Series Of Animals Research Articles

Dopamine and motion perception: Unveiling retinal connections in Parkinson's disease

Aims/Purpose: Parkinson's disease (PD) is characterized by degeneration of dopaminergic neurons, which occurs not only in the pars compacta of the sustantia nigra of the midbrain, but also in the retina, where dopaminergic amacrine cells (DAC) have been well characterized. Indeed, parkinsonian patients display visual impairments in early stages of the disease, including motion perception deterioration. Retinal cells responsible of motion perception are the directional selective ganglion cells (DSGC) which receive inhibitory synapses from starburst amacrine cells (SAC). Consequences of DAC degeneration in PD on the functionality of SAC and DSGC is unknown. In this work, we studied the functional connections between DAC and SAC in order to understand the pathophysiological mechanisms that determine the visual dysfunction in PD patients.Methods: Using immunohistochemistry and confocal imaging, we studied the retinal connections between DAC and SAC in wild‐type mice. To determine the type of Dopamine (DA) receptor expressed by SAC, we used transgenic mice whose cells expressing D1 or D2 receptors also express fluorescent markers. Intravitreal injections of 6‐OHDA were performed in a series of animals, followed by immunohistochemistry and optokinetic test.Results: We observed that DAC and SAC have direct synaptic contacts, and that the SAC located in the OFF sublamina of the inner plexiform layer express D2 receptors (D2R) but not D1 receptors. Moreover, depletion of DA in the 6‐OHDA injected mice induced a significant reduction of motion perception.Conclusions: This study shows for the first time in mice that the amacrine retinal cells responsible for perceiving directional selective moving stimuli express D2R. These findings provide new ways of detecting visual impairments in preclinical models of retinal DA degeneration.

Morphological and Ontogenetic Skin Color Changes in the American Alligator (Alligator mississippiensis).

To assess skin color change in alligators, we maintained animals in differently lighted environments and also measured skin colors in an ontogenetic series of wild animals. Juvenile alligators maintained in black enclosures exhibited a gradual lightening of skin color when shifted to white enclosures, and these observed changes were reversible. A histological examination of the skins of alligators maintained in dark tanks showed that the dermis exhibited a dense layer of pigmented cells, while samples from the same animals in light environments exhibited a more diffuse pigmented layer. As alligators grow, they exhibit an ontogenetic loss of stripes that may aid in crypsis and predation. Hatchlings have intense black and yellow vertical stripes that darken with age; adults are a more homogenous black/gray color. Since alligators live in temperate climates and adults have lower surface area/volume ratios, which can be detrimental for the absorption of radiant energy, the darker color of larger animals may also aid in thermoregulation. Alligators at the northern end of their range, with colder climates, exhibited darker skin tones, and the ontogenetic extinction of stripes occurred at a more accelerated rate compared to animals in southern, warmer regions, supporting the idea that latitude-dependent ontogenetic color shift has a role in thermoregulation.

The role of inflammation in ovarian pathology as a predictor of the development of sterility and its correction by inositol medications

