the Nal and Ex-4 combination produces additive effects on not only food intake reduction but also food aversion learning, this specific drug combination does not have the benefit of minimizing the adverse effects associated with each individual drug. These data suggest that it is necessary to evaluate both the positive and adverse effects at early stages of combinational drug development.

The tyrosine phosphatase STEP constrains amygdala-dependent memory formation and neuroplasticity.

STriatal-Enriched protein tyrosine Phosphatase (STEP; PTPN5) is expressed in brain regions displaying adult neuroplasticity. STEP modulates neurotransmission by dephosphorylating regulatory tyrosine residues on its substrates. In this way, STEP inactivates extracellular-signal-regulated kinase 1/2 (ERK1/2), limiting the duration and spatial distribution of ERK signaling. Two additional substrates, the tyrosine kinase Fyn and the NR2B subunit of the N-methyl-d-aspartic acid receptor, link STEP to glutamate receptor internalization in the synapse. Thus, STEP may act through parallel pathways to oppose the development of experience-dependent synaptic plasticity. We examined the hypothesis that the absence of STEP facilitates amygdala-dependent behavioral and synaptic plasticity (i.e., fear conditioning and long-term potentiation) using STEP-deficient mice (STEP KO). These mice show no detectable expression of STEP in the brain along with increases in Tyr phosphorylation of STEP substrates. Here we demonstrate that STEP KO mice also display augmented fear conditioning as measured by an enhancement in conditioned suppression of instrumental response when a fear-associated conditioned stimulus was presented. Deletion of STEP also increases long-term potentiation and ERK phosphorylation in the lateral amygdala. The current experiments demonstrate that deletion of STEP can enhance experience-induced neuroplasticity and memory formation and identifies STEP as a target for pharmacological treatment aimed at improving the formation of long-term memories.