Subjective and objective assessment of fish sperm motility: when the technique and technicians matter.

Fish sperm motility is nowadays considered the best sperm quality biomarker in fish, and can be evaluated both by subjective and computerized methods. With the aim to compare the precision and accuracy of both techniques, fish sperm samples were assessed by subjective methods and by a computer-assisted sperm analysis (CASA-Mot) system, and simultaneously by three different technicians with different degrees of expertise on the sperm quality analysis. Statistical dispersion parameters (CV, coefficient of variation; and RG, range) were estimated in order to determine the precision and accuracy of the techniques and the influence of laboratory staff on sperm motion assessments. Concerning precision, there were not much significant differences between the technical support staff (high, medium, and low experimented technician), and statistical dispersion parameters were quite similar between them independent of the technique used and the sperm motility class analyzed. However, concerning accuracy, experimented technician reported subjective motility values very closed to the values provided by the CASA-Mot system, only 10 percentage points away from the data provided by a CASA-Mot system. However, medium and low experimented technicians often overestimate the CASA-Mot values, and amplitudes up to 30 percentage points were detected in several sperm assessments. To sum up, both the technique (subjective or objective) and the technician (degree of expertise) became key factors in order to reach accurate motility estimations, so the use of both qualified staff and novel CASA-Mot systems seems to be a critical requirement for obtaining satisfying results in fish species with similar motility patterns.

Sperm motility in fish: technical applications and perspectives through CASA-Mot systems.

Although a relatively high number of sperm quality biomarkers have been reported over the years in several fish species, sperm motility is nowadays considered the best biomarker for fish spermatozoa. The first scientific reports focusing on fish sperm motility date from a century ago, but the objective assessment allowed by computer-aided sperm analysis (CASA-Mot) systems was not applied to fish species until the mid-1980s. Since then, a high number of sperm kinetic parameters from more than 170 fish species have been reported in more than 700 scientific articles, covering a wide range of topics, such as sperm physiology, sperm storage, broodstock management, the phenomenon of sperm competition, ecotoxicology and understanding the life cycle of the species. The sperm kinetic parameters provided by CASA-Mot systems can serve as powerful and useful tools for aquaculture and ecological purposes, and this review provides an overview of the major research areas in which fish sperm motility assessment by a CASA-Mot system has been used successfully.

Using specific recombinant gonadotropins to induce spermatogenesis and spermiation in the European eel (Anguilla anguilla).

New specific European eel (Anguilla anguilla) recombinant gonadotropins (aarGths) produced in the ovarian cells of Chinese hamsters (CHO) were used to induce maturation in captive male eels. In the first experiment, five different hormonal treatments were assayed: one group was given a constant dose of recombinant European eel follicle-stimulating hormone (aarFsh; 4 µg/fish) for 9 weeks, and the second group received a constant dose of recombinant European eel luteinizing hormone (aarLh; 2 µg/fish) also for 9 weeks. The other three groups were injected with different combinations of both aarGths (some doses constant, some variable). All five treatments stimulated androgen synthesis, but the increase was more pronounced in the fish treated with a combination of both aarGths. Unlike aarLh, aarFsh alone was able to induce spermiation, the best results were achieved in the fish that were treated with a constant dose of aarFSH and an increasing dose of aarLH, with spermiation being induced (20% motile cells) despite the fact that these fish were immature at the start of the experiment. In order to improve sperm quality, a second experiment was performed. Immature males received three constant doses of aarFsh (2.8, 1.4 or 0.7 µg/fish) and increasing doses of aarLh (every 3 weeks; 1, 2, 6 µg/fish). All the treatments induced spermiation, however the best sperm quality (with ≥50% motile cells) was observed in the males treated with the highest dose of aarFsh. In conclusion, these specific recombinant gonadotropins have demonstrated their capacity to induce spermatogenesis and spermiation in vivo in a teleost fish, the European eel.

Embryonic development of the grass pufferfish (Takifugu niphobles): From egg to larvae.