Relevance of the research. Ovarian inflammation may be important in the pathology of female reproductive health and may be a predictor of infertility.The purpose of the work. To assess the role of pro- and anti-inflammatory cytokines in the development of inflammation in the ovaries of female rats and to carry out correction with inositol preparations (In); to conduct a retrospective analysis of infertility and its relationship with hormone content.Material and Methods. Experiments were performed on 108 white female Wistar rats, which were divided into 3 series: 1 – control, 3.5-4-month-old rats, 2 – 7.5-8-month-old rats (Age), 3 – hypodynamic stress (Stress). There were 3 groups of animals in each series: A – control, B – inositol (In), B – FT500plus (FT). In and FT were administered intragastrically for 15 days at the rate of 400 mg/kg inositol. The concentration of interleukins (IL) 1beta, 2, 4 and 10 was determined in the blood serum of the animals. A morphological study of the ovaries was carried out. We retrospectively analyzed 137 outpatient records of patients with infertility in the setting of reduced ovarian reserve.Results. Hyperemia of the ovaries was noted in 1 series of animals administered inositol medications. In 1 series of animals, the introduction of In caused an increase in the content of IL-2, and the drug FT led to a decrease in IL-1. Both Age and Stress caused an increase in IL-1beta, and only after hypodynamic stress an increase in IL-10 was noted. When comparing the groups of the 1st series, it was proven that the use of FT for preventive purposes had a greater effect on the body than In. When comparing the results of the 2 series groups, it was found that In and FT had a positive effect on the rats, causing a decrease in pro-inflammatory cytokines and inflammation. When analyzing the groups of 3 series, it was found that with prolonged hypodynamic stress, both In and FT had a positive effect on reducing the inflammatory response in rats.Conclusion. Morphologically, it was established that the use of inositol medications (at the rate of 400 mg/kg) has a positive effect on the morphofunctional state of the ovaries of rats, of rats of all groups. Intragastric administration of FT500plus has a more pronounced effect on the growth and maturation of ovarian cortical follicles compared to inositol.

Role of Pellino-1 in Inflammation and Cardioprotection following Severe Sepsis: A Novel Mechanism in a Murine Severe Sepsis Model †.

Intra-abdominal sepsis is commonly diagnosed in the surgical population and remains the second most common cause of sepsis overall. Sepsis-related mortality remains a significant burden in the intensive care unit despite advances in critical care. Nearly a quarter of the deaths in people with heart failure are caused by sepsis. We have observed that overexpression of mammalian Pellino-1 (Peli1), an E3 ubiquitin ligase, causes inhibition of apoptosis, oxidative stress, and preservation of cardiac function in a myocardial infarction model. Given these manifold applications, we investigated the role of Peli1 in sepsis using transgenic and knockout mouse models specific to this protein. Therefore, we aimed to explore further the myocardial dysfunction seen in sepsis through its relation to the Peli 1 protein by using the loss of function and gain-of-function strategy. A series of genetic animals were created to understand the role of Peli1 in sepsis and the preservation of heart function. Wild-type, global Peli1 knock out (Peli1-/-), cardiomyocyte-specific Peli1 deletion (CP1KO), and cardiomyocyte-specific Peli1 overexpressing (alpha MHC (αMHC) Peli1; AMPEL1Tg/+) animals were divided into sham and cecal ligation and puncture (CLP) surgical procedure groups. Cardiac function was determined by two-dimensional echocardiography pre-surgery and at 6- and 24-h post-surgery. Serum IL-6 and TNF-alpha levels (ELISA) (6 h), cardiac apoptosis (TUNEL assay), and Bax expression (24 h) post-surgery were measured. Results are expressed as mean ± S.E.M. AMPEL1Tg/+ prevents sepsis-induced cardiac dysfunction assessed by echocardiographic analysis, whereas global and cardiomyocyte-specific deletion of Peli1 shows significant deterioration of cardiac functions. Cardiac function was similar across the sham groups in all three genetically modified mice. ELISA assay displayed how Peli 1 overexpression decreased cardo-suppressive circulating inflammatory cytokines (TNF-alpha, IL-6) compared to both the knockout groups. The proportion of TUNEL-positive cells varied according to Peli1 expression, with overexpression (AMPEL1Tg/+) leading to a significant reduction and Peli1 gene knockout (Peli1-/- and CP1KO) leading to a significant increase in their presence. A similar trend was also observed with Bax protein expression. The improved cellular survival associated with Peli1 overexpression was again shown with the reduction of oxidative stress marker 4-Hydroxy-2-Nonenal (4-HNE). Our results indicate that overexpression of Peli1 is a novel approach that not only preserved cardiac function but reduced inflammatory markers and apoptosis following severe sepsis in a murine genetic model.

