Course and Relation of the Facial Vessels-An Anatomical Study.

Background and Objectives: Facial vascular anatomy plays a pivotal role in both physiological context and in surgical intervention. While data exist on the individual course of the facial artery and vein, to date, the spatial relationship of the vasculature has been ill studied. The aim of this study was to assess the course of facial arteries, veins and branches one relative to another. Materials and Methods: In a total of 90 halved viscerocrania, the facial vessels were injected with colored latex. Dissection was carried out, the relation of the facial vessels was studied, and the distance at the lower margin of the mandible was measured. Furthermore, branches including the labial and angular vessels were assessed. Results: At the base of the mandible, the facial artery was located anterior to the facial vein in all cases at a mean distance of 6.2 mm (range 0-15 mm), with three cases of both vessels adjacent. An angular vein was present in all cases, while an angular artery was only present in 34.4% of cases. Conclusions: The main trunk of the facial artery and vein yields a rather independent course, with the facial artery always located anterior to the vein, while their branches, especially the labial vessels, demonstrate a closer relationship.

Distribution of Cleaved SNAP-25 in the Rat Brain, following Unilateral Injection of Botulinum Neurotoxin-A into the Striatum.

In Parkinson's disease, hypercholinism in the striatum occurs, with the consequence of disturbed motor functions. Direct application of Botulinum neurotoxin-A in the striatum of hemi-Parkinsonian rats might be a promising anticholinergic therapeutic option. Here, we aimed to determine the spread of intrastriatally injected BoNT-A in the brain as well as the duration of its action based on the distribution of cleaved SNAP-25. Rats were injected with 1 ng of BoNT-A into the right striatum and the brains were examined at different times up to one year after treatment. In brain sections immunohistochemically stained for BoNT-A, cleaved SNAP-25 area-specific densitometric analyses were performed. Increased immunoreactivity for cleaved SNAP-25 was found in brain regions other than the unilaterally injected striatum. Most cleaved SNAP-25-ir was found in widespread areas ipsilateral to the BoNT-A injection, in some regions, however, immunoreactivity was also measured in the contralateral hemisphere. There was a linear relationship between the distance of a special area from the injected striatum and the time until its maximum averaged immunoreactivity was reached. Moreover, we observed a positive relationship for the area-specific distance from the injected striatum and its maximum immunoreactivity as well as for the connection density with the striatum and its maximum immunoreactivity. The results speak for a bidirectional axonal transport of BoNT-A after its application into the striatum to its widespread connected parts of the brain. Even one year after BoNT-A injection, cleaved SNAP-25 could still be detected.

Ex Vivo Micro-CT in Ophthalmology: Preparation and Contrasting for Non-invasive 3D-Visualisation. / Ex-vivo-Mikro-CT in der Augenheilkunde: Probenbehandlung und -kontrastierung für die 3D-Darstellung.

X-ray-based micro-computed tomography (micro-CT) is a largely non-destructive imaging method for the visualisation and analysis of internal structures in the ex vivo eye and affords high resolution. In contrast to other high-resolution imaging methods, micro-CT enables spatial recording of larger and more complex tissue structures, such as the anterior chamber of the eye. Special contrasting methods help to enhance the absorption properties of soft tissue, that is otherwise only weakly radiopaque. Critical point drying (CPD), as primarily used in scanning electron microscopy, offers an additional tool for improving differential contrast properties in soft tissue. In the visualisation of intraosseous soft tissue, such as the efferent lacrimal ducts, sample treatment by decalcification with ethylenediaminetetraacetic acid and subsequent CPD provides good results for micro-CT. Micro-CT can be used for a wide range of questions in 1. basic research, 2. application-related studies in ophthalmology (e.g. evaluation of the preclinical application of microstents for glaucoma treatment or analysis of the positioning of intraocular lenses) but also 3. as a supplement to ophthalmological histopathology.

The Course and Variation of the Facial Vein in the Face-Known and Unknown Facts: An Anatomical Study.