Tetraodontidae (pufferfish) family members carry the smallest genomes among vertebrates, and these pocket-sized genomes have directly contributed to our understanding of the structure and evolution of higher animals. The grass pufferfish (Takifugu niphobles) could be considered a potential new model organism for comparative genomics and development due to the potential access to embryos, and availability of sequence data for two similar genomes: that of spotted green pufferfish (Tetraodon nigroviridis) and Fugu (Takifugu rubripes). In this study, we provide the first description of the normal embryonic development of T. niphobles, by drawing comparisons with the closely related species cited above. Embryos were obtained by in vitro fertilization of eggs, and subsequent development was monitored at a constant temperature consistent with natural conditions. T. niphobles development was divided into seven periods of embryogenesis: the zygote, cleavage, blastula, gastrula, segmentation, pharyngula, and hatching periods; and stages subdividing these periods are defined based on morphological characteristics. The developmental stage series described in this study aims to provide the utilization of T. niphobles as an experimental model organism for comparative developmental studies.

Fish sperm subpopulations: Changes after cryopreservation process and relationship with fertilization success in tambaqui (Colossoma macropomum).

Fish tambaqui (Colossoma macropomum) is the native Brazilian fish with the highest agricultural production under intensive aquaculture in South America. However, the decrease in the genetic variability in fish farms has become necessary the improvement of cryopreservation process through new statistical studies of spermatozoa (like subpopulation studies). The evaluation of the kinetic data obtained with a computer-assisted sperm analysis system, applying a two-step cluster analysis, yielded in tambaqui three different subpopulations in fresh sperm: SP1, considered as a slow nonlinear subpopulation; SP2, considered as a fast nonlinear subpopulation, and finally; SP3, considered as a fast linear subpopulation. For cryopreserved sperm, the cluster analysis yielded only two sperm subpopulations: SP1', considered as a slow nonlinear subpopulation and SP2', which seemed to be an intermediate subpopulation (showing medium motility and velocity values) merged from SP2 and SP3 obtained from fresh sperm. Coefficients of correlation (r) and determination (r2) between the sperm subpopulations from fresh sperm and the fertilization rates were calculated, and SP2 and SP3 (the fast-spermatozoa subpopulations) showed a high-positive correlation with the fertilization rates (r = 0.93 and 0.79, respectively). In addition, the positive significant correlations found in curvilinear velocity (r = 0.78), straight line velocity (r = 0.57), and average velocity (r = 0.75) indicate that sperm kinetic features seem to be a key factor in the fertilization process in tambaqui, as occur in other fish species.

Refractory ventricular fibrillation during flight / Fibrilación ventricular refractaria en vuelo.

We report the case of a patient who presented an out-of-hospital cardiorespiratory arrest while being transported by the Helicopter Emergency Service, refractory to standard, electrical and medical treatment. The patient recovered spontaneous circulation after 58 minutes with heart arrest and 31 delivered shocks. The reanimation manoeuvres were monitored with capnography (titrated over 20 mmHg EtCO2). Upon arrival at the hospital, the patient went directly to the haemodynamic laboratory where a percutaneous coronary intervention was performed, with a stent in the right coronary artery. The patient was discharged after 8 days without any neurological handicap (cerebral performance category 1).

Fibrilación ventricular refractaria en vuelo / Refractory ventricular fibrillation during flight

Presentamos el caso de un paciente que sufrió una parada cardiorrespiratoria extrahospitalaria en helicóptero sanitario, refractaria a tratamiento médico y eléctrico convencional. El paciente recuperó la circulación espontánea tras 58 minutos en paro cardiaco y 31 descargas eléctricas, estando monitorizado en todo momento de la reanimación cardiopulmonar con capnografía (valores > 20 mm/Hg). A su llegada al hospital, se le realizó una angioplastia primaria, colocándosele un stent en la arteria coronaria derecha. El paciente fue dado de alta hospitalaria, sin secuelas neurológicas (categoría de función cerebral 1) (AU)

We report the case of a patient who presented an out-of-hospital cardiorespiratory arrest while being transported by the Helicopter Emergency Service, refractory to standard, electrical and medical treatment. The patient recovered spontaneous circulation after 58 minutes with heart arrest and 31 delivered shocks. The reanimation manoeuvres were monitored with capnography (titrated over 20 mmHg EtCO2). Upon arrival at the hospital, the patient went directly to the haemodynamic laboratory where a percutaneous coronary intervention was performed, with a stent in the right coronary artery. The patient was discharged after 8 days without any neurological handicap (cerebral performance category 1) (AU)

Subpopulation pattern of eel spermatozoa is affected by post-activation time, hormonal treatment and the thermal regimen.