Changes of electrocardiograms of animals with epinephrine heart damage in influences of stress and castration

Changes of electrocardiograms of animals with epinephrine heart damage in influences of stress and castration

Clustering and classification of vertical movement profiles for ecological inference of behavior

AbstractVertical movements can expose individuals to rapid changes in physical and trophic environments—for aquatic fauna, dive profiles from biotelemetry data can be used to quantify and categorize vertical movements. Inferences on classes of vertical movement profiles typically rely on subjective summaries of parameters or statistical clustering techniques that utilize Euclidean matching of vertical movement profiles with vertical observation points. These approaches are prone to subjectivity, error, and bias. We used machine learning approaches on a large dataset of vertical time series (N = 28,217 dives) for 31 post‐nesting leatherback turtles (Dermochelys coriacea). We applied dynamic time warp (DTW) clustering to group vertical movement (dive) time series by their metrics (depth and duration) into an optimal number of clusters. We then identified environmental covariates associated with each cluster using a generalized additive mixed‐effects model (GAMM). A convolutional neural network (CNN) model, trained on standard dive shape types from the literature, was used to classify dives within each DTW cluster by their shape. Two clusters were identified with the DTW approach—these varied in their spatial and temporal distributions, with dependence on environmental covariates, sea surface temperature, bathymetry, sea surface height anomaly, and time‐lagged surface chlorophyll a concentrations. CNN classification accuracy of the five standard dive profiles was 95%. Subsequent analyses revealed that the two clusters differed in their composition of standard dive shapes, with each cluster dominated by shapes indicative of distinct behaviors (pelagic foraging and exploration, respectively). The use of these two machine learning approaches allowed for discrete behaviors to be identified from vertical time series data, first by clustering vertical movements by their movement metrics (DTW) and second by classifying dive profiles within each cluster by their shapes (CNN). Statistical inference for the identified clusters found distinct relationships with environmental covariates, supporting hypotheses of vertical niche switching and vertically structured foraging behavior. This approach could be similarly applied to the time series of other animals utilizing the vertical dimension in their movements, including aerial, arboreal, and other aquatic species, to efficiently identify different movement behaviors and inform habitat models.

“Authentic provenance”

Nineteenth-century zoological collections consisted of large series of animals, which had been trapped, uprooted, hunted, killed, put into containers, dried, and preserved. From distant far-flung outposts overseas, colonial collections were shipped to central metropolitan institutions where they were claimed as a crucial part of the understanding of global biodiversity. Knowledge about nature was reliant on such scientific specimens and, therefore, dependent on fieldwork, which comprised much more than the act itself of sampling nature. Collecting from the field is a matter of access to places, materials, tools, and people with the know-how to find, capture, and interpret nature and, often, to prepare animals as specimens. Although different layers of labor, expertise, and knowledge lie behind zoological collections, much of it was produced and negotiated outside museums’ walls. Using the historical documentation of zoological collections in the Museu Nacional de Lisboa in the second half of the nineteenth century as a case study, this paper highlights the role of colonial suppliers as mediators for the museum’s agenda while adjusting to local circumstances and maintaining their own personal goals. Studies of historical provenance have clarified not only how zoological specimens were gathered and collated but also how their geographical origin was used as a mechanism of centralization of authority.

Children prefer to learn from smart devices, but do not trust them more than humans

Despite the rise in prevalence of voice-activated smart devices and their potential to influence how young children learn about the world, we know little about how children interact with and learn from these devices. In the current study, 5- to 6-year-old children (n=30) were asked whether they wanted to learn more information about a series of obscure animals from an Amazon Echo or a human confederate. After informants gave contradictory answers, participants were asked whose information they trusted. Children significantly preferred to request information from the Amazon Echo but showed no preference with regards to whose information they endorsed. Furthermore, performance was not affected by technology experience. While children enjoy interacting with smart devices, they may not believe the information that they receive.