Background and Objectives: The facial vein is the main collector of venous blood from the face. It plays an important role in physiological as well as pathological context. However, to date, only limited data on the course and tributaries of the facial vein are present in contemporary literature. The aim of this study was to provide detail on the course and the tributaries of the facial vein. Materials and Methods: In 96 sides of 53 body donors, latex was injected into the facial vein. Dissection was carried out and the facial vein and its tributaries (angular vein, ophthalmic vein, nasal veins, labial veins, palpebral veins, buccal and masseteric veins) were assessed. Results: The facial vein presented a textbook-like course in all cases and crossed the margin of the mandible anterior to the masseter in 6.8% of cases, while being located deep to the zygomaticus major muscle in all cases and deep to the zygomaticus minor in 94.6% of cases. Conclusions: This work offers detailed information on the course of the facial vein in relation to neighboring structures, which shows a relatively consistent pattern, as well as on its tributaries, which show a high variability.

New Insights into the Communications of the Facial Vein with the Dural Venous Sinuses.

Background and Objectives: Anastomoses of the extracranial and intracranial venous system have been described in the literature. The presence of such anastomoses may facilitate a possible spread of infection into the dural venous sinuses. However, the frequency and relevance of such anastomoses is highly debated. The aim of this study was to quantify frequencies of anastomoses between the facial vein and the dural venous sinuses. Materials and Methods: In 32 sides of 16 specimens, latex was injected into the facial vein. Dissection was carried out to follow and described these anastomoses, yielding the presence of latex in the intracranial venous system. Results: In 97% of cases, a dispersal of latex into the cavernous sinus as well as anastomoses was observed. A further dispersal of latex into other dural venous sinuses was found at rates ranging between 34% (transverse sinus)-88% (superior petrosal sinus), respectively. Conclusions: The presence of anastomoses between the extracranial and intracranial venous system in a majority of cases needs to be considered when dealing with pathologies as well as procedures in the facial region.

Transmembrane protein 119 is neither a specific nor a reliable marker for microglia.

Microglia are the resident innate immune cells of the central nervous system (CNS) parenchyma. To determine the impact of microglia on disease development and progression in neurodegenerative and neuroinflammatory diseases, it is essential to distinguish microglia from peripheral macrophages/monocytes, which are eventually equally recruited. It has been suggested that transmembrane protein 119 (TMEM119) serves as a reliable microglia marker that discriminates resident microglia from blood-derived macrophages in the human and murine brain. Here, we investigated the validity of TMEM119 as a microglia marker in four in vivo models (cuprizone intoxication, experimental autoimmune encephalomyelitis (EAE), permanent filament middle cerebral artery occlusion (fMCAo), and intracerebral 6-hydroxydopamine (6-OHDA) injections) as well as post mortem multiple sclerosis (MS) brain tissues. In all applied animal models and post mortem MS tissues, we found increased densities of ionized calcium-binding adapter molecule 1+ (IBA1+ ) cells, paralleled by a significant decrease in TMEM119 expression. In addition, other cell types in peripheral tissues (i.e., follicular dendritic cells and brown adipose tissue) were also found to express TMEM119. In summary, this study demonstrates that TMEM119 is not exclusively expressed by microglia nor does it label all microglia, especially under cellular stress conditions. Since novel transgenic lines have been developed to label microglia using the TMEM119 promotor, downregulation of TMEM119 expression might interfere with the results and should, thus, be considered when working with these transgenic mouse models.

Organ Weights in NPC1 Mutant Mice Partly Normalized by Various Pharmacological Treatment Approaches.

