Raquel Mayordomo Acevedo | Universidad de Extremadura (original) (raw)

Papers by Raquel Mayordomo Acevedo

Journal of Fungi

Onychomycosis is usually diagnosed symptomatically due to the very clear signs caused by the fung... more Onychomycosis is usually diagnosed symptomatically due to the very clear signs caused by the fungus on the nail surface and structure, although the growth of the infecting agent must also be verified by culture in an enriched medium. This procedure is normally lengthy (four weeks), and samples can be contaminated, delaying the prescription of appropriate and effective treatment. Only one previous study has addressed the possibility of using thermography as a diagnostic method for onychomycosis in older people (31–70 years). The present study confirms this use but in individuals aged 18–31 years with incipient mycosis and no pathological signs. Using an FLIR E60 BX camera in a study with 214 samples, we found that men had more onychomycosis than women. We observed a relation between the presence of infection and nail temperature, with a higher temperature in yeast infections (+1 °C) and a lower temperature in dermatophyte infections (−2 °C). A higher temperature by almost 1 °C was al...

Biology

The nail plate is made up of tightly packed keratin-rich cells. Factors such as the special distr... more The nail plate is made up of tightly packed keratin-rich cells. Factors such as the special distribution of the intermediate filaments in each layer (dorsal, intermediate, and ventral), the relative thickness of the layers, and their chemical composition define the characteristics of each nail. The main objective of this study is to determine nail consistency by calculating a predictive model based on elemental composition analysis using scanning electron microscopy. Nail consistency was determined in 57 participants (29 women and 28 men) in two age groups (young people and adults). Elemental composition was analysed in each layer using scanning SEM-EDS, and nail plate thickness was measured by image analysis. A total of 12 elements were detected in nail plates, of which carbon, nitrogen, phosphorus, sulphur, and calcium showed significant differences between layers (p-values ≤ 0.01). The level of calcium in the dorsal layer was the main predictive variable in calculating the predic...

Journal of Renal Care, 2020

Background: Chronic kidney disease (CKD) is a public health disease that affects 15.1% of the adu... more Background: Chronic kidney disease (CKD) is a public health disease that affects 15.1% of the adult population. Although a high prevalence (94.1%) of skin disorders has been detected in people on haemodialysis or with advanced CKD, few studies have analysed foot disorders at initial CKD stages. Objectives: To analyse the prevalence of foot disorders according to CKD stage.

Applied Immunohistochemistry & Molecular Morphology, 2022

The nail plate is one of the essential structures of the nail apparatus and is highly keratinized... more The nail plate is one of the essential structures of the nail apparatus and is highly keratinized, making it difficult to handle this tissue experimentally. Different types of nail consistency were identified by applying distal pressure to the nail plate. To analyze the relationship between the keratins expressed in the nail plate and nail consistency, we chose a sample of 32 adult individuals (age 49.81±3.21 y) with the same number of each sex, who had a similar percentage of nail consistency types (56.25% hard consistency nails and 43.75% soft consistency nails). Immunohistochemical analyses showed that hard consistency nails contain more keratin 17 than soft consistency nails (P=0.026). These novel results allow nail consistency to be defined by the differential expression of keratins in the nail plate, and have potential clinical implications for the diagnosis of possible nail disorders and/or systemic disease.

Journal of Fungi, 2022

Onychomycosis and human papillomavirus (HPV) plantar warts are common in clinical practice. Clini... more Onychomycosis and human papillomavirus (HPV) plantar warts are common in clinical practice. Clinical diagnosis is based on searching for pathognomonic signs and symptoms. However, due to misdiagnosis, podiatrists may unnecessarily prescribe antifungal treatments or burn lesions with chemical agents. The objective of this study was to assess podiatrists’ visual diagnosis of these infections and their willingness to use complementary tests. A 12-item questionnaire was developed to assess visual diagnostic ability. The diagnoses of all lesions were verified before the questionnaire was sent out. The respondents were 415 podiatrists with a range of years of experience. While 86.3% of podiatrists considered complementary tests for onychomycosis necessary, only 21.4% used them regularly. As many as 60.2% would leave a distal subungual onychomycosis untreated based on visual diagnosis. In the case of HPV, only 14.5% of respondents considered complementary tests necessary, although 76.6% wo...