Fuera de camino pero dentro del sentido: La lectura de los animales en la tercera salida de don Quijote

It is well known that the excess of reading transformed the hidalgo from La Mancha. Reading too many books impacted his vision and created a perturbing reading of the surrounding reality, including animals. Indeed, the second part of Don Quixote appears populated by animals in a much more powerful and meaningful way than in part one. This essay analyzes the series of animals that Don Quixote encounters on his third sally and suggests that the symbolic reading he does turns them into milestones in his chivalric career (a reflection of his fears, hopes, joys, and failures).

Fuera de camino pero dentro del sentido: La lectura de los animales en la tercera salida de don Quijote

It is well known that the excess of reading transformed the hidalgo from La Mancha. Reading too many books impacted his vision and created a perturbing reading of the surrounding reality, including animals. Indeed, the second part of Don Quixote appears populated by animals in a much more powerful and meaningful way than in part one. This essay analyzes the series of animals that Don Quixote encounters on his third sally and suggests that the symbolic reading he does turns them into milestones in his chivalric career (a reflection of his fears, hopes, joys, and failures).

Kinetics of morphofunctional changes in the center of inflammation of pulmonary tissue caused by staphylococcus aureus

In three experimental series of experimental animals caused by inflammation model with a standard strain of Staphylococcus aureus. (Strain WOOD -46). Held control of the morphological and functional changes in the lung tissue at different times from the beginning of the introduction of Staphylococcus aureus. The histological method was used. The observations indicate a dose-dependent morphological changes in the lung tissue with inflammation caused by various doses of the standard Staphylococcus aureus.

Focality and prospective memory in preschool children

We examined the influence of prospective memory (PM) cue focality in a sample of preschool children. Prior investigations in older populations indicated that focal targets were associated with enhanced PM performance, perhaps through more automatic retrieval processes. Importantly, this influential variable has not been thoroughly explored in younger samples. Over three test sessions, preschool children completed a memory task where they were shown a series of animals. During retrieval, participants were shown all of the animals except for one, and they had to name the missing animal. While engaged in this task, participants in the focal PM condition were instructed to remove particular animals (e.g., spider) from the game if they saw them. In the nonfocal condition, participants were told to remove any animal that was entirely one color (e.g., black) if they saw them during the game. The results demonstrated no difference in PM remembering between focal and nonfocal conditions. These results suggest that the effects of focality may not be present at the beginning stages of PM development. The implications for PM retrieval processes also are discussed.

Bats and diseases in the context of the SARS-CoV-2 pandemic and magic medicine practices: perceptions, prejudices and realities (historical, zoological, epidemiological and ethnocultural interferences)

The pandemic caused by the SARS-CoV-2 virus has multiple unknown sides, various hypotheses regarding the causes of this plague being launched. One of the hypotheses, circulating both in science and in the media, concerns a series of animals, carriers of the SARS-CoV-2 virus, subsequently transmitted through other animals to humans. Bats are among the possible mammals that are targeted in such contamination, but there is no clear evidence in this regard. Chiroptera play an important role in ecology, economy and human life, contributing to the protection and pollination of plants, the eradication of harmful insects in agriculture, the development of new remedies and pharmacological preparations, including anticoagulants. In Romanian folklore, bats have an evil image, a fact explained by their nocturnal way of life. Some practices of magical medicine were based on the use of certain parts of the bat’s body (blood, wings, paws, down) to treat certain diseases and mental ailments. The bat appears in children’s folklore, in stories and riddles, being a creature through which the little ones got to know the fauna and learned to hate the petty qualities of the human being. In the cultures of the world, the bat is ubiquitous in folklore, magic medicine and art

MultiSegVA: Using Visual Analytics to Segment Biologging Time Series on Multiple Scales.