Niemann-Pick Type C1 (NPC1, MIM 257220) is a rare, progressive, lethal, inherited autosomal-recessive endolysosomal storage disease caused by mutations in the NPC1 leading to intracellular lipid storage. We analyzed mostly not jet known alterations of the weights of 14 different organs in the BALB/cNctr-Npc1m1N/-J Jackson Npc1 mice in female and male Npc1+/+ and Npc1-/- mice under various treatment strategies. Mice were treated with (i) no therapy, (ii) vehicle injection, (iii) a combination of miglustat, allopregnanolone, and 2-hydroxypropyl-ß-cyclodextrin (HPßCD), (iv) miglustat, and (v) HPßCD alone starting at P7 and repeated weekly throughout life. The 12 respective male and female wild-type mice groups were evaluated in parallel. In total, 351 mice (176 Npc1+/+, 175 Npc1-/-) were dissected at P65. In both sexes, the body weights of None and Sham Npc1-/- mice were lower than those of respective Npc1+/+ mice. The influence of the Npc1 mutation and/or sex on the weights of various organs, however, differed considerably. In males, Npc1+/+ and Npc1-/- mice had comparable absolute weights of lungs, spleen, and adrenal glands. In Npc1-/- mice, smaller weights of hearts, livers, kidneys, testes, vesicular, and scent glands were found. In female Npc1-/- mice, ovaries, and uteri were significantly smaller. In Npc1-/- mice, relative organ weights, i.e., normalized with body weights, were sex-specifically altered to different extents by the different therapies. The combination of miglustat, allopregnanolone, and the sterol chelator HPßCD partly normalized the weights of more organs than miglustat or HPßCD mono-therapies.

Differential Cellular Balance of Olfactory and Vomeronasal Epithelia in a Transgenic BACHD Rat Model of Huntington's Disease.

Background. For neurodegenerative diseases such as Huntington's disease (HD), early diagnosis is essential to treat patients and delay symptoms. Impaired olfaction, as observed as an early symptom in Parkinson´s disease, may also constitute a key symptom in HD. However, there are few reports on olfactory deficits in HD. Therefore, we aimed to investigate, in a transgenic rat model of HD: (1) whether general olfactory impairment exists and (2) whether there are disease-specific dynamics of olfactory dysfunction when the vomeronasal (VNE) and main olfactory epithelium (MOE) are compared. Methods. We used male rats of transgenic line 22 (TG22) of the bacterial artificial chromosome Huntington disease model (BACHD), aged 3 days or 6 months. Cell proliferation, apoptosis and macrophage activity were examined with immunohistochemistry in the VNE and MOE. Results. No differences were observed in cellular parameters in the VNE between the groups. However, the MOE of the 6-month-old HD animals showed a significantly increased number of mature olfactory receptor neurons. Other cellular parameters were not affected. Conclusions. The results obtained in the TG22 line suggest a relative stability in the VNE, whereas the MOE seems at least temporarily affected.

PRG3 and PRG5 C-Termini: Important Players in Early Neuronal Differentiation.

The functional importance of neuronal differentiation of the transmembrane proteins' plasticity-related genes 3 (PRG3) and 5 (PRG5) has been shown. Although their sequence is closely related, they promote different morphological changes in neurons. PRG3 was shown to promote neuritogenesis in primary neurons; PRG5 contributes to spine induction in immature neurons and the regulation of spine density and morphology in mature neurons. Both exhibit intracellularly located C-termini of less than 50 amino acids. Varying C-termini suggested that these domains shape neuronal morphology differently. We generated mutant EGFP-fusion proteins in which the C-termini were either swapped between PRG3 and PRG5, deleted, or fused to another family member, plasticity-related gene 4 (PRG4), that was recently shown to be expressed in different brain regions. We subsequently analyzed the influence of overexpression in immature neurons. Our results point to a critical role of the PRG3 and PRG5 C-termini in shaping early neuronal morphology. However, the results suggest that the C-terminus alone might not be sufficient for promoting the morphological effects induced by PRG3 and PRG5.

Stimulation of mGluR1/5 Improves Defective Internalization of AMPA Receptors in NPC1 Mutant Mouse.

