Behavioral effects of environmental enrichment on male and female wistar rats with early life stress experiences.

Exposure to adverse childhood experiences or early life stress experiences (ELSs) increase the risk of non-adaptive behaviors and psychopathology in adulthood. Environmental enrichment (EE) has been proposed to minimize these effects. The vast number of methodological variations in animal studies underscores the lack of systematicity in the studies and the need for a detailed understanding of how enrichment interacts with other variables. Here we evaluate the effects of environmental enrichment in male and female Wistar rats exposed to adverse early life experiences (prenatal, postnatal, and combined) on emotional (elevated plus maze), social (social interaction chamber), memory (Morris water maze) and flexibility tasks. Our results-collected from PND 51 to 64-confirmed: 1) the positive effect of environmental enrichment (PND 28-49) on anxiety-like behaviors in animals submitted to ELSs. These effects depended on type of experience and type of enrichment: foraging enrichment reduced anxiety-like behaviors in animals with prenatal and postnatal stress but increased them in animals without ELSs. This effect was sex-dependent: females showed lower anxiety compared to males. Our data also indicated that females exposed to prenatal and postnatal stress had lower anxious responses than males in the same conditions; 2) no differences were found for social interactions; 3) concerning memory, there was a significant interaction between the three factors: A significant interaction for males with prenatal stress was observed for foraging enrichment, while physical enrichment was positive for males with postnatal stress; d) regarding cognitive flexibility, a positive effect of EE was found in animals exposed to adverse ELSs: animals with combined stress and exposed to physical enrichment showed a higher index of cognitive flexibility than those not exposed to enrichment. Yet, within animals with no EE, those exposed to combined stress showed lower flexibility than those exposed to both prenatal stress and no stress. On the other hand, animals with prenatal stress and exposed to foraging-type enrichment showed lower cognitive flexibility than those with no EE. The prenatal stress-inducing conditions used here 5) did not induced fetal or maternal problems and 6) did not induced changes in the volume of the dentate gyrus of the hippocampus.

Feasibility of whole genome and transcriptome profiling in pediatric and young adult cancers.

The utility of cancer whole genome and transcriptome sequencing (cWGTS) in oncology is increasingly recognized. However, implementation of cWGTS is challenged by the need to deliver results within clinically relevant timeframes, concerns about assay sensitivity, reporting and prioritization of findings. In a prospective research study we develop a workflow that reports comprehensive cWGTS results in 9 days. Comparison of cWGTS to diagnostic panel assays demonstrates the potential of cWGTS to capture all clinically reported mutations with comparable sensitivity in a single workflow. Benchmarking identifies a minimum of 80× as optimal depth for clinical WGS sequencing. Integration of germline, somatic DNA and RNA-seq data enable data-driven variant prioritization and reporting, with oncogenic findings reported in 54% more patients than standard of care. These results establish key technical considerations for the implementation of cWGTS as an integrated test in clinical oncology.

Simulation of the electrical stimulation of the rat brain using sleep frequencies: A finite element modeling approach.

A realistic rat brain model was used to simulate current density and electric field distributions under frequencies characteristic of sleeping states (0.8, 5, and 12 Hz). Two anode-electrode setups were simulated: plate vs. screws-anode, both with a cephalic cathode. Our simulations showed that these frequencies have limited impact on electric field and current density; however, the highest frequency evidenced higher values for both variables. The type of electrode setup had a greater effect on current distribution and induced fields. In that sense, the screws setup resulted in higher values of the modeled variables. The numeric results obtained are within the range of available data for rodent models using the finite elements method. These modeled effects should be analyzed regarding anatomical consequences (depth of penetration of the currents) and purpose of the experiment (i.e., entrainment of brain oscillations) in the context of sleep research.

Improvements in planning lacrimal surgery using DICOM Horos® viewer 3D images.

INTRODUCTION AND OBJECTIVE: The individual anatomic variation of the course of the lacrimal duct and surrounding structures requires the thorough knowledge of its three-dimensional configuration in order to perform the surgery in the safest and most efficient way. The aim of this study was to consider virtual surgical planning in order to improve dacryocystorhinostomies. METHODS: Horos® was used as a viewer and manager of DICOM-format images for multiplanar, three-dimensional (3D) reconstruction when planning 148 first-time lacrimal operations and 26 reoperations by laser endonasal and endocanalicular DCRs. RESULTS: The 3D images of the CT dacryocystography were much better identified than the 2D ones, Horos® showing a statistically significant correlation (P < .0001). Over 98.27% of the images match the programme reconstruction. Less than 1.73% of them showed some discordance due to study distortion. These cases were related to trauma. The intraopearative location of the lacrimal system was very accurate, avoiding complications. CONCLUSIONS: Viewing and studying 3D images, Horos® is a very useful tool for diagnosis and preoperative planning. It is very helpful in complex conditions by marking surgical references, locating the lacrimal sac and controlling the post-operative permeability of the lacrimal system. The information loss produced by the image selection is also avoided. Another great advantage is that the programme is free.