Segmenting biologging time series of animals on multiple temporal scales is an essential step that requires complex techniques with careful parameterization and possibly cross-domain expertise. Yet, there is a lack of visual-interactive tools that strongly support such multi-scale segmentation. To close this gap, we present our MultiSegVA platform for interactively defining segmentation techniques and parameters on multiple temporal scales. MultiSegVA primarily contributes tailored, visual-interactive means and visual analytics paradigms for segmenting unlabeled time series on multiple scales. Further, to flexibly compose the multi-scale segmentation, the platform contributes a new visual query language that links a variety of segmentation techniques. To illustrate our approach, we present a domain-oriented set of segmentation techniques derived in collaboration with movement ecologists. We demonstrate the applicability and usefulness of MultiSegVA in two real-world use cases from movement ecology, related to behavior analysis after environment-aware segmentation, and after progressive clustering. Expert feedback from movement ecologists shows the effectiveness of tailored visual-interactive means and visual analytics paradigms at segmenting multi-scale data, enabling them to perform semantically meaningful analyses. A third use case demonstrates that MultiSegVA is generalizable to other domains.

Экспериментальная оценка воздействия неблагоприятных факторов титано-магниевого производства

Іn order to clarify the nature of pathological changes in animals that develop under the influence of a complex of toxic gases and dust (titanium dioxide aerosol, titanium metal dust, titanium tetrachloride and its hydrolysis products, as well as chlorine and phosgene), we performed experimental studies directly in the conditions of titanium-magnesium production. This approach, from our point of view, can create the most profitable experimental model that allows for the maximum completeness of the corresponding clinical and experimental Parallels. Therefore, a series of experimental animals were placed on the territory of the three main workshops of JSC «CC TMK». The animals were placed in specially made cages of 25-26 heads each, which were installed at the level of the human respiratory system. Experimental animals of the control series of the experiment were kept on the territory of the plant, but at a considerable distance from the main production shops in a separate, clean, well-ventilated room. The animals of the control group were slaughtered at the same time as the experimental animals. These studies help in the development of evidence-based measures to improve the health of workers engaged in harmful working conditions. In such production conditions, workers often had acute respiratory infections, chronic bronchitis, etc.the degree of retention of compounds containing chlorine anion (chlorine, hydrogen chloride, titanium tetrachloride, phosgene, magnesium dihloride) was relatively high and ranged from 39-85%. At the same time, higher indicators of the degree of delay in all the main workshops were usually observed for gaseous substances (chlorine, hydrogen chloride, phosgene), which is probably due to their good solubility.

Intermittent hypoxia induces premature adipose tissue senescence leading to cardiac remodeling

Obstructive sleep apnea is a growing worldwide health problem. The landmark feature of OSA is a chronic intermittent hypoxia (CIH) responsible for multiple organ damages including heart diseases. CIH profoundly alters both visceral adipose tissue (VAT) and heart structures and functions, but little is known regarding their interactions in the context of CIH. We recently showed that VAT senescence drives myocardial alterations through the release of profibrotic factors in aged mice. Thus, we aim at demonstrating that CIH induces a premature vWAT senescent phenotype, responsible for subsequent heart dysfunction. In a first series of animals, ten-week old C57BL6 male mice ( n = 10/group) were exposed to 14 days CIH protocol (8 hours daily, 5–21% cyclic inspired oxygen fraction, 60 seconds per cycle). In another series, mice were submitted to VAT surgical lipectomy or sham-surgery ( n = 10/group) and then exposed to the same CIH protocol. VAT and heart were assessed by histology for fibrosis (Sirius red), cell hypertrophy (wheat-germ agglutinin) and reactive oxygen species (ROS) (4-HNE), and markers of senescence (p16, p21, p53), inflammation (CD68, Tnfa, Serpine1), fibrosis (Col1a1) and hypertrophy were also evaluated by RT-qPCR and western blot. CIH induced an increased macrophage infiltration in VAT, along with an increased expression of senescence markers, ROS production and gene expression of inflammatory and fibrogenic markers. This was associated with CIH-induced myocardial interstitial fibrosis and upregulation of profibrotic gene expression in myocardium. Interestingly, VAT lipectomy prevented CIH-induced myocardial fibrosis. Short-term exposure to CIH is sufficient to induce both VAT remodelling, characterized by oxidative stress, inflammation and fibrosis, and cardiac interstitial fibrosis that was prevented by VAT lipectomy. This strongly suggest a causal crosstalk between CIH-induced VAT senescence and cardiac remodeling.