Niemann-Pick type C1 (NPC1) disease is characterized by neurodegeneration caused by cholesterol accumulation in the late endosome/lysosome. In this study, a defective basal and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-stimulated internalization of GluR2-containing AMPA receptors in NPC1-/- cortical neurons was detected. Our results show that the amount of cholesterol and group I metabotropic glutamate receptors (mGluR1/5) in lipid rafts of NPC1-/- cortical tissue and neurons are decreased and their downstream signals of p-ERK are defective, which are restored by a rebalance of cholesterol homeostasis through ß-cyclodextrin (ß-CD) treatment. Application of 3,5-dihydroxyphenylglycine (DHPG)-a mGluR1/5 agonist-and ß-CD markedly increases the internalization of AMPA receptors and decreases over-influx of calcium in NPC1-/- neurons, respectively. Furthermore, the defective phosphorylated GluR2 and protein kinase C signals are ameliorated by the treatment with DHPG and ß-CD, respectively, suggesting an involvement of them in internalization dysfunction. Taken together, our data imply that abnormal internalization of AMPA receptors is a critical mechanism for neuronal dysfunction and the correction of dysfunctional mGluR1/5 is a potential therapeutic strategy for NPC1 disease.

Gender-Specific Effects of Two Treatment Strategies in a Mouse Model of Niemann-Pick Disease Type C1.

In a mouse model of Niemann-Pick disease type C1 (NPC1), a combination therapy (COMBI) of miglustat (MIGLU), the neurosteroid allopregnanolone (ALLO) and the cyclic oligosaccharide 2-hydroxypropyl-ß-cyclodextrin (HPßCD) has previously resulted in, among other things, significantly improved motor function. The present study was designed to compare the therapeutic effects of the COMBI therapy with that of MIGLU or HPßCD alone on body and brain weight and the behavior of NPC1-/- mice in a larger cohort, with special reference to gender differences. A total of 117 NPC1-/- and 123 NPC1+/+ mice underwent either COMBI, MIGLU only, HPßCD only, or vehicle treatment (Sham), or received no treatment at all (None). In male and female NPC1-/- mice, all treatments led to decreased loss of body weight and, partly, brain weight. Concerning motor coordination, as revealed by the accelerod test, male NPC1-/- mice benefited from COMBI treatment, whereas female mice benefited from COMBI, MIGLU, and HPßCD treatment. As seen in the open field test, the reduced locomotor activity of male and female NPC1-/- mice was not significantly ameliorated in either treatment group. Our results suggest that in NPC1-/- mice, each drug treatment scheme had a beneficial effect on at least some of the parameters evaluated compared with Sham-treated mice. Only in COMBI-treated male and female NPC+/+ mice were drug effects seen in reduced body and brain weights. Upon COMBI treatment, the increased dosage of drugs necessary for anesthesia in Sham-treated male and female NPC1-/- mice was almost completely reduced only in the female groups.

A Rare Case of Facial Artery Branching-A Review of the Literature and a Case Report with Clinical Implications.

Background and Objectives: Vascular variations appear as morphologically distinct patterns of blood diverging from the most commonly observed vessel patterns. The facial artery is considered to be the main vessel for supplying blood to the anterior part of the face. An anatomical understanding of the facial artery, its course, its topography, and its branches is important in medical and dental practice (especially in neck and face surgery), and is also essential for radiologists to be able to interpret vascular imaging in the face following angiography of the region. A profound knowledge of the arteries in the region will aid in minimizing the risks to the patient. Materials and Methods: In our publication a narrative literature review and a case report are presented. Results: A rare case of a facial artery pattern has been described anatomically for the first time with respect to its course and branching. This variation was found on the left side of a 60-year-old male corpse during anatomical dissection. The anterior branch of the facial artery arched in the direction of the labial angle, and there divided into the inferior and superior labial arteries. At the same time, the posterior branch coursed vertically and superficially to the masseter muscle. It here gave off the premasseteric branch, and continued towards the nose, where it ran below the levator labii superioris and the levator labii superioris alaeque nasi muscles and terminated at the dorsum nasi. Conclusions: Our review of the literature and the case report add to knowledge on the facial artery with respect to its topographical anatomy and its branching and termination patterns, as well as the areas of supply. An exact knowledge of individual facial artery anatomy may play an important role in the planning of flaps or tumor excisions due to the differing vascularization and can also help to prevent artery injuries during aesthetic procedures such as filler and botulinum toxin injections.