Improvements in planning lacrimal surgery using DICOM Horos® viewer 3D images. / Mejora de la planificación de las cirugías lagrimales a partir de imágenes tridimensionales con el visualizador DICOM Horos®.

INTRODUCTION AND OBJECTIVE: The individual anatomic variation of the course of the lacrimal duct and surrounding structures requires the thorough knowledge of its three-dimensional configuration in order to perform the surgery in the safest and most efficient way. The aim of this study was to consider virtual surgical planning in order to improve dacryocystorhinostomies. METHODS: Horos® was used as a viewer and manager of DICOM-format images for multiplanar, three-dimensional (3D) reconstruction when planning 148 first-time lacrimal operations and 26 reoperations by laser endonasal and endocanalicular DCRs. RESULTS: The 3D images of the CT dacryocystography were much better identified than the 2D ones, Horos® showing a statistically significant correlation (P<.0001). Over 98.27% of the images match the programme reconstruction. Less than 1.73% of them showed some discordance due to study distortion. These cases were related to trauma. The intraopearative location of the lacrimal system was very accurate, avoiding complications. CONCLUSIONS: Viewing and studying 3D images, Horos® is a very useful tool for diagnosis and preoperative planning. It is very helpful in complex conditions by marking surgical references, locating the lacrimal sac and controlling the post-operative permeability of the lacrimal system. The information loss produced by the image selection is also avoided. Another great advantage is that the programme is free.

Mejora de la planificación de las cirugías lagrimales a partir de imágenes tridimensionales con el visualizador DICOM Horos® / Improvements in planning lacrimal surgery using DICOM Horos® viewer 3D images

Introducción y objetivos La variación anatómica individual del trayecto de la vía lagrimal y estructuras adyacentes requiere disponer del mejor conocimiento posible de su configuración tridimensional para afrontar una cirugía con mayor seguridad y eficacia. El objetivo del trabajo fue estudiar la utilidad de la planificación quirúrgica virtual para la mejora en la realización de las dacriocistorrinostomías (DCR). Métodos Se usó el programa Horos® como visualizador y gestor de imágenes en formato DICOM para reconstrucción multiplanar y tridimensional (3D) en la planificación de 148 cirugías lagrimales complejas de primera intención y 26 reintervenciones mediante DCR endocanalicular y endonasal con láser. Resultados Se identificaron más rápidamente y con mayor precisión en las imágenes en 3D de la dacriocistografía-TAC que con placas visualizadas en 2D, con una correlación clínico-radiológica estadísticamente significativa (p<0,0001) a favor de Horos®. Más del 98,27% de las imágenes coincidieron con las reconstrucciones del programa; menos del 1,73% presentaron algún grado de discordancia por distorsiones en el estudio; estos casos fueron los secundarios a traumatismos. La localización intraoperatoria del sistema lagrimal fue muy precisa por la buena orientación, evitando complicaciones. Conclusiones La mejora en la planificación prequirúrgica con utilización sistemática de Horos® para visualización y tratamiento de imágenes en 3D es una herramienta muy útil para el diagnóstico y planificación preoperatoria, facilita una cirugía segura en las patologías complejas, ya que marca referencias quirúrgicas y localiza el saco lagrimal, así como el control postoperatorio de la permeabilidad del aparato lagrimal. Evita la pérdida de información que se produce en la selección de imágenes (AU)

Introduction and objective The individual anatomic variation of the course of the lacrimal duct and surrounding structures requires the thorough knowledge of its three-dimensional configuration in order to perform the surgery in the safest and most efficient way. The aim of this study was to consider virtual surgical planning in order to improve dacryocystorhinostomies. Method Horos® was used as a viewer and manager of DICOM-format images for multiplanar, three-dimensional (3D) reconstruction when planning 148 first-time lacrimal operations and 26 reoperations by laser endonasal and endocanalicular DCRs. Results The 3D images of the CT dacryocystography were much better identified than the 2D ones, Horos® showing a statistically significant correlation (P<.0001). Over 98.27% of the images match the programme reconstruction. Less than 1.73% of them showed some discordance due to study distortion. These cases were related to trauma. The intraopearative location of the lacrimal system was very accurate, avoiding complications. Conclusions Viewing and studying 3D images, Horos® is a very useful tool for diagnosis and preoperative planning. It is very helpful in complex conditions by marking surgical references, locating the lacrimal sac and controlling the post-operative permeability of the lacrimal system. The information loss produced by the image selection is also avoided (AU)

Insertions of antihypertensive peptides and their applications in pharmacy and functional foods.