Journal of Fungi, 2021

Onychomycosis is one of the most frequent reasons for visiting podiatrist clinics. Complementary ... more Onychomycosis is one of the most frequent reasons for visiting podiatrist clinics. Complementary tests and the accurate identification of the infectious agents are key issues for a successful treatment of onychomycosis. This is particularly important when lifestyle, age and immunodepressed patients increase the prevalence of non-dermatophyte fungal infection. In this paper, we describe issues related to onychomycosis prevalence in a population of patients, mostly with rural lifestyles, visiting a podiatry clinic in a rural area of Spain. A total of 51 cases were studied with an average age of 65.96 ± 21.28 years (the youngest being 16 years and the oldest being 95 years). Fungal agents were isolated using conventional sampling and microbiological culture techniques. The results obtained with these techniques were compared with the results obtained with a direct methodology using molecular biology, by PCR and nucleotide sequencing of the ITS-5.8S rDNA fragment. The classical culture ...

Applied Sciences, 2021

Kinanthropometry allows us to analyze variations in physical dimensions and body composition. Thi... more Kinanthropometry allows us to analyze variations in physical dimensions and body composition. This study’s objective was to evaluate the kinanthropometric differences based on physical activity performance, depending on whether the lower body or the whole body is more or less potent and the differences with a sedentary population. We analyzed 131 individuals (74 men and 57 women), with an average age of 22.68 ± 2.98 years. We differentiated three populations: sedentary (n = 63), runners (n = 20), and basketball players (n = 48). Measurements and indices were obtained following the international protocol of the International Society for the Advancement of Kinanthropometry (ISAK). The results show differences between the populations regarding weight, height, wingspan, and certain perimeters, diameters, and morphotypes depending on the predominant training type and the sedentary population. These anthropometric measurements will allow the amateur athlete to compare between seasons or o...

INTED2021 Proceedings, 2021

Desde la implantacion completa del plan Bolonia, en el nuevo marco europeo de educacion superior ... more Desde la implantacion completa del plan Bolonia, en el nuevo marco europeo de educacion superior y con la nueva redaccion dada por la Ley Organica 4/2007, de 12 de abril, estructura las ensenanzas universitarias en tres ciclos: Grado, Master y Doctorado, se modifican los estudios de doctorado regulados por el RD 99/2011 de 28 de enero, de validez nacional. Estos cambios dan el valor merecido a la labor investigadora, tanto en la formacion de jovenes investigadores como en etapas postdoctorales. Hasta que finalice el presente curso academico 2012-13, solo existen diplomados en podologia y gracias a la reforma antes explicada, con la existencia de masteres, estos diplomados tienen una salida profesional por esta via y pueden comenzar su carrera investigadora. La dedicacion clinica profesional dentro del ambito podologico hace que no haya un buen conocimiento sobre los requisitos de acceso a la carrera investigadora mediante la diplomatura. Es necesario cursar un master para acceder al...

The International Journal of Developmental Biology, 2001

Natural occurring cell death has been recognised as a feature of normal vertebrate development (G... more Natural occurring cell death has been recognised as a feature of normal vertebrate development (Glucksman, 1951; Saunders, 1966). We have studied the temporal and cellular patterns of cell death in the developing chicken retina using the terminal transferase dUTP nick end-labelling (TUNEL) technique. This technique was combined with other methods to identify dying cells. Fluorescent retrograde tracing of ganglion cells or immunohistochenistry for GABA and TrkA as cell markers were combined with the TUNEL technique. The timing and distribution of dying cells suggest that each neuronal cell type in the retina dies during specific and overlapping periods: ganglion cells first, followed by amacrine cells and bipolar cells. Little cell death could be found among horizontal cells orphotoreceptors. These populations seem to be protected from death. We have previously shown evidence of NGF expression among the horizontal cell population during these stages of development and also a protecti...

The International journal of developmental biology, 1996

Neural cells that will form the neural plate arise from the epiblast cell layer under the influen... more Neural cells that will form the neural plate arise from the epiblast cell layer under the influence of signals produced by organizer centers such as the blastopore dorsal lip in amphibia and its counterpart in amniotes that is the Hensen's Node (HN). Experimental evidence for such affirmation comes mainly from classical manipulation experiments in which the dorsal lip or the HN is transplanted to ectopic places and a new neural axis is induced in the host embryo (Spemann and Mangold, 1924; Waddington, 1932). Nevertheless, the molecular mechanism by which signals produced by the HN produce neural induction is still poorly understood. Several putative molecules have been proposed as candidates for such neural induction, including transcription factors expressed in the HN and secreted molecules that can diffuse along the embryo to induce the formation of the neural plate. Recently, it has been shown that several members of the fibroblast growth factors (FGFs) family are able to ind...