There has been a marked reduction in natural stocks of eels (genus Anguilla) over the past 60 years, and the culture of eels is still based on the capture of very large quantities of juveniles. It is necessary to close the life cycle in captivity in order to ease the pressure on wild populations. The aims of the present study were to evaluate sperm subpopulations (through cluster analysis of computer-aided sperm analysis data) in the European eel (Anguilla anguilla) and to assess the effects of motility acquisition time after activation (i.e. at 30, 60 and 90s), the thermal regimen (i.e. 10°C (T10) or 15°C (T15) and up to 20°C, or constant at 20°C (T20)) and hormonal treatments (i.e. human chorionic gonadotropin (hCG), recombinant (r) hCG or pregnant mare serum gonadotropin (PMSG)) on these subpopulations. In all cases, we obtained three subpopulations of spermatozoa: low velocity and linear (S1); high velocity with low linearity (S2); and high velocity and linear (S3; considered high quality). Total motility and S1 were affected by acquisition time; thus, 30s is recommended as the standard time for motility acquisition. When eels were kept at 20°C (T20), motility data fitted quadratic models, with the highest motility and proportion of S3 between Weeks 8 and 12 after the first injection. Lower temperatures (T10, T15) delayed spermiation and the obtaining of high-quality spermatozoa (S3), but did not seem to alter the spermiation process (similar subpopulation pattern). Conversely, the hormonal treatments altered both the dynamics of the subpopulation pattern and the onset of spermiation (with PMSG delaying it). Total motility and the yield of S3 with the widely used hCG treatment varied throughout the spermiation period. However, using rhCG allowed us to obtain high-quality and constant motility for most of the study (Weeks 7-20), and the S3 yield was also higher overall (61.8±1.3%; mean ± s.e.m.) and more stable over time than the other hormonal treatments (averaging 53.0±1.4%). Using T20 and rhCG would be more economical and practical, allowing us to obtain a higher number of S3 spermatozoa over an extended time.

Relationship between sperm quality parameters and the fatty acid composition of the muscle, liver and testis of European eel.

This study looks at the correlations that fatty acids have with different tissues in the European eel (Anguilla anguilla L.) during hormonally-induced sexual maturation, with different sperm quality parameters. In order to evaluate the different dynamics of the use of fatty acids, a categorization of the results from each sperm quality parameter (volume, concentration, motility and velocity) was performed. Low and moderate correlations were observed between muscle tissue and some sperm quality parameters but no high correlations were found. Eicosapentaenoic acid (20:5n3, EPA) in the liver seems to have a role in determining the volume of sperm produced. This can be explained by the fact that EPA is a major requirement in the early phases of sperm production (probably as a component of the spermatozoal membrane). In addition, the levels of α-linolenic acid (18:3-n3, ALA) and linoleic acid (18:2-n6, LA) in the liver decreased when sperm motility increased. In all the tissues, a negative correlation was observed between arachidonic acid (20:4n-6, ARA) and the different sperm velocity parameters. The fact that an increase in the consumption of ARA coincides with an increase in the speed of spermatozoa, highlights the important role that this fatty acid plays not only in sperm production, but also in sperm velocity. All this information could prove useful in the development of suitable broodstock diets to improve sperm quality and subsequently, the larval development of this species.

Sperm motility parameters and spermatozoa morphometric characterization in marine species: a study of swimmer and sessile species.

The biodiversity of marine ecosystems is diverse and a high number of species coexist side by side. However, despite the fact that most of these species share a common fertilization strategy, a high variability in terms of the size, shape, and motion of spermatozoa can be found. In this study, we have analyzed both the sperm motion parameters and the spermatozoa morphometric features of two swimmer (pufferfish and European eel) and two sessile (sea urchin and ascidian) marine species. The most important differences in the sperm motion parameters were registered in the swimming period. Sessile species sperm displayed notably higher values than swimmer species sperm. In addition, the sperm motilities and velocities of the swimmer species decreased sharply once the sperm was activated, whereas the sessile species were able to maintain their initial values for a long time. These results are linked directly to the species-specific lifestyles. Although sessile organisms, which show limited or no movement, need sperm with a capacity to swim for long distances to find the oocytes, swimmer organisms can move toward the female and release gametes near it, and therefore the spermatozoa does not need to swim for such a long time. At the same time, sperm morphology is related to sperm motion parameters, and in this study an in-depth morphometric analysis of ascidian, sea urchin, and pufferfish spermatozoa, using computer-assisted sperm analysis software, has been carried out for the first time. A huge variability in shapes, sizes, and structures of the studied species was found using electron microscopy.

The regulation of aromatase and androgen receptor expression during gonad development in male and female European eel.