Hypertension is a worldwide health problem. It is the main cardiovascular risk factor and affects about 31% of the world's adult population. The drugs used to control hypertension may cause side effects; for this reason, there are many investigations focused on searching for alternatives to control or prevent this disease through diet. For example, many peptides have demonstrated antihypertensive effects. The insertion of bioactive peptides is a biotechnological implement used to improve the nutraceutical properties of proteins. This work reviews the current data on the insertion of antihypertensive peptides (AHPs) into food proteins, the systems used to produce the AHPs, the advantages and disadvantages between them, the parameters to produce them at major scales, and their potential applications in pharmacy and functional foods.

Reference genes for RT-qPCR normalisation in different tissues, developmental stages and stress conditions of amaranth.

Studies of gene expression are very important for the identification of genes that participate in different biological processes. Currently, reverse transcription quantitative real-time PCR (RT-qPCR) is a high-throughput, sensitive and widely used method for gene expression analysis. Nevertheless, RT-qPCR requires precise normalisation of data to avoid the misinterpretation of experimental data. In this sense, the selection of reference genes is critical for gene expression analysis. At this time, several studies focus on the selection of reference genes in several species. However, the identification and validation of reference genes for the normalisation of RT-qPCR have not been described in amaranth. A set of seven housekeeping genes were analysed using RT-qPCR, to determine the most stable reference genes in amaranth for normalisation of gene expression analysis. Transcript stability and gene expression level of candidate reference genes were analysed in different tissues, at different developmental stages and under different types of stress. The data were compared using the geNorm, NormFinder and Bestkeeper statistical methods. The reference genes optimum for normalisation of data varied with respect to treatment. The results indicate that AhyMDH, AhyGAPDH, AhyEF-1α and AhyACT would be optimum for accurate normalisation of experimental data, when all treatment are analysed in the same experiment. This study presents the most stable reference genes for normalisation of gene expression analysis in amaranth, which will contribute significantly to future gene studies of this species.

Comparing the Expression of Genes Related to Serotonin (5-HT) in C57BL/6J Mice and Humans Based on Data Available at the Allen Mouse Brain Atlas and Allen Human Brain Atlas.

Brain atlases are tools based on comprehensive studies used to locate biological characteristics (structures, connections, proteins, and gene expression) in different regions of the brain. These atlases have been disseminated to the point where tools have been created to store, manage, and share the information they contain. This study used the data published by the Allen Mouse Brain Atlas (2004) for mice (C57BL/6J) and Allen Human Brain Atlas (2010) for humans (6 donors) to compare the expression of serotonin-related genes. Genes of interest were searched for manually in each case (in situ hybridization for mice and microarrays for humans), normalized expression data (z-scores) were extracted, and the results were graphed. Despite the differences in methodology, quantification, and subjects used in the process, a high degree of similarity was found between expression data. Here we compare expression in a way that allows the use of translational research methods to infer and validate knowledge. This type of study allows part of the relationship between structures and functions to be identified, by examining expression patterns and comparing levels of expression in different states, anatomical correlations, and phenotypes between different species. The study concludes by discussing the importance of knowing, managing, and disseminating comprehensive, open-access studies in neuroscience.

Thigmotactic responses in an open-field.

The goal of the present study was to investigate the role of thigmotaxis (the tendency to remain close to vertical surfaces) in rat exploratory behavior in an open-field. Thigmotaxis was investigated in a parametric way, using 24 experimentally adult naive male Wistar rats (210-230 g). Exploratory behavior was studied in an open-field (N = 12) in 5-min sessions and behavior was analyzed in terms of where it occurred: in areas surrounded by two, one, or no walls. Another group of rats (N = 12) was studied in an open-field with blocks placed near two of the corners so as to make these corner areas surrounded by three walls. The floor of the open-fields was divided into 20-cm squares in order to locate the exact place of occurrence of each behavior. The following behaviors were recorded: entries into the squares, rearings, and groomings. In both types of open-field the rats chose to remain longer in the squares surrounded by the largest possible number of walls. In one of the open-fields, the mean time (seconds) spent in squares surrounded by two walls was longer than the time spent in squares surrounded by one or no walls (37.2, 7.7, and 1.8 s, respectively). In the other open-field, the mean time spent in squares surrounded by three walls was longer than the time spent in squares surrounded by two, one or no walls (41.7, 20.4, 7.0, and 2.6 s, respectively). Other measures presented a similar profile. These results indicate that rats are sensitive to the number of walls in an environment and prefer to remain close to them.

