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Nervous system functions in all animals rely upon synaptic connectivity that is established during early development. Whereas cell- cell signaling plays a critical role in establishing synapse specificity, the involvement of extrinsic growth factors cannot, however, be undermined. We have previously demonstrated that trophic factors are required for excitatory but not inhibitory synapse formation between Lymnaea neurons. Moreover, in the absence of trophic factors, neurons from a number of species establish inappropriate inhibitory synapses, which can, however, be corrected by the addition of trophic factors. The precise site of trophic factor actions (presynaptic versus postsynaptic) and the underlying mechanisms remain, however, undefined. Here, we provide the first direct evidence that the trophic factor-mediated excitatory synapse formation involves activity-induced calcium (Ca2+) oscillations in the postsynaptic left pedal dorsal 1 (LPeD1) but not the presynaptic visceral dorsal 4 (VD4, cholinergic) neuron. These oscillations involved Ca2+ influx through voltagegated Ca2+ channels and required receptor tyrosine kinase activity which was essential for the expression of excitatory, nicotinic acetylcholine receptors in the postsynaptic cell during synapse formation. We also demonstrate that selectively blocking the electrical activity presynaptically did not perturb trophic factor-induced synapse formation between the paired cells, whereas hyperpolarizing the postsynaptic cell prevented appropriate synaptogenesis between VD4 and LPeD1 cells. Together, our data underscore the importance of extrinsic trophic factors in regulating the electrical activity of the postsynaptic but not the presynaptic cell and that the resulting Ca2+ oscillations are essential for the expression of postsynaptic receptors during specific synapse formation. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the relationship between choriocapillaris (CC), flow deficits (FD), and structural optical coherence tomography (OCT) biomarkers, and the progression of intermediate age-related macular degeneration (iAMD) to complete retinal pigment epithelial and outer retinal atrophy (cRORA) or macular neovascularization (MNV). Methods: Consecutive patients with iAMD were sequentially reviewed to define three equal sized groups: progressed to MNV, progressed to cRORA, or remained stable over 12 months of follow-up. Odds ratios for progression to cRORA and MNV were estimated by logistic regression for intraretinal hyperreflective foci (IHRF), hyporeflective drusen cores (hDC), subretinal drusenoid deposits (SDDs), high central drusen volume, fellow eye with late AMD, and peripheral and central CC FD. Results: Thirty iAMD eyes from 30 patients were enrolled into each group. The CC FD was greater in the peripheral sectors of the macula of eyes which progressed to cRORA compared to the other two groups (P < 0.0001). The central CC FD was also significantly impaired in eyes that progressed to cRORA or MNV compared to eyes that did not progress (P = 0.001 and P = 0.02, respectively). CC FD in the peripheral macula was significantly and independently associated with the development of cRORA, while CC FD in the center was significantly and independently associated with the development of MNV. Conclusions: While the CC is diffusely impaired throughout the macula in iAMD eyes that progress to cRORA, it is relatively spared in the more peripheral macula among eyes which progress to MNV. These differential findings may have implications for the pathophysiology of the different late-stage manifestations of AMD. [ABSTRACT FROM AUTHOR]

Objective: To determine if targeted and modulated radiofrequency ablation (RFA) of the urinary bladder using our novel ablation device (Denerblate) reduces bladder nerve density, potentially leading to a novel strategy for the management of overactive bladder.Methods: Fifteen pigs were divided into 4 groups: control (n = 3), 1-week (n = 4), 4-week (n = 4) and 12-week (n = 4) survival times. Denerblate was deployed on the trigone area of the bladder. Three 240-second cycles of modulated RFA were applied with 30 seconds between cycles. At the end of each survival term, urinary bladders were harvested for histopathologic evaluation. Nerve count and density were manually calculated.Results: All procedures were successfully completed, and all animals survived to the desired time points. Mean nerve density (nerves/mm2) was highest in the control and 1-week survival group compared to the 4-week and 12-week groups, both of which demonstrated significant diminishment. Nerve density in the bladder neck at control, 1 week, 4 weeks, and 12 weeks were 1.8, 1.35, 0.87, and 0.12, respectively (P <.001). Nerve density in the bladder trigone area at control, 1 week, 4 weeks, and 12 weeks were 1.5, 0.98, 0.65, and 0.112, respectively (P <.001). Epithelial heat injury was observed in 14.3% at 1 week, 10.7% at 4 weeks, but completely resolved by 12 weeks.Conclusion: In the porcine model, modulated RFA delivered by our novel device reduced nerve density in the bladder neck and trigone by 88.6% and 88.9% at 12 weeks without evidence of lasting epithelial injury. [ABSTRACT FROM AUTHOR]