This research investigated the regulation of aromatase and androgen receptor gene expression in the brain-pituitary-gonad (BPG) axis of male and female European eels (Anguilla anguilla) during induced sexual maturation. Complete A. anguilla aromatase (aa-cyp19a1) and partial androgen receptor α and ß (aa-ara and aa-arb) sequences were isolated, and qPCR assays were validated and used for quantification of transcript levels for these three genes. Expression levels of the genes varied with sex, tissue and stage of maturation. aa-arb was expressed at higher levels than aa-ara in the pituitary and gonad in both sexes, suggesting aa-arb is the physiologically most important androgen receptor in these tissues. In the female brain, a decrease in aa-ara and an increase in aa-cyp19a1 were observed at the vitellogenic stage. In contrast, a progressive increase in all three genes was observed in the pituitary and ovaries throughout gonadal development, with aa-arb and aa-cyp19a1 reaching significantly higher levels at the vitellogenic stage. In the male pituitary, a decrease in aa-arb and an increase in aa-cyp19a1 were observed at the beginning of spermatogenesis, and thereafter remained low and high, respectively. In the testis, the transcript levels of androgen receptors and aa-cyp19a1 were higher during the early stages of spermatogenesis and decreased thereafter. These sex-dependent differences in the regulation of the expression of aa-ara, aa-arb and cyp19a1 are discussed in relation to the role of androgens and their potential aromatization in the European eel during gonadal maturation.

Evaluation of methods to determine sperm density for the European eel, Anguilla anguilla.

European eel, Anguilla anguilla, is a target species for future captive breeding, yet best methodology to estimate sperm density for application in in vitro fertilization is not established. Thus, our objectives were to evaluate methods to estimate European eel sperm density including spermatocrit, computer-assisted sperm analysis (CASA) and flow cytometry (FCM), using Neubauer Improved haemocytometer as benchmark. Initially, relationships between spermatocrit, haemocytometer counts and sperm motility were analysed, as well as the effect of sperm dilution on haemocytometer counts. Furthermore, accuracy and precision of spermatocrit, applying a range of G-forces, were tested and the best G-force used in method comparisons. We found no effect of dilution on haemocytometer sperm density estimates, whereas motility associated positively with haemocytometer counts, but not with spermatocrit. Results from all techniques, spermatocrit, CASA and FCM, showed significant positive correlations with haemocytometer counts. The best correlation between spermatocrit and haemocytometer counts was obtained at 6000 × g (r = 0.68). Of two CASA variants, one or three photographic fields (CASA-1 and CASA-2), CASA-2 showed a very high accuracy to haemocytometer counts (r = 0.93), but low precision (CV: CASA-2 = 28.4%). FCM was tested with and without microfluorospheres (FCM-1 and FCM-2), and relationships to haemocytometer counts were highly accurate (FCM-1: r = 0.94; FCM-2: r = 0.88) and precise (CV: FCM-1 = 2.5; FCM-2 = 2.7%). Overall, CASA-2 and FCM-1 feature reliable methods for quantification of European eel sperm, but FCM-1 has a clear advantage featuring highest precision and accuracy. Together, these results provide a useful basis for gamete management in fertilization protocols.

[Analysis of the control of cardiovascular risk factors in patients with peripheral arterial disease]. / Análisis del control de factores de riesgo cardiovascular en pacientes con enfermedad arterial periférica.

INTRODUCTION: The objective was to determine the percentage of patients with peripheral arterial disease (PAD) with good control of their cardiovascular risk factors (CVRF) (LDL cholesterol, blood pressure and smoke cessation). MATERIAL AND METHODS: Cross-sectional multicentre study. The location was Primary Care and other clinics that typically treat patients with peripheral arterial disease (Internal Medicine, Vascular Surgery, Cardiology, Endocrinology and Nephrology). The first 10 patients with peripheral arterial disease were systematically selected by 440 researchers from all regions. RESULTS: The study included 4087 patients. Blood pressure was controlled in 29.5% of the cases. The frequency of patients with optimal control was significantly better in primary care (p<.01). There was an optimal control of LDL-C levels in 30.4% of patients. Factors associated with optimal control of LDL-C was, being diabetic, stage I of La Fontaine, and being seen by a doctor that was not the primary care physician. Control was worse in women and in smokers. CONCLUSIONS: Primary care physicians better manage patients with hypertension. Patients seen in by a specialist as opposed to primary care are more likely to achieve optimal control of CVRF. The situation is far from the ideal, only 6% achieved optimal control of all CVRF.