Thigmotactic responses in an open-field

The goal of the present study was to investigate the role of thigmotaxis (the tendency to remain close to vertical surfaces) in rat exploratory behavior in an open-field. Thigmotaxis was investigated in a parametric way, using 24 experimentally adult naive male Wistar rats (210-230 g). Exploratory behavior was studied in an open-field (N = 12) in 5-min sessions and behavior was analyzed in terms of where it occurred: in areas surrounded by two, one, or no walls. Another group of rats (N = 12) was studied in an open-field with blocks placed near two of the corners so as to make these corner areas surrounded by three walls. The floor of the open-fields was divided into 20-cm squares in order to locate the exact place of occurrence of each behavior. The following behaviors were recorded: entries into the squares, rearings, and groomings. In both types of open-field the rats chose to remain longer in the squares surrounded by the largest possible number of walls. In one of the open-fields, the mean time (seconds) spent in squares surrounded by two walls was longer than the time spent in squares surrounded by one or no walls (37.2, 7.7, and 1.8 s, respectively). In the other open-field, the mean time spent in squares surrounded by three walls was longer than the time spent in squares surrounded by two, one or no walls (41.7, 20.4, 7.0, and 2.6 s, respectively). Other measures presented a similar profile. These results indicate that rats are sensitive to the number of walls in an environment and prefer to remain close to them.

Mathematical modelling of microbial growth in ground beef from Argentina. Effect of lactic acid addition, temperature and packaging film.

The effects of: (i) storage temperature (0, 4 and 10°C), (ii) gaseous permeability of the packaging film (polyethylene and EVA SARAN EVA for vacuum packaging), and (iii) natural beef pH (5.6, 5.8 and 6.1) on the growth of different bacteria isolated from beef muscle were examined. The bacteria were Klebsiella, Pseudomonas sp. and Escherichia coli. Microbial growth was modelled using Gompertz and linear equations. The effects of temperature on microbial growth rate (µ) and on lag phase duration were modelled using an Arrhenius type equation. In polyethylene, E. coli was the microorganism, that showed the highest µ values and also the greatest effect of pH on µ, especially in samples stored at 4 and 10°C. In the case of Klebsiella sp., neither pH nor temperature had marked effects on µ and on LPD. In ESE film, µ of all the microorganisms were less affected by pH and temperature than in polyethylene. In ESE film E. coli showed the highest effect of pH on µ, at 4 and 10°C. LPD increased significantly with respect to the values in polyethylene, with Klebsiella sp., showing the highest values of LPD, followed by E. coli. Experiments in ground beef with added lactic acid producing a decrease of the original muscle pH from 6.1 to 5.6 showed that the kinetic parameters of the microbial flora did not differ significantly from those of beef samples in which the original pH was 5.6.

[Complications of the direct endonasal transsphenoidal approach in the management of pituitary adenomas]. / Complicaciones del abordaje endonasal directo transesfenoidal en el manejo de adenomas de hipófisis.

OBJECTIVE: To describe the frequency of complications and complaints caused by direct endonasal transsphenoidal approach used in the resection of pituitary adenomas. PATIENTS AND METHODS: In a retrospective way, we review patients' records with pituitary adenomas, operated by means of direct endonasal transsphenoidal approach, between August 2003 and December 2004. We recollected information about operative and postoperative complications, besides complaints registered in patients' records. RESULTS: 41 patients were included, 23 (56.1%) males and 18 (43.9%) females, with a mean age of 47.7 -/+16.8 years. Operative complications were intrasellar hemorrhage in three patients (7.3%), hypertension in two (4.9%) and cerebrospinal fluid fistula in one (2.4%). On the other hand, postoperative complications were diabetes insipidus (24.4%) in ten cases, anterior pituitary insufficiency (4.9%) in two and sinusitis (2.4%) in one. Nasal congestion was the most common complaint (31.7%) in thirteen patients. CONCLUSIONS: Supported in our results, the direct endonasal transsphenoidal approach tends to present mainly fewer nasal complications and complaints, and in the future it could be considered like the preferred approach for resection of pituitary adenomas.