Objectives: Checkpoint inhibitors are approved for the treatment of urothelial bladder cancer. However, there have been no reports on the prognostic value of programmed-death receptor ligand 1 (PD-L1) expression in squamous cell carcinoma (SCC) of the bladder. We assessed the relationship between PD-L1 expression, clinicopathological features, and oncologic outcomes in bladder SCC.Methods and Materials: Immunohistochemistry of PD-L1 was performed on 151 radical cystectomy specimens with pure SCC treated in Mansoura, Egypt from 1997 to 2004.Results: Median patient age was 52 years (range: 36-74 years) and median length of follow up was 63 months (range: 1-100 months). Schistosomiasis was present in 81% of the specimens and 93% had muscle-invasive disease on pathologic staging. PD-L1 expression was negative in 50 (33%) of the specimens. Negative PD-L1 expression was associated with higher pathologic tumor stage (P = 0.04), higher grade lesions (P = 0.01), and the presence of lymphovascular invasion (P < 0.01). Kaplan-Meier analyses showed that negative PD-L1 expression is associated with worse recurrence-free (P = 0.01) and worse cancer-specific survival (P = 0.01). Multivariable Cox regression analyses showed negative PD-L1 expression was an independent predictor of disease recurrence (hazards ratio 2.05, 95% confidence interval 1.06-3.96, P = 0.03) and cancer-specific mortality (hazards ratio 2.89, 95% confidence interval 1.22-6.82, P = 0.02).Conclusions: Negative PD-L1 expression is associated with higher pathologic tumor stage, higher grade lesions, presence of lymphovascular invasion, and worse oncologic outcomes after radical cystectomy for SCC. These findings support the need for the inclusion of patients with bladder SCC into immunotherapy clinical trials. [ABSTRACT FROM AUTHOR]

Objective: To compare the performance of 3 contemporary ureteroscopic biopsy devices for the histopathologic diagnosis of upper tract urothelial carcinoma (UTUC).Methods: We retrospectively reviewed 145 patients who underwent 182 urothelial biopsies using 2.4F backloaded cup biopsy forceps, a nitinol basket, or 3F standard cup biopsy forceps at 3 tertiary academic centers between 2011 and 2016. Experienced genitourinary pathologists provided an assessment of each specimen without knowledge of the device used for biopsy. For patients who underwent nephroureterectomy without neoadjuvant chemotherapy within 3 months of biopsy-proven UTUC diagnosis, the biopsy grade was compared with both the grade and stage of the surgical specimen.Results: Biopsy utilization varied among the 3 institutions (P <.0001). Significant variabilities in specimen size (P = .001), the presence of intact urothelium (P = .008), and crush artifact (P = .028) were found among the biopsy devices. The quality of specimens from backloaded cup forceps was rated similarly to the nitinol basket (P >.05) and was favored over standard cup forceps specimens. Grade concordance was not affected by specimen size (P >.05), morphology (P >.1), or location (P >.5). No difference existed among the devices in the rate of acquiring a grade concordant biopsy; however, the backloaded cup forceps provided concordant biopsies that could be distinguished as low- and high-grade (P = .02).Conclusion: The backloaded cup forceps and nitinol basket obtained a higher quality urothelial specimen compared with standard cup forceps. Ureteroscopic biopsy device selection did not significantly impact the accuracy of the histologic diagnosis of UTUC. [ABSTRACT FROM AUTHOR]