Cor Triatriatum Sinistrum Combined with Changes in Atrial Septum and Right Atrium in a 60-Year-Old Woman.

Background and Objectives: A rare case of cor triatriatum sinistrum in combination with anomalies in the atrial septum and in the right atrium of a 60-year-old female body donor is described here. Materials and Methods: In addition to classical dissection, ultrasound and magnetic resonance imaging, computer tomography and cinematic rendering were performed. In a reference series of 59 regularly formed hearts (33 men, 26 women), we looked for features in the left and right atrium or atrial septum. In addition, we measured the atrial and ventricular wall thickness in 15 regularly formed hearts (7 men, 8 women). Results: In the case described, the left atrium was partly divided into two chambers by an intra-atrial membrane penetrated by two small openings. The 2.5 cm-high membrane originated in the upper level of the oval fossa and left an opening of about 4 cm in diameter. Apparently, the membrane did not lead to a functionally significant flow obstruction due to the broad intra-atrial communication between the proximal and distal chamber of the left atrium. In concordance with this fact, left atrial wall thickness was not elevated in the cor triatriatum sinistrum when compared with 15 regularly formed hearts. In addition, two further anomalies were found: 1. the oval fossa was deepened and arched in the direction of the left atrium; 2. the right atrium showed a membrane-like structure at its posterior and lateral walls, which began at the lower edge of the oval fossa. It probably corresponds to a strongly developed eustachian valve (valve of the inferior vena cava). Conclusions: The case described suggests that malformations in the development of the atrial septum and in the regression of the valve of the right sinus vein are involved in the pathogenesis of cor triatriatum sinistrum.

The initial engraftment of tumor cells is critical for the future growth pattern: a mathematical study based on simulations and animal experiments.

BACKGROUND: Xenograft mouse tumor models are used to study mechanisms of tumor growth and metastasis formation and to investigate the efficacy of different therapeutic interventions. After injection the engrafted cells form a local tumor nodule. Following an initial lag period of several days, the size of the tumor is measured periodically throughout the experiment using calipers. This method of determining tumor size is error prone because the measurement is two-dimensional (calipers do not measure tumor depth). Primary tumor growth can be described mathematically by suitable growth functions, the choice of which is not always obvious. Growth parameters provide information on tumor growth and are determined by applying nonlinear curve fitting. METHODS: We used self-generated synthetic data including random measurement errors to research the accuracy of parameter estimation based on caliper measured tumor data. Fit metrics were investigated to identify the most appropriate growth function for a given synthetic dataset. We studied the effects of measuring tumor size at different frequencies on the accuracy and precision of the estimated parameters. For curve fitting with fixed initial tumor volume, we varied this fixed initial volume during the fitting process to investigate the effect on the resulting estimated parameters. We determined the number of surviving engrafted tumor cells after injection using ex vivo bioluminescence imaging, to demonstrate the effect on experiments of incorrect assumptions about the initial tumor volume. RESULTS: To select a suitable growth function, measurement data from at least 15 animals should be considered. Tumor volume should be measured at least every three days to estimate accurate growth parameters. Daily measurement of the tumor volume is the most accurate way to improve long-term predictability of tumor growth. The initial tumor volume needs to have a fixed value in order to achieve meaningful results. An incorrect value for the initial tumor volume leads to large deviations in the resulting growth parameters. CONCLUSIONS: The actual number of cancer cells engrafting directly after subcutaneous injection is critical for future tumor growth and distinctly influences the parameters for tumor growth determined by curve fitting.

Identification of Brain-Specific Treatment Effects in NPC1 Disease by Focusing on Cellular and Molecular Changes of Sphingosine-1-Phosphate Metabolism.