Expert Review of Molecular Diagnostics, 2021

ABSTRACT Introduction Human papillomavirus has been reported as the etiological cause of most cer... more ABSTRACT Introduction Human papillomavirus has been reported as the etiological cause of most cervical cancers and other potentially malignant lesions. It also affects other areas, producing benign tumors on the skin. Plantar warts are a common problem found in clinical practice and share signs and symptoms with other dermatological conditions. Diagnosis of HPV infection remains a hot topic in research. Method The present work systematically reviews the literature on the diagnostic techniques available in the clinical setting for any type of lesion produced by the virus and compares the techniques identified to those found in use for foot lesions. Results Results showed a variety of diagnostic methods, including molecular techniques, which exhibit more sensitivity than other methods but are less frequently applied to plantar lesions, where visual inspection is the most frequent method but can lead to errors. Conclusion The techniques identified need to be applied to plantar lesions to improve differential diagnosis in clinical practice. Expert opinion Research will continue to grow and a proper diagnostic technique for plantar lesions will be available in the near future.

Applied Sciences, 2021

Nail disorders are the most frequent reason for visits to the podiatry clinic. Although they are ... more Nail disorders are the most frequent reason for visits to the podiatry clinic. Although they are not a severe health problem, these types of pathologies have a psychosocial impact on patients, affecting their self-esteem and leading to social and professional self-isolation that can cause anxiety and depression. Laser therapy is considered a potential treatment for nail disorders because it is a fast, easily applied treatment that avoids interaction with medication. However, the literature includes no definitive studies with scientific evidence about the efficacy of laser treatment in traumatic onycholysis, the most frequent clinical sign of nail disorders. Objective: We carried out an objective and quantitative study of the efficacy of laser in treating traumatic onycholysis to provide a new, non-invasive treatment for this pathology, and describe an objective method for its clinical evaluation and evolution. Methods: A strictly repetitive protocol of Nd:YAG 1064 nm laser (PinPoint...

Enfermedades infecciosas y microbiologia clinica (English ed.), 2021

INTRODUCTION Onychomycosis is the main cause of nail alteration. Hepatotoxicity, interference and... more INTRODUCTION Onychomycosis is the main cause of nail alteration. Hepatotoxicity, interference and low adherence to pharmacological treatment are associated. Therefore, our objective was to assess the in vitro effectiveness of tea tree essential oil (less harmful) against main causative agents of these infections. MATERIAL AND METHODS Thrichophyton rubrum and Thrichophyton mentagrophytes were isolated and inoculated at a concentration of 3 × 105 CFU/mL in potato agar dextrose and tea tree essential oil at different concentrations to assess its effect by counting colony forming units and radial growth. RESULTS Trichophyton rubrum growth inhibition was obtained at concentrations higher than 0.04% of the essential tea tree oil (p = 0.004). In the case of Thrichophyton mentagrophytes, inhibition was obtained at 0.02% (p = 0.017), and even complete inhibition at a final concentration of the oil at 0.07%. CONCLUSIONS Tea tree essential oil inhibits the in vitro growth of the fungus and may be a less harmful alternative to the onychomycosis treatment.

Development, 2001

Cell death in the developing retina is regulated, but so far little is known about what factors r... more Cell death in the developing retina is regulated, but so far little is known about what factors regulate the cell death. Several neurotrophic factors and receptors, including the neurotrophins and Trk receptors, are expressed during the critical time. We have studied the developing avian retina with respect to the role of nerve growth factor (NGF) in these processes. Our starting point for the work was that NGF and its receptor TrkA are expressed in a partially overlapping pattern in the inner nuclear layer of the developing retina. Our results show that TrkA and NGF-expressing cells are postmitotic. The first NGF-expressing cells were found on the vitreal side of the central region of E5.5-E6 retina. This pattern changed and NGF-expressing cells identified as horizontal cells were later confined to the external inner nuclear layer. We show that these horizontal cells co-express TrkA and NGF, unlike a subpopulation of amacrine cells that only expresses TrkA. In contrast to the horiz...