Like many carcinomas, urothelial carcinoma (UroCa) is associated with chronic injury. A better understanding of this association could inform improved strategies for preventing and treating this disease. We investigated the expression, regulation, and function of the transcriptional regulator SRY-related high-mobility group box 9 (Sox9) in urothelial development, injury repair, and cancer. In mouse bladders, Sox9 levels were high during periods of prenatal urothelial development and diminished with maturation after birth. In adult urothelial cells, Sox9 was quiescent but was rapidly induced by a variety of injuries, including exposure to the carcinogen cyclophosphamide, culture with hydrogen peroxide, and osmotic stress. Activation of extracellular signal-regulated kinases 1/2 (ERK1/2) was required for Sox9 induction in urothelial injury and resulted from activation of the epidermal growth factor receptor (Egfr) by several Egfr ligands that were dramatically induced by injury. In UroCa cell lines, SOX9 expression was constitutively upregulated and could be suppressed by EGFR or ERK1/2 blockade. Gene knockdown showed a role for SOX9 in cell migration and invasion. Accordingly, SOX9 protein levels were preferentially induced in invasive human UroCa tissue samples (n = 84) compared with noninvasive cancers (n = 56) or benign adjacent urothelium (n = 49). These results identify a novel, potentially oncogenic signaling axis linking urothelial injury to UroCa. Inhibiting this axis is feasible through a variety of pharmacologic approaches and may have clinical utility. [ABSTRACT FROM AUTHOR]

Purpose: The International Ki67 Working Group (IKWG) has developed training for immunohistochemistry (IHC) scoring reproducibility and recommends cut points of ≤ 5% and ≥ 30% for prognosis in ER+, HER2-, stage I/II breast cancer. We examined scoring reproducibility following IKWG training and evaluated these cut points for selecting patients for further testing with the 21-gene Recurrence Score (RS) assay., Methods: We included 307 women aged 50+ years with node-negative, ER+PR+HER2- breast cancer and with available RS results. Slides from the diagnostic biopsy were stained for Ki67 and scored using digital image analysis (IA). Two IHC pathologists underwent IKWG training and visually scored slides, blinded to each other and IA readings. Interobserver reproducibility was examined using intraclass correlation (ICC) and Kappa statistics., Results: Depending on reader, 8.8-16.0% of our cohort had Ki67 ≤ 5% and 11.4-22.5% had scores ≥ 30%. The ICC for Ki67 scores by the two pathologists was 0.82 (95% CI 0.78-0.85); it was 0.79 (95% CI 0.74-0.83) for pathologist 1 and IA and 0.76 (95% CI 0.71-0.80) for pathologist 2 and IA. For Ki67 scores ≤ 5%, the percentages with RS < 26 were 92.6%, 91.8%, and 90.9% for pathologist 1, pathologist 2, and IA, respectively. For Ki67 scores ≥ 30%, the percentages with RS ≥ 26 were 41.5%, 51.4%, and 27.5%, respectively., Conclusion: The IKWG's Ki67 training resulted in moderate to strong reproducibility across readers but cut points had only moderate overlap with RS cut points, especially for Ki67 ≥ 30% and RS ≥ 26; thus, their clinical utility for a 21-gene assay testing pathway remains unclear., (© 2023. The Author(s).)

Mitotic rate is an important prognostic predictor in invasive breast carcinoma. Current guidelines recommend counting mitoses from 10 contiguous high power fields (HPFs) in the core biopsy. We propose a method to score mitotic activity in 1 HPF at the most mitotically active area of the tumour edge, or the interface between invasive tumour and benign breast tissue. We propose a score of 1, 2, or 3, corresponding to ≤1, 2, or ≥3 mitoses in 1 HPF, respectively. A total of 141 breast core biopsies with corresponding surgical excisions were blindly examined. We counted the number of mitotic figures in 1 HPF and in 10 contiguous HPFs in the core biopsy and compared with the mitotic count from 10 contiguous HPFs in the excision which is considered the gold standard. Concordance rates and interobserver agreement rates were calculated. The concordance rate was 82.3%, 78.7% and 82.3% between 1 HPF versus 10 HPFs in the core biopsy, 1 HPF in the core biopsy versus 10 HPFs in the excision and 10 HPFs in the core biopsy vs 10 HPFs in the excision, respectively. In the core biopsy, all three investigators agreed in 73.8% and 83.7% of the cases using the 1 HPF method and the 10 HPFs method, respectively; in the excision specimen, agreement was reached in 82.3% of the cases. The 1 HPF method showed similar concordance rate and interobserver agreement compared to the conventional method in the prediction of the mitotic score in the excision in all score groups. When stratified by mitotic score, the 1 HPF method predicted superior correlation with excision in the score 1 group than the 10 HPFs method, but not in the score 2 or 3 groups. From these findings we conclude that the proposed 1 HPF method can be used in clinical practice to grade invasive breast carcinomas in core biopsies, with the possibility of being utilised in small biopsies with less than 10 HPFs of invasive carcinoma., (Copyright © 2021 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.)