Complicaciones del abordaje endonasal directo transesfenoidal en el manejo de adenomas de hipófisis / Complications of the direct endonasal transsphenoidal approach in the management of pituitary adenomas

Objetivo. Describir la frecuencia de complicaciones y molestias del abordaje endonasal directo transesfenoidal, utilizado en la resección de adenomas de hipófisis. Pacientes y métodos. En forma retrospectiva, se revisaron los expedientes de pacientes con adenoma de hipófisis, en quienes se realizó el abordaje endonasal directo transesfenoidal, dentro de un periodo comprendido entre Agosto del 2003 y Diciembre del 2004. Se recolectó información sobre las complicaciones trans y postoperatorias, además de molestias postoperatorias registradas en el expediente. Resultados. Se incluyeron 41 pacientes, 23 (56.1%) hombres y 18 (43.9%) mujeres, con una edad promedio de 47.7 ±16.8 años. Dentro de las complicaciones transoperatorias, tres pacientes (7.3%) tuvieron hemorragiaintraselar, dos (4.9%) hipertensión arterial descontrolada y uno (2.4%) fístula de líquido cefalorraquídeo. Entre las complicaciones postoperatorias, la más frecuente fue la diabetes insípida con diez casos (24.4%), dos (4.9%) presentaron insuficiencia hipofisaria anterior y uno (2.4%) sinusitis. La molestia más común fue la congestión nasal en trece pacientes (31.7%).Conclusiones. El abordaje endonasal directo transesfenoidal tiende a presentar menos complicaciones y molestias especialmente nasales, por lo que en un futuro podría ser considerado como el abordaje preferido para la resección de adenomas de hipófisis

Objective. To describe the frequency of complications and complaints caused by direct endonasal transsphenoidal approach used in the resection of pituitary adenomas. Patients and methods. In a retrospective way, were view patients’ records with pituitary adenomas, operated by means of direct endonasal transsphenoidal approach, between August 2003 and December 2004.We recollected information about operative and postoperative complications, besides complaints registered inpatients’ records. Results. 41 patients were included, 23 (56.1%)males and 18 (43.9%) females, with a mean age of 47.7±16.8 years. Operative complications were intrasellar hemorrhage in three patients (7.3%), hypertension in two (4.9%) and cerebrospinal fluid fistula in one(2.4%).On the other hand, postoperative complications were diabetes insipidus (24.4%) in ten cases, anterior pituitary insufficiency (4.9%) in two and sinusitis(2.4%) in one. Nasal congestion was the most common complaint (31.7%) in thirteen patients. Conclusions. Supported in our results, the direct endo nasal transsphenoidal approach tends to present mainly fewer nasal complications and complaints, and in the future it could be considered like the preferred approach for resection of pituitary adenomas

Influencia de los factores ambientales en la severidad del asma bronquial en 2 consultorios médicos de la Familia. Area de Salud Sur Sancti Spíritus. 2004

Se realizó un estudio observacional de tipo descriptivo para caracterizar el asma bronquial en relación con los factores ambientales de riesgo en dos consultorios médicos de la familia del área sur de Sancti Spíritus durante el año 2004, el universo estuvo constituido por 217 pacientes dispenzarizado por asma bronquial de los cuales tenemos como muestra 100 pacientes.Se concluyó que la mayoría de los pacientes presentaron crisis en el año estudiado siendo el mayor número de ellos asmáticos ligeros, presentan un alto nivel de exposición a factores ambientales de la vivienda y en el peridomicilio, más de la mitad de los casos presentan exposición como fumadores pasivos al humo del cigarrillo, la totalidad de los pacientes conocen las medidas de control ambiental para la prevención primaria y menos de la mitad tienen prácticas incorrectas que deterioran su calidad de vida.[AU]

General characterization of noncommercial microbial lipases in hydrolytic and synthetic reactions.