Journal of Fungi

Onychomycosis is usually diagnosed symptomatically due to the very clear signs caused by the fung... more Onychomycosis is usually diagnosed symptomatically due to the very clear signs caused by the fungus on the nail surface and structure, although the growth of the infecting agent must also be verified by culture in an enriched medium. This procedure is normally lengthy (four weeks), and samples can be contaminated, delaying the prescription of appropriate and effective treatment. Only one previous study has addressed the possibility of using thermography as a diagnostic method for onychomycosis in older people (31–70 years). The present study confirms this use but in individuals aged 18–31 years with incipient mycosis and no pathological signs. Using an FLIR E60 BX camera in a study with 214 samples, we found that men had more onychomycosis than women. We observed a relation between the presence of infection and nail temperature, with a higher temperature in yeast infections (+1 °C) and a lower temperature in dermatophyte infections (−2 °C). A higher temperature by almost 1 °C was al...

Biology

The nail plate is made up of tightly packed keratin-rich cells. Factors such as the special distr... more The nail plate is made up of tightly packed keratin-rich cells. Factors such as the special distribution of the intermediate filaments in each layer (dorsal, intermediate, and ventral), the relative thickness of the layers, and their chemical composition define the characteristics of each nail. The main objective of this study is to determine nail consistency by calculating a predictive model based on elemental composition analysis using scanning electron microscopy. Nail consistency was determined in 57 participants (29 women and 28 men) in two age groups (young people and adults). Elemental composition was analysed in each layer using scanning SEM-EDS, and nail plate thickness was measured by image analysis. A total of 12 elements were detected in nail plates, of which carbon, nitrogen, phosphorus, sulphur, and calcium showed significant differences between layers (p-values ≤ 0.01). The level of calcium in the dorsal layer was the main predictive variable in calculating the predic...

Journal of Renal Care, 2020

Background: Chronic kidney disease (CKD) is a public health disease that affects 15.1% of the adu... more Background: Chronic kidney disease (CKD) is a public health disease that affects 15.1% of the adult population. Although a high prevalence (94.1%) of skin disorders has been detected in people on haemodialysis or with advanced CKD, few studies have analysed foot disorders at initial CKD stages. Objectives: To analyse the prevalence of foot disorders according to CKD stage.

Applied Immunohistochemistry & Molecular Morphology, 2022

The nail plate is one of the essential structures of the nail apparatus and is highly keratinized... more The nail plate is one of the essential structures of the nail apparatus and is highly keratinized, making it difficult to handle this tissue experimentally. Different types of nail consistency were identified by applying distal pressure to the nail plate. To analyze the relationship between the keratins expressed in the nail plate and nail consistency, we chose a sample of 32 adult individuals (age 49.81±3.21 y) with the same number of each sex, who had a similar percentage of nail consistency types (56.25% hard consistency nails and 43.75% soft consistency nails). Immunohistochemical analyses showed that hard consistency nails contain more keratin 17 than soft consistency nails (P=0.026). These novel results allow nail consistency to be defined by the differential expression of keratins in the nail plate, and have potential clinical implications for the diagnosis of possible nail disorders and/or systemic disease.

Journal of Fungi, 2022

Onychomycosis and human papillomavirus (HPV) plantar warts are common in clinical practice. Clini... more Onychomycosis and human papillomavirus (HPV) plantar warts are common in clinical practice. Clinical diagnosis is based on searching for pathognomonic signs and symptoms. However, due to misdiagnosis, podiatrists may unnecessarily prescribe antifungal treatments or burn lesions with chemical agents. The objective of this study was to assess podiatrists’ visual diagnosis of these infections and their willingness to use complementary tests. A 12-item questionnaire was developed to assess visual diagnostic ability. The diagnoses of all lesions were verified before the questionnaire was sent out. The respondents were 415 podiatrists with a range of years of experience. While 86.3% of podiatrists considered complementary tests for onychomycosis necessary, only 21.4% used them regularly. As many as 60.2% would leave a distal subungual onychomycosis untreated based on visual diagnosis. In the case of HPV, only 14.5% of respondents considered complementary tests necessary, although 76.6% wo...