Purpose: To investigate the visual and anatomical outcomes associated with treat-and-extend (TAE) regimen of intravitreal (IVT) aflibercept in eyes with treatment naïve neovascular age-related macular degeneration (nvAMD)., Methods: A retrospective chart review of eyes that underwent IVT aflibercept injections for nvAMD between May 2014 and March 2018 was performed. The primary outcome was the change in best corrected visual acuity (BCVA) at 12 months. Secondary outcomes included the change in central retinal thickness (CRT), subretinal fluid (SRF) and intraretinal fluid (IRF)., Results: Data from 213 eyes of 213 patients (138 female, 65%) met the inclusion criteria. The mean (SD) age of the patients was 80.4 (±  9.2) years. The mean baseline BCVA (0.92  ±  0.50 logMAR, improved by 0.20 (±  0.40) logMAR units at 12 months (p  <  0.001). Seventy-two (34%) eyes gained  ≥  0.3 logMAR and 47 (22%) eyes achieved BCVA  ≤  0.3 logMAR at 12 months. Baseline BCVA, patient age, and the number of aflibercept injections received were predictors of the change in BCVA at 12 months. Mean CRT improved from 347 (±  117) µm at baseline to 246 (±  55) µm at 12 months (p  <  0.001). The percentage of eyes with SRF and IRF on SD-OCT declined from 63 to 21% and from 60 to 26% at 12 months, respectively., Conclusion: A TAE regimen of IVT aflibercept in treatment naïve nvAMD is associated with good visual and anatomical outcomes in routine clinical practice. Resolution of exudation occurred in about half of nvAMD cases at 12 months. Individualized administration of IVT aflibercept may reduce injection burden., (© 2021. The Author(s).)

The terms composite and collision tumors have been used interchangeably throughout radiological literature. Both composite and collision tumors involve two morphologically and immunohistochemically distinct neoplasms coexisting within a single organ. However, collision tumors lack the histological cellular intermingling seen in composite tumors. Composite tumors often arise from a common driver mutation that induces a divergent histology from a common neoplastic source while collision tumors may arise from coincidental neoplastic change. The purpose of this review is to provide an overview of abdominal composite and collision tumors by discussing hallmark radiographic and pathological presentations of rare hepatic, renal, and adrenal case studies. A better understanding of the presentation of each lesion is imperative for proper recognition, diagnosis, and management of these unique tumor presentations.

Unlabelled: Neuroendocrine tumors comprise a heterogeneous group of malignancies with a broad spectrum of clinical behavior. Poorly differentiated tumors follow an aggressive course with limited treatment options, and new approaches are needed. Oncogenic BRAF V600E (BRAF(V600E)) substitutions are observed primarily in melanoma, colon cancer, and non-small cell lung cancer, but have been identified in multiple tumor types. Here, we describe the first reported recurrent BRAF(V600E) mutations in advanced high-grade colorectal neuroendocrine tumors and identify a BRAF alteration frequency of 9% in 108 cases. Among these BRAF alterations, 80% were BRAF(V600E) Dramatic response to BRAF-MEK combination therapy occurred in two cases of metastatic high-grade rectal neuroendocrine carcinoma refractory to standard therapy. Urinary BRAF(V600E) circulating tumor DNA monitoring paralleled disease response. Our series represents the largest study of genomic profiling in colorectal neuroendocrine tumors and provides strong evidence that BRAF(V600E) is an oncogenic driver responsive to BRAF-MEK combination therapy in this molecular subset., Significance: BRAF(V600E) is an established oncogenic driver, but significant disparities in response exist among tumor types. Two patients with treatment-refractory high-grade colorectal neuroendocrine tumors harboring BRAF(V600E) exhibited rapid and durable response to combined BRAF-MEK inhibition, providing the first clinical evidence of efficacy in this aggressive tumor type. Cancer Discov; 6(6); 594-600. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 561., Competing Interests: KG, AS, JR, VAM, PJS, and SMA are stockholders and employees of Foundation Medicine. MGE is a stockholder and employee of Trovagene. The remaining authors have no potential conflicts of interest to disclose., (©2016 American Association for Cancer Research.)