Correction with thiocetam of lead nanoparticles influence on morpho-functional status of rat liver

Abstract The aim of this paper is to investigate the influence of Thiocetam on morphological changes in the liver of rats and on biochemical changes in their blood after exposure to lead nanoparticles and compounds. The liver is an organ that performs a number of functions, such as the synthesis of enzymes, hormones, plasma components and the neutralization of toxins. It is involved in many metabolic processes in the body. In undertaking this, colloidal solutions of lead sulphide nanoparticles at dosages 10 nm and 30 nm were injected into two groups of rats, PbSnano1 and PbSnano2, respectively, while group Pb(NO3) received subcutaneously a solution of lead nitrate in ion form in a dose of 1.5 mg/kg (0.94 mg/kg lead, in lead equivalent). After 60 administrations (12 weeks) of the studied substances, the exposure was discontinued and the animals were observed for 18 weeks. Subsequently, half of each group received Thiocetam by injection (for 6 weeks at a dose of 250 mg/kg) while the other half did not. We then assessed the mean body weight, absolute and relative liver weight, blood biochemistry values (total protein, albumin, glucose, total lipids, cholesterol, triglycerides levels in blood serum) and morphological changes in hepatocytes (morphological slides, nuclei cross-sectional area and cytoplasm cross-sectional area). The outcome of this work showed that the mean body weight of animals exposed to nanoparticles with Tiocetam did not differ from that of animals exposed to nanoparticles without pharmacological correction, but relative liver weight was statistically significantly higher than the corresponding values in rats without pharmacological correction. The morphological picture in all study group animals was characterized by the normalization of microvessel blood filling, structure of hepatic plates, disappearance of infiltration with lymphocytes and histiocytes. No dystrophic changes in hepatocytes were found. All this indicates the feasibility of preventive measures during exposure to lead nanoparticles, by administering Thiocetam. In both series of animals exposed to lead nanoparticles (PbSnano1 and PbSnano2), the cross-sectional area of the hepatocytes cytoplasm and the cross-sectional area of the hepatocytes nuclei were smaller than just after exposure, but in the series with Thiocetam adminstration, all the values did not differ from those in the control.

Histomorphometric assessment of changes in the parenchyma of the pancreas under the influence of hyperosmolar dehydration

The purpose of the work is to study the features of histomorphometric changes in the pancreas of rats under conditions of hyperosmolar dehydration.Material and methods. The experiment was conducted on 40 adult white malerats. The control series of animals was 10 rats, the experimental series was divided depending on the degree of dehydration into 3 groups of 10 rats each.Results. Under conditions of hyperosmolar dehydration, we found the following statistically significant changes. An increase in acinus area was observed with mild dehydration and amounted to 39.9%; pancreatic islets – with moderate and severe degrees of 51,6 % and 45.9 %. The area of exocrine pancreatocytes decreased with moderate and severe degrees by 29,6 % and 35,9 %, with an increase in the area of their nuclei by 46,2 % under conditions of severe dehydration.Conclusions. Changes in the parenchyma of the pancreas and microvasculature progress in direct proportion to the increase in the severity of dehydration.

The amygdala of the common shrew, guinea pig, rabbit, fox and pig: five flavours of the mammalian amygdala as a consequence of clade-specific mosaic-like evolution.