Niemann-Pick type C1 (NPC1) is a lysosomal storage disorder, inherited as an autosomal-recessive trait. Mutations in the Npc1 gene result in malfunction of the NPC1 protein, leading to an accumulation of unesterified cholesterol and glycosphingolipids. Beside visceral symptoms like hepatosplenomegaly, severe neurological symptoms such as ataxia occur. Here, we analyzed the sphingosine-1-phosphate (S1P)/S1P receptor (S1PR) axis in different brain regions of Npc1-/- mice and evaluated specific effects of treatment with 2-hydroxypropyl-ß-cyclodextrin (HPßCD) together with the iminosugar miglustat. Using high-performance thin-layer chromatography (HPTLC), mass spectrometry, quantitative real-time PCR (qRT-PCR) and western blot analyses, we studied lipid metabolism in an NPC1 mouse model and human skin fibroblasts. Lipid analyses showed disrupted S1P metabolism in Npc1-/- mice in all brain regions, together with distinct changes in S1pr3/S1PR3 and S1pr5/S1PR5 expression. Brains of Npc1-/- mice showed only weak treatment effects. However, side effects of the treatment were observed in Npc1+/+ mice. The S1P/S1PR axis seems to be involved in NPC1 pathology, showing only weak treatment effects in mouse brain. S1pr expression appears to be affected in human fibroblasts, induced pluripotent stem cells (iPSCs)-derived neural progenitor and neuronal differentiated cells. Nevertheless, treatment-induced side effects make examination of further treatment strategies indispensable.

LPA1 , LPA2 , LPA4 , and LPA6 receptor expression during mouse brain development.

BACKGROUND: LPA is a small bioactive phospholipid that acts as an extracellular signaling molecule and is involved in cellular processes, including cell proliferation, migration, and differentiation. LPA acts by binding and activating at least six known G protein-coupled receptors: LPA1-6 . In recent years, LPA has been suggested to play an important role both in normal neuronal development and under pathological conditions in the nervous system. RESULTS: We show the expression pattern of LPA receptors during mouse brain development by using qRT-PCR, in situ hybridization, and immunocytochemistry. Only LPA 1 , LPA 2, LPA 4, and LPA 6 mRNA transcripts were detected throughout development stages from embryonic day 16 until postnatal day 30 of hippocampus, neocortex, cerebellum, and bulbus olfactorius in our experiments, while expression of LPA 3 and LPA 5 genes was below detection level. In addition to our qRT-PCR results, we also analyzed the cellular protein expression of endogenous LPA receptors, with focus on LPA1 and LPA2 within postnatal brain slices and primary neuron differentiation with and without cytoskeleton stabilization and destabilization. CONCLUSIONS: The expression of LPA receptors changes depends on the developmental stage in mouse brain and in cultured hippocampal primary neurons. Interestingly, we found that commercially available antibodies for LPA receptors are largely unspecific.

A therapy with miglustat, 2-hydroxypropyl-ß-cyclodextrin and allopregnanolone restores splenic cholesterol homeostasis in Niemann-pick disease type C1.

BACKGROUND: Niemann-Pick disease type C1 (NPC1) is an autosomal-recessive lipid-storage disorder with an estimated minimal incidence of 1/120,000 live births. Besides other neuronal and visceral symptoms, NPC1 patients develop spleen dysfunction, isolated spleno- or hepatosplenomegaly and infections. The mechanisms of splenomegaly and alterations of lipid metabolism-related genes in NPC1 disease are still poorly understood. METHODS: Here, we used an NPC1 mouse model to study a splenoprotective effect of a treatment with miglustat, 2-hydroxypropyl-ß-cyclodextrin and allopregnanolone and showed that this treatment has a positive effect on spleen morphology and lipid metabolism. RESULTS: Disease progress can be halted and blocked at the molecular level. Mutant Npc1 (Npc1-/-) mice showed increased spleen weight and increased lipid accumulation that could be avoided by our treatment. Also, FACS analyses showed that the increased number of splenic myeloid cells in Npc1-/- mice was normalized by the treatment. Treated Npc1-/- mice showed decreased numbers of cytotoxic T cells and increased numbers of T helper cells. CONCLUSIONS: In summary, the treatment promotes normal spleen morphology, stabilization of lipid homeostasis and blocking of inflammation, but alters the composition of T cell subtypes.

Current Challenges in Understanding the Cellular and Molecular Mechanisms in Niemann-Pick Disease Type C1.