Obesity and inactivity have been associated with advanced-stage prostate cancer, and poor prostate cancer outcomes, though the underlying mechanism(s) is unknown. To determine whether telomere shortening, which has been associated with lethal prostate cancer, may be a potential underlying mechanism, we prospectively evaluated the association between measures of adiposity, physical activity, and telomere length in 596 participants in the Health Professionals Follow-up Study, who were surgically treated for prostate cancer. Using tissue microarrays, we measured telomere length in cancer and benign cells using a telomere-specific FISH assay. Adiposity and activity were assessed via questionnaire within 2 years of diagnosis. Adjusting for age, pathologic stage, and grade, the median and SD of the per cell telomere signals were determined for each man for stromal cells and cancer cells by adiposity and activity categories. Overweight/obese men (54%) were similar to normal weight men on most factors, but had higher Gleason sum and lower activity levels. Overweight/obese men had 7.4% shorter telomeres in stromal cells than normal weight men (P = 0.06). The least active men had shorter telomeres in stromal cells than more active men (Ptrend = 0.002). Men who were overweight/obese and the least active had the shortest telomeres in stromal cells (20.7% shorter; P = 0.0005) compared with normal weight men who were the most active. Cancer cell telomere length and telomere length variability did not differ by measures of adiposity or activity. Telomere shortening in prostate cells may be one mechanism through which lifestyle influences prostate cancer risk and outcomes., (©2015 American Association for Cancer Research.)

Objective: Best disease is a slowly progressive macular dystrophy that typically has an onset in early childhood. Multiple lines of evidence suggest that dietary docosahexaenoic acid (DHA) protects against the development of macular degeneration. Our trial tested the effect of an oral supplement of DHA on visual function in patients with Best disease., Design: Double-masked, randomized, placebo-controlled, crossover clinical trial., Participants: Eight patients with Best disease., Methods: Patients were given either an oral supplement of DHA (20 mg/kg daily) or placebo. Primary outcome measures were the multifocal electroretinogram (mfERG) and electro-oculogram (EOG). Plasma DHA was tracked along with visual acuity (Early Treatment Diabetic Retinopathy Study chart), VF-14 scores, and Humphrey visual fields., Results: All 8 patients had increased plasma DHA levels (2-3 fold) during periods of DHA supplementation compared with periods without supplementation. Differences in visual acuity, VF-14 scores, and EOG Arden ratios during periods with and without DHA supplementation were all statistically insignificant. A positive correlation was found between the plasma concentration of DHA and mfERG amplitudes, but amplitude changes during the treatment periods were not significant. A carryover effect of DHA supplementation was a confounding error., Conclusions: Our pilot trial of DHA supplementation in 8 patients with Best disease did not demonstrate an improvement in macular function. An expanded trial would be needed to examine the full effects of DHA supplementation on visual function in Best disease.

Purpose of Review: Age-related macular degeneration (AMD) was until recently viewed as a part of the normal aging process; however, we are increasingly aware that genetic factors play a much greater role than previously suspected. This review will provide an up-to-date snapshot of the genetics of AMD to help guide our thoughts about its causes and the risk for family members., Recent Findings: Epidemiological research and basic bench research have identified pathways of oxidative stress, lipid metabolism and inflammation as playing causative roles in the pathogenesis of AMD. Emerging research is focusing on the biology of the retinal pigment epithelium as secreting pro and anti-inflammatory mediators in the eye. Antivascular endothelial growth factor therapy has dramatically improved the prognosis for neovascular or wet AMD patients. Nutritional supplementation with antioxidants and omega-3 fatty acids has provided treatment options for patients with atrophic or dry AMD. We should expect that some of the response to therapy might be genetically determined., Summary: First-degree relatives of patients with AMD tend to have a higher risk of AMD. Recognizing an inherent genetic risk of AMD in these patients will improve their management and potentially help prevent blindness.