The amygdala is a part of neural networks that contribute to the regulation of emotional behaviours and emotional learning, stress response, and olfactory, pheromonal and reproductive functions. All these various functions are processed by the three main functional systems, frontotemporal, autonomic and olfactory, which are derived from different telencephalic sources (claustrum, striatum and olfactory cortex) and are represented, respectively, by the basolateral complex (BLC), the central complex (CC) and corticomedial complex (CMC) of the amygdala. The question arises of how these three functional systems evolved during mammalian phylogeny to fit the amygdala to specific needs of various animals. In the present study, we provide quantitative information regarding the individual volumes and neuron numbers in the BLC, CC and CMC of the common shrew, guinea pig, rabbit, fox and pig, a series of animals arranged according to increasing size and complexity of the brain. The results show that, in this series of animals, the BLC underwent a gradual size increase in volume and number of neurons, whereas the CMC was gradually reduced with regard to both these measures. The CC was more or less conserved across studied species. For example, the volume of the amygdala in pigs is ~250 times larger than that in shrews and it also has almost 26 times as many neurons as the amygdala of shrews. However, the volumes of the BLC, CC and CMC were ~380, 208 and 148 times larger, respectively, in pigs than in shrews. The number of neurons in these three regions was ~38, 23 and 20 times greater, respectively, in pigs than in shrews. The results also show striking morphometric similarities of the amygdala in the guinea pig and rabbit as well as fox and pig. For example, the percentages of neurons in the fox and pig are 42.23% and 42.78%, respectively, for the BLC, 16.64% and 16.58%, respectively, for the CC, and 41.12% and 40.64%, respectively, for the CMC. In conclusion, our results indicate that the amygdala does not evolve as a single unit but, instead, the three main functional systems evolved independently, which suggests that brain structures with major functional links evolve together independently of evolutionary changes in other unrelated structures. The size progression of the BLC parallels the size progression of the neocortex with which it is strongly functionally linked, whereas the CMC is strongly connected to olfactory regions, and all these structures follow the same regression course. Remarkable morphometric similarity of the amygdala in the guinea pig and rabbit as well as in the fox and pig, however, suggest that there must also be another mechanism shaping the morphology of the amygdala and the brain during evolution. The gradual nature of size changes in the BLC and CMC support this hypothesis as well.

High Sensitivity and Specificity Detection of Protoporphyrin IX Fluorescence in Glioblastoma by Means of Simultaneous 2-photon Microscopy and Stimulated Raman Histology

Abstract INTRODUCTION Extent of resection has been recognized as an important predictor for survival in glioblastoma (GBM) patients. The detection of residual infiltrating tumor at the time of surgery can be challenging. 5-aminolevulinic acid (5-ALA) has recently been approved for the visualization of malignant tissue during glioma surgery. A limitation of such optical contrast agents when imaged with standard operating microscopes is sensitivity and specificity for detecting malignant tissue with low cellularity at the infiltrative tumor margin or in low-grade gliomas. METHODS We present the use of a clinical laser microscopy system (Invenio Imaging Inc, NIO Laser Imaging System) to image fresh biopsy specimens in the OR in under 3 min based on Stimulated Raman Histology. The system was modified to simultaneously detect the 2-photon fluorescence signal of 5-ALA induced protoporphyrin IX (PpIX) fluorescence with a highly sensitive photo-multiplier tube (Hamamatsu Inc.) and a 640/70 nm emission filter (Chroma Inc.). Images were quantified with a custom cell-counter for PpIX fluorescence positive cells developed in Python. The system was validated with both 5-ALA treated and untreated invasive, human GBM xenografts. RESULTS We demonstrate for the first time the detection of PpIX positive tumor cells with single-cell sensitivity. We also demonstrate that co-use with stimulated Raman scattering to image the tissue, histology can identify auto-fluorescent background that is not associated with cells. Finally, we compared the accuracy of the automated cell-counter to manual cell-counting in a series of animals (10). CONCLUSION The combination of 2-photon fluorescence imaging of PpIX with stimulated Raman histology provides unprecedented sensitivity and specificity at the cell level. This approach may provide intraoperative real-time information for tumor detection at the infiltrative margin for maximal safe resection.