Fourteen noncommercial preparations of microbial lipases were investigated with respect to their catalytic activity for hydrolysis and synthesis of ester bonds. Six of the lipases were derived from microorganisms that have not previously been described as lipase producers, and another four were characterized for the first time. The synthetic reactions were carried out in two solvents of different polarities (n-heptane and acetone) using a series of fatty acids and primary and secondary alcohols with different chain lengths. Under the culture conditions employed, Pseudomonas cepacia produced more active enzyme than the other microorganisms. The lipase preparations produced using Ovadendron sulphureo-ochraceum, Monascus mucoroides, Monascus sp., Fusarium oxysporum, Penicillium chrysogenum, Rhodotorula araucariae, Pseudomonas cepacia, Streptomyces halstedii, and Streptomyces sp.were the most efficient catalysts for hydrolysis at lipid-water interfaces. Enzyme preparations from P. cepacia, Streptomyces sp., S. halstedii, and R. araucariae were good biocatalysts for esterification in the polar medium (acetone). When the lipase preparations with the greatest activity for hydrolytic reactions were excluded, regression analysis of the data for the hydrolytic and synthetic activities of the remaining lipase preparations yielded high multiple correlation coefficients for these reactions in both n-heptane and acetone (R = 0.82 and 0.91, respectively).

Factors associated with chloroquine-induced retinopathy in rheumatic diseases.

Antimalarials are very useful drugs in the treatment of various rheumatic diseases. One of their main side effects is ocular toxicity, specifically retinopathy. Our objective was to identify risk factors associated with chloroquine retinopathy. A single, trained evaluator reviewed patient records with rheumatic diseases. They were taking chloroquine and identified by the ophthalmology department as having retinopathy during their routine eye evaluation. These cases were classified according to clinical evaluation, visual fields and fluorangiographic study. Up to four controls were selected for each case, matched by age, gender, diagnosis and similar time on chloroquine. In all, 34 variables were studied, among these: weight, age, disease duration, keratopathy, total cumulative dose (TCD), mean daily dose (MDD), lean body weight adjusted daily dose (LBWDD) and laboratory tests. Descriptive and inferential statistics comparing cases and controls in all patients and subgroup analysis were carried out. Significance was set at the 0.05 level. Odds ratio and 95% confidence intervals were calculated. Sixteen cases of chloroquine retinopathy were identified, eight patients with rheumatoid arthritis (RA), seven with systemic lupus erythematosus (SLE) and one with dermatomyositis. All were female. Mean age was 47.3 +/- 12.2 years; weight 59.5 +/- 10.7 kg; disease duration 12.8 +/- 6.0 years; time on chloroquine 54.1 +/- 27.8 (min-max: 30-197) months. There was a significant difference in the following variables in all patients: MDD 212.3 +/- 52.6 versus 170 +/- 51.3, p = 0.009; and LBWDD 5 +/- 1 versus 4.2 +/- 1.5, p = 0.03, for cases and controls, respectively. In subgroup analysis the MDD remained significantly different (235.5 +/- 45.8 versus 169.7 +/- 46.1, p = 0.004) only in RA, whereas LBWDD was different both in SLE and RA. Keratopathy increased the risk for retinopathy: OR, 95% CI: 5, 1.4-17.6, p = 0.01. In conclusion, in accordance with previous studies, the MDD, LBWDD and keratopathy were risk factors associated with chloroquine retinopathy. Periodic ophthalmologic evaluations are mandatory.

Effects of septal cholinergic lesion on rat exploratory behavior in an open-field.

The medial septum participates in the modulation of exploratory behavior triggered by novelty. Also, selective lesions of the cholinergic component of the septohippocampal system alter the habituation of rats to an elevated plus-maze without modifying anxiety indices. We investigated the effects of the intraseptal injection of the cholinergic immunotoxin 192 IgG-saporin (SAP) on the behavior of rats in an open-field. Thirty-nine male Wistar rats (weight: 194-230 g) were divided into three groups, non-injected controls and rats injected with either saline (0.5 microl) or SAP (237.5 ng/0.5 microl). Twelve days after surgery, the animals were placed in a square open-field (120 cm) and allowed to freely explore for 5 min. After the test, the rats were killed by decapitation and the septum, hippocampus and frontal cortex were removed and assayed for acetylcholinesterase activity. SAP increased acetylcholinesterase activity in the septum, hippocampus and frontal cortex and decreased the total distance run (9.15 +/- 1.51 m) in comparison to controls (13.49 +/- 0.91 m). The time spent in the center and at the periphery was not altered by SAP but the distance run was reduced during the first and second minutes (2.43 +/- 0.36 and 1.75 +/- 0.34 m) compared to controls (4.18 +/- 0.26 and 3.14 +/- 0.25 m). SAP-treated rats showed decreased but persistent exploration throughout the session. These results suggest that septohippocampal cholinergic mechanisms contribute to at least two critical processes, one related to the motivation to explore new environments and the other to the acquisition and storage of spatial information (i.e., spatial memory).