Most information available to date regarding the cellular and synaptic mechanisms of target cell selection and specific synapse formation has primarily come from in vitro cell culture studies. Whether fundamental mechanisms of synapse formation revealed through in vitro studies are similar to those occurring in vivo has not yet been determined. Taking advantage of the regenerative capabilities of adult molluscan neurons, we demonstrate that when transplanted into the host ganglia an identified neuron reestablishes its synaptic connections with appropriate targets in vivo. This synaptogenesis, however, was possible only if the targets were denervated from the host cell. Specifically, the giant dopamine neuron right pedal dorsal 1 (RPeD1) located in the pedal ganglia was isolated from a donor brain and transplanted into the visceral ganglia of the recipient brain. We discovered that within 2-4 days the transplanted RPeD1 exhibited extensive regeneration. However, simultaneous intracellular recordings failed to reveal synapses between the transplanted cell and its targets in the visceral ganglia, despite physical overlap between the neurites. To test whether the failure of a transplanted cell to innervate its target was due to the fact that the targets continued to receive input from the native RPeD1, the latter soma was surgically removed prior to the transplantation of RPeD1. Even after the removal of host soma, the transplanted RPeD1 failed to innervate the targets such as visceral dorsal 4 (VD4)-despite extensive regeneration by the transplanted cell. However, when RPeD1 axon was allowed to degenerate completely, the transplanted RPeD1 successfully innervated all of its targets and these synapses were similar to those seen between host RPeD1 and its targets. Taken together, our data demonstrate that the transplanted cells will innervate their potential targets only if the targets were denervated from the host cell. These data also lend support to the idea that, irrespective of their physical location in the brain, the displaced neurons are able to regenerate, recognize their targets, and establish specific synapses in the nervous system., (Copyright 2003 Wiley-Liss, Inc.)

Purpose: To understand which clinical presentations suggest a diagnosis of choroideremia (CHM)., Methods: Retrospective chart review. Included were patients for whom a clinical diagnosis of CHM was suggested, but either protein analysis or direct sequencing of the CHM gene could not confirm the diagnosis. Clinical presentation, family history and fundus photographs were reviewed., Results: We analyzed protein and DNA samples from members of more than 100 families in which at least 1 member had a clinical diagnosis of CHM. For 26 of these families, the clinical diagnosis of CHM could not be confirmed by laboratory analysis. Relevant clinical information was requested from the referring ophthalmologists so that alternative diagnoses could be considered. Sufficient information was provided for 13 of the 26 families. Four patients were reclassified as having retinitis pigmentosa (RP) from the clinical phenotype; only two clearly had X-linked inheritance. One patient had a syndrome including macular dystrophy, hearing loss, developmental delay and cerebral palsy. One patient was reclassified as having congenital stationary night blindness on the basis of an electronegative electroretinogram and a normal fundus. One patient had hearing loss suggesting Usher syndrome. One patient had signs consistent with cone-rod dystrophy (CRD). Five patients could not be reclassified on the basis of the clinical presentation., Conclusion: RP, Usher syndrome and CRD are clinical phenotypes that may overlap with CHM. Clinical features that suggest CHM include severe chorioretinal atrophy with preservation of the macula, X-linked inheritance and retinal changes in a related female.

A 28-year old woman had an ocular syndrome consisting of congenital lid and punctal anomalies, and corneal and chorioretinal dystrophy without facial dysmorphism. These combined malformations of the ocular adnexae and both anterior and posterior ocular segments have not been previously described and appear to represent a novel syndrome. Direct sequencing of PAX6 and the DNA-binding domain of FOXC1 failed to detect a mutation.

Precise neuronal connectivity during development is subservient to all nervous system functions in adult animals. However, the cellular mechanisms that mastermind this neuronal connectivity remain largely unknown. This lack of fundamental knowledge regarding nervous system development is due in part to the immense complexity of mammalian brain, as cell-cell interactions between defined sets of pre- and postsynaptic partners are often difficult to investigate directly. In this study, we developed a novel model system which has allowed us to reconstruct synapses between identified motor neurons and their target heart muscle cell in a soma-muscle configuration. Utilizing this soma-myocardial cell synapse model, we demonstrate that synapses between somata and heart muscle cells can be reconstructed in cell culture. The soma-myocardial cell synapses required 12-24 h to develop and thus differed temporally from conventional neuromuscular synapses (seconds to a few minutes). We also demonstrate that the synapses are target cell-type-specific and are most likely independent of transmitter phenotypic characteristics of presynaptic neurons., (Copyright 2002 Wiley-Liss, Inc.)