Standardization of European eel (Anguilla anguilla) sperm motility evaluation by CASA software.

The development of powerful computer-assisted sperm analysis software has made kinetic studies of spermatozoa possible. This system has been used and validated for several species, but some technical questions have emerged regarding fish sample evaluations (i.e., frame rate, sperm dilution, chamber model, time of analysis, magnification lens, etc.). In the present study, we have evaluated the effects of different procedural and biological settings with the aim to correctly measure sperm quality parameters of the European eel. The use of different chambers did not affect the sperm motility parameters. However, regarding lens magnification, 10× was the most accurate lens, showing the least variation in the acquired data. Similarly, the frame rate setting resulted in a dramatic effect in some sperm kinetic parameters, primarily in terms of curvilinear velocity; we therefore recommend using the camera's highest available frame rate setting. Finally, the reduction in sperm motility over postactivation times suggests that sperm analysis should be performed within the first 60 seconds after activation of the European eel sperm. In conclusion, some protocol variables of sperm analysis by computer-assisted sperm analysis software can affect the measurement of eel sperm quality parameters, and should be considered before directly comparing results obtained by different laboratories. Moreover, because marine fish species show relatively similar features of sperm kinetic parameters, these results could be considered in the evaluation of the motility of sperm from other fish species.

Análisis del control de factores de riesgo cardiovascular en pacientes con enfermedad arterial periférica / Analysis of the control of cardiovascular risk factors in patients with peripheral arterial disease

Introducción. El objetivo del presente estudio es determinar el porcentaje de pacientes con enfermedad arterial periférica (EAP) con un control óptimo de sus factores de riesgo cardiovascular (FRCV) (colesterol unido a las lipoproteínas de baja densidad [c-LDL], presión arterial [PA] y abandono de tabaco). Material y métodos. Estudio descriptivo transversal multicéntrico, realizado en consultas de atención primaria (AP) y de otras especialidades que habitualmente atienden a pacientes con EAP, medicina interna, cirugía vascular (CV), cardiología, endocrinología y nefrología. Selección sistemática de los 10 primeros pacientes con EAP de las consultas de 440 investigadores pertenecientes a todas las comunidades autónomas. Resultados. Se incluyeron en el estudio a 4.087 pacientes. Tenían controlada la PA el 29,5% de los pacientes. La frecuencia de pacientes con control de la PA fue significativamente mejor en consultas de AP (p<0,01). Se observó un control óptimo de los niveles de c-LDL en un 30,4% de los pacientes. Los factores asociados con un control óptimo de este factor fueron el hecho de ser diabético, el encontrarse en estadio I de La Fontaine y el ser atendido por un médico que no fuese de AP, y se controlaba peor en mujeres y en fumadores activos. Conclusiones. Los médicos de AP manejan mejor al paciente hipertenso. Sin embargo, los pacientes atendidos en especialidad frente a AP tienen mayor probabilidad de conseguir un control óptimo de los FRCV. La situación dista de ser la idónea, ya que solo en un 6% se consiguió el control óptimo de todos los FRCV(AU)

Introduction. The objective was to determine the percentage of patients with peripheral arterial disease (PAD) with good control of their cardiovascular risk factors (CVRF) (LDL cholesterol, blood pressure and smoke cessation). Material and methods. Cross-sectional multicentre study. The location was Primary Care and other clinics that typically treat patients with peripheral arterial disease (Internal Medicine, Vascular Surgery, Cardiology, Endocrinology and Nephrology). The first 10 patients with peripheral arterial disease were systematically selected by 440 researchers from all regions. Results. The study included 4087 patients. Blood pressure was controlled in 29.5% of the cases. The frequency of patients with optimal control was significantly better in primary care (p<.01). There was an optimal control of LDL-C levels in 30.4% of patients. Factors associated with optimal control of LDL-C was, being diabetic, stage I of La Fontaine, and being seen by a doctor that was not the primary care physician. Control was worse in women and in smokers. Conclusions. Primary care physicians better manage patients with hypertension. Patients seen in by a specialist as opposed to primary care are more likely to achieve optimal control of CVRF. The situation is far from the ideal, only 6% achieved optimal control of all CVRF(AU)

Variations in the gene expression of zona pellucida proteins, zpb and zpc, in female European eel (Anguilla anguilla) during induced sexual maturation.