Journal of Fungi, 2021

Onychomycosis is one of the most frequent reasons for visiting podiatrist clinics. Complementary ... more Onychomycosis is one of the most frequent reasons for visiting podiatrist clinics. Complementary tests and the accurate identification of the infectious agents are key issues for a successful treatment of onychomycosis. This is particularly important when lifestyle, age and immunodepressed patients increase the prevalence of non-dermatophyte fungal infection. In this paper, we describe issues related to onychomycosis prevalence in a population of patients, mostly with rural lifestyles, visiting a podiatry clinic in a rural area of Spain. A total of 51 cases were studied with an average age of 65.96 ± 21.28 years (the youngest being 16 years and the oldest being 95 years). Fungal agents were isolated using conventional sampling and microbiological culture techniques. The results obtained with these techniques were compared with the results obtained with a direct methodology using molecular biology, by PCR and nucleotide sequencing of the ITS-5.8S rDNA fragment. The classical culture ...

Applied Sciences, 2021

Kinanthropometry allows us to analyze variations in physical dimensions and body composition. Thi... more Kinanthropometry allows us to analyze variations in physical dimensions and body composition. This study’s objective was to evaluate the kinanthropometric differences based on physical activity performance, depending on whether the lower body or the whole body is more or less potent and the differences with a sedentary population. We analyzed 131 individuals (74 men and 57 women), with an average age of 22.68 ± 2.98 years. We differentiated three populations: sedentary (n = 63), runners (n = 20), and basketball players (n = 48). Measurements and indices were obtained following the international protocol of the International Society for the Advancement of Kinanthropometry (ISAK). The results show differences between the populations regarding weight, height, wingspan, and certain perimeters, diameters, and morphotypes depending on the predominant training type and the sedentary population. These anthropometric measurements will allow the amateur athlete to compare between seasons or o...

INTED2021 Proceedings, 2021

Desde la implantacion completa del plan Bolonia, en el nuevo marco europeo de educacion superior ... more Desde la implantacion completa del plan Bolonia, en el nuevo marco europeo de educacion superior y con la nueva redaccion dada por la Ley Organica 4/2007, de 12 de abril, estructura las ensenanzas universitarias en tres ciclos: Grado, Master y Doctorado, se modifican los estudios de doctorado regulados por el RD 99/2011 de 28 de enero, de validez nacional. Estos cambios dan el valor merecido a la labor investigadora, tanto en la formacion de jovenes investigadores como en etapas postdoctorales. Hasta que finalice el presente curso academico 2012-13, solo existen diplomados en podologia y gracias a la reforma antes explicada, con la existencia de masteres, estos diplomados tienen una salida profesional por esta via y pueden comenzar su carrera investigadora. La dedicacion clinica profesional dentro del ambito podologico hace que no haya un buen conocimiento sobre los requisitos de acceso a la carrera investigadora mediante la diplomatura. Es necesario cursar un master para acceder al...

The International Journal of Developmental Biology, 2001

Natural occurring cell death has been recognised as a feature of normal vertebrate development (G... more Natural occurring cell death has been recognised as a feature of normal vertebrate development (Glucksman, 1951; Saunders, 1966). We have studied the temporal and cellular patterns of cell death in the developing chicken retina using the terminal transferase dUTP nick end-labelling (TUNEL) technique. This technique was combined with other methods to identify dying cells. Fluorescent retrograde tracing of ganglion cells or immunohistochenistry for GABA and TrkA as cell markers were combined with the TUNEL technique. The timing and distribution of dying cells suggest that each neuronal cell type in the retina dies during specific and overlapping periods: ganglion cells first, followed by amacrine cells and bipolar cells. Little cell death could be found among horizontal cells orphotoreceptors. These populations seem to be protected from death. We have previously shown evidence of NGF expression among the horizontal cell population during these stages of development and also a protecti...

The International journal of developmental biology, 1996

Neural cells that will form the neural plate arise from the epiblast cell layer under the influen... more Neural cells that will form the neural plate arise from the epiblast cell layer under the influence of signals produced by organizer centers such as the blastopore dorsal lip in amphibia and its counterpart in amniotes that is the Hensen's Node (HN). Experimental evidence for such affirmation comes mainly from classical manipulation experiments in which the dorsal lip or the HN is transplanted to ectopic places and a new neural axis is induced in the host embryo (Spemann and Mangold, 1924; Waddington, 1932). Nevertheless, the molecular mechanism by which signals produced by the HN produce neural induction is still poorly understood. Several putative molecules have been proposed as candidates for such neural induction, including transcription factors expressed in the HN and secreted molecules that can diffuse along the embryo to induce the formation of the neural plate. Recently, it has been shown that several members of the fibroblast growth factors (FGFs) family are able to ind...