Rare diseases are a heterogeneous group of very different clinical syndromes. Their most common causes are defects in the hereditary material, and they can therefore be passed on to descendants. Rare diseases become manifest in almost all organs and often have a systemic expressivity, i.e., they affect several organs simultaneously. An effective causal therapy is often not available and can only be developed when the underlying causes of the disease are understood. In this review, we focus on Niemann-Pick disease type C1 (NPC1), which is a rare lipid-storage disorder. Lipids, in particular phospholipids, are a major component of the cell membrane and play important roles in cellular functions, such as extracellular receptor signaling, intracellular second messengers and cellular pressure regulation. An excessive storage of fats, as seen in NPC1, can cause permanent damage to cells and tissues in the brain and peripheral nervous system, but also in other parts of the body. Here, we summarize the impact of NPC1 pathology on several organ systems, as revealed in experimental animal models and humans, and give an overview of current available treatment options.

Botulinum Neurotoxin-A Injected Intrastriatally into Hemiparkinsonian Rats Improves the Initiation Time for Left and Right Forelimbs in Both Forehand and Backhand Directions.

Forelimb stepping is a widely used test for the assessment of forelimb akinesia in hemiparkinsonian (hemi-PD) rats. The initiation time (IT) is considered the most sensitive parameter in the stepping test procedure. Here we propose a novel, reliable, and simple method for the measurement of IT of both forelimbs in both forehand and backhand directions in rats. Evaluating the same videos taken for quantifying adjusting steps, IT measurements were done without additional experiments. This is in contrast to the classical approach introduced by Olsson et al. (1995), in which separate experiments are necessary. We successfully applied our approach to hemi-PD rats intrastriatally treated with botulinum neurotoxin-A (BoNT-A). In naïve rats, an IT of about 0.62 s was found, and in right-sided hemi-PD rats the IT of the left forepaw increased to about 3.62 s. These hemi-PD rats showed, however, reduced ITs of the impaired left forepaws 1 month and the second time 7 months after induction of hemi-PD via the injection of 1 ng BoNT-A into the ipsilateral striatum, depending on post BoNT-A survival time. The method described offers the possibility of a precise and animal-friendly evaluation of IT in rats, including the beneficial effect of BoNT-A treatment in hemi-PD rats.

Intrastriatal administration of botulinum neurotoxin A normalizes striatal D2 R binding and reduces striatal D1 R binding in male hemiparkinsonian rats.

Cerebral administration of botulinum neurotoxin A (BoNT-A) has been shown to improve disease-specific motor behavior in a rat model of Parkinson disease (PD). Since the dopaminergic system of the basal ganglia fundamentally contributes to motor function, we investigated the impact of BoNT-A on striatal dopamine receptor expression using in vitro and in vivo imaging techniques (positron emission tomography and quantitative autoradiography, respectively). Seventeen male Wistar rats were unilaterally lesioned with 6-hydroxydopamine (6-OHDA) and assigned to two treatment groups 7 weeks later: 10 rats were treated ipsilaterally with an intrastriatal injection of 1 ng BoNT-A, while the others received vehicle (n = 7). All animals were tested for asymmetric motor behavior (apomorphine-induced rotations and forelimb usage) and for striatal expression of dopamine receptors and transporters (D1 R, D2 R, and DAT). The striatal D2 R availability was also quantified longitudinally (1.5, 3, and 5 months after intervention) in 5 animals per treatment group. The 6-OHDA lesion alone induced a unilateral PD-like phenotype and a 13% increase of striatal D2 R. BoNT-A treatment reduced the asymmetry in both apomorphine-induced rotational behavior and D2 R expression, with the latter returning to normal values 5 months after intervention. D1 R expression was significantly reduced, while DAT concentrations showed no alteration. Independent of the treatment, higher interhemispheric symmetry in raclopride binding to D2 R was generally associated with reduced forelimb akinesia. Our findings indicate that striatal BoNT-A treatment diminishes motor impairment and induces changes in D1 and D2 binding site density in the 6-OHDA rat model of PD.