Vertebrate eggs are surrounded by an extracellular glycoprotein coat termed zona pellucida (ZP). Integrity of ZP is critical for a correct embryo development. Two zona pellucida protein genes (zpb and zpc) from European eel were characterized, specific qPCR assays developed and their expression in immature males and females carried out. An experimental group of silver-stage eel females was maintained at 18 °C and hormonally induced to sexual maturation by weekly injections of carp pituitary extract during 12 weeks. Changes in zpb and zpc expression during sexual maturation were studied in liver and ovary by qPCR. In liver, no changes were recorded during hormonal treatment, while in ovary expression of both genes decreased during sexual development. These results are a first step in the characterization of ZP in European eel and in the understanding of the mechanism underlying egg envelope formation.

Comparison of two techniques for the morphometry study on gilthead seabream (Sparus aurata) spermatozoa and evaluation of changes induced by cryopreservation.

The development of powerful software has made possible spermatozoa morphology studies. However, some problems have emerged in relation to protocol standardization to compare results from different laboratories. This study was carried out to compare two techniques commonly used (staining vs phase contrast technique) for the morphometry study of gilthead sea bream spermatozoa using an integrated sperm analysis system (ISAS). Spermatozoa morphometry values were significantly affected by the technique used, and phase contrast technique was found to be the more accurate method, showing lower coefficients of variation on spermatozoa morphometry parameters measurements. Moreover, it has been shown that cryopreservation process produces damage in gilthead sea bream spermatozoa, causing negative effects in sperm parameters as spermatozoa morphometry (a decrease in cell volume), motility (from 95 to 68% motile cells) and viability (from 95 to 87% of live cells), being the addition of freezing medium containing cryoprotectant (DMSO) an important factor that caused the morphometry changes.

Heterozygosity-fitness correlations in the gilthead sea bream Sparus aurata using microsatellite loci from unknown and gene-rich genomic locations.

Heterozygosity-fitness correlations (HFC) were assessed for a sample of a gilthead sea bream Sparus aurata population. Two hundred and seventy-one fish were genotyped at 22 known and novel microsatellite loci, from which correlations between the multilocus heterozygosity index (I(MLH) ) and various fitness traits (fork length, mass and specific growth rates) were calculated. Significant global HFCs were found in this sample (0·02 ≤r(2) ≤ 0·08). In addition, all the significant correlations found in this work were negative, indicating that heterozygotes had lower fitness than their homozygote counterparts. Marker location could not explain the observed HFCs. Evidence of inbreeding, outbreeding or population and family structuring was not found in this work. The presence of undetected general effects that may lead to the appearance of HFCs, however, cannot be ruled out. These results seem to be best explained by the occurrence of local effects (due to linkage) or even by possible direct locus advantages.

Síndrome de disfunción cognitiva de perros geriátricos: [revisión] / Cognitive dysfunction syndrome in senior canines: [review]

Durante su vida geriátrica, algunos perros pueden presentar cambios progresivos en su comportamiento habitual, como desorientación, disminución en la interacción con los miembros de la familia, irritabilidad y vocalización excesiva, entre otros. La inespecificidad de estas alteraciones ha hecho que muchas de estas modificaciones comportamentales sean consideradas, erróneamente, como signos típicos del envejecimiento “normal”. No obstante, estas pueden ser reflejo de un proceso patológico cerebral que provoca deterioro progresivo de las funciones cognitivas en perros geriátricos. Recientemente, fue descrita una enfermedad conocida como Síndrome de Disfunción Cognitiva de perros senior o “enfermedad de Alzheimer del perro”, debido a las similitudes clínicas y patológicas con esta enfermedad en humanos. Los animales afectados desarrollan cambios morfofuncionales en diferentes zonas cerebrales, lo que probablemente conduce a la aparición de cambios asociados al decline cognitivo, es decir, disminución en la capacidad de recopilar información, procesarla, retenerla y tomar decisiones, lo que termina provocando efectos deletéreos sobre la calidad de vida del paciente afectado al no lograr desenvolverse normalmente en su medio. Dada la inespecificidad de los signos clínicos, la anamnesis y los test comportamentales han sido considerados como las principales herramientas diagnósticas para identificar este síndrome. Por otra parte, debido a que aún no han sido plenamente establecidos los aspectos etiopatológicos, los mecanismos implicados en el desarrollo de esta neuropatología aún siguen inconclusos, por lo tanto, no son muchas las estrategias terapéuticas disponibles, de las cuales solo la selegilina ha sido aprobada por la FDA.