Expert Review of Molecular Diagnostics, 2021

ABSTRACT Introduction Human papillomavirus has been reported as the etiological cause of most cer... more ABSTRACT Introduction Human papillomavirus has been reported as the etiological cause of most cervical cancers and other potentially malignant lesions. It also affects other areas, producing benign tumors on the skin. Plantar warts are a common problem found in clinical practice and share signs and symptoms with other dermatological conditions. Diagnosis of HPV infection remains a hot topic in research. Method The present work systematically reviews the literature on the diagnostic techniques available in the clinical setting for any type of lesion produced by the virus and compares the techniques identified to those found in use for foot lesions. Results Results showed a variety of diagnostic methods, including molecular techniques, which exhibit more sensitivity than other methods but are less frequently applied to plantar lesions, where visual inspection is the most frequent method but can lead to errors. Conclusion The techniques identified need to be applied to plantar lesions to improve differential diagnosis in clinical practice. Expert opinion Research will continue to grow and a proper diagnostic technique for plantar lesions will be available in the near future.

Applied Sciences, 2021

Nail disorders are the most frequent reason for visits to the podiatry clinic. Although they are ... more Nail disorders are the most frequent reason for visits to the podiatry clinic. Although they are not a severe health problem, these types of pathologies have a psychosocial impact on patients, affecting their self-esteem and leading to social and professional self-isolation that can cause anxiety and depression. Laser therapy is considered a potential treatment for nail disorders because it is a fast, easily applied treatment that avoids interaction with medication. However, the literature includes no definitive studies with scientific evidence about the efficacy of laser treatment in traumatic onycholysis, the most frequent clinical sign of nail disorders. Objective: We carried out an objective and quantitative study of the efficacy of laser in treating traumatic onycholysis to provide a new, non-invasive treatment for this pathology, and describe an objective method for its clinical evaluation and evolution. Methods: A strictly repetitive protocol of Nd:YAG 1064 nm laser (PinPoint...

Enfermedades infecciosas y microbiologia clinica (English ed.), 2021

INTRODUCTION Onychomycosis is the main cause of nail alteration. Hepatotoxicity, interference and... more INTRODUCTION Onychomycosis is the main cause of nail alteration. Hepatotoxicity, interference and low adherence to pharmacological treatment are associated. Therefore, our objective was to assess the in vitro effectiveness of tea tree essential oil (less harmful) against main causative agents of these infections. MATERIAL AND METHODS Thrichophyton rubrum and Thrichophyton mentagrophytes were isolated and inoculated at a concentration of 3 × 105 CFU/mL in potato agar dextrose and tea tree essential oil at different concentrations to assess its effect by counting colony forming units and radial growth. RESULTS Trichophyton rubrum growth inhibition was obtained at concentrations higher than 0.04% of the essential tea tree oil (p = 0.004). In the case of Thrichophyton mentagrophytes, inhibition was obtained at 0.02% (p = 0.017), and even complete inhibition at a final concentration of the oil at 0.07%. CONCLUSIONS Tea tree essential oil inhibits the in vitro growth of the fungus and may be a less harmful alternative to the onychomycosis treatment.

Development, 2001

Cell death in the developing retina is regulated, but so far little is known about what factors r... more Cell death in the developing retina is regulated, but so far little is known about what factors regulate the cell death. Several neurotrophic factors and receptors, including the neurotrophins and Trk receptors, are expressed during the critical time. We have studied the developing avian retina with respect to the role of nerve growth factor (NGF) in these processes. Our starting point for the work was that NGF and its receptor TrkA are expressed in a partially overlapping pattern in the inner nuclear layer of the developing retina. Our results show that TrkA and NGF-expressing cells are postmitotic. The first NGF-expressing cells were found on the vitreal side of the central region of E5.5-E6 retina. This pattern changed and NGF-expressing cells identified as horizontal cells were later confined to the external inner nuclear layer. We show that these horizontal cells co-express TrkA and NGF, unlike a subpopulation of amacrine cells that only expresses TrkA. In contrast to the horiz...