Bladder dysfunction in experimental autoimmune encephalomyelitis reflects clinical severity: A pilot study.

Multiple sclerosis (MS) is commonly associated with bladder dysfunction resulting in a progressive loss of voluntary control for urination over time. Here, we used the voided stain on paper (VSOP) method to investigate bladder function in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS. Using the VSOP test, we show that bladder dysfunction reflects pro-inflammatory processes of EAE and severity of clinical EAE symptoms, as characterized by increased urine voided volume per micturition (UVVM) on post-induction day 7 and decreased UVVM on post-induction day 14. The UVVM was closely related to a clinical disease index of EAE symptoms and plasma granulocyte-macrophage colony-stimulating factor (GM-CSF) cytokine levels. UVVM was also sensitive to early life stress caused by animal transportation, which diminished UVVM at the peak of symptoms on post-induction day 14 in EAE mice. The results indicate that symptoms and progression of EAE can be reliably measured by VSOP as a non-motor function assessment.

Activation of BDNF- and VEGF-mediated Neuroprotection by Treadmill Exercise Training in Experimental Stroke.

Early treatment of ischemic stroke is one of the most effective ways to reduce brains' cell death and promote functional recovery. This study was designed to examine the effect of aerobic exercise on post ischemia/reperfusion injury on concentration and expression of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) after inducing a neuronal loss in CA1 region of hippocampus in Male Wistar rats. Three experimental groups including sham(S), ischemia/reperfusion-control (IRC) and ischemia/reperfusion exercise (IRE) were used for this purpose. The rats in the IRE group received a bilateral carotid artery occlusion treatment. They ran for 45 minutes on a treadmill five days per week for eight consecutive weeks. Cresyl violet (Nissl), Hematoxylin (H & E) and Eosin staining procedure were used to determine the extent of damage. A ladder rung walking task was used to assess the functional impairments and recovery after the ischemic lesion. ELISA and immunohistochemistry method were employed to measure BDNF and VEGF protein expressions. The result showed that the brain ischemia/reperfusion condition increased the cell death in hippocampal CA1 neurons and impaired motor performance on the ladder rung task whereas the aerobic exercise program significantly decreased the brain cell's death and improved motor skill performance. It was concluded that ischemic brain lesion decreased the BDNF and VEGF expression. It seems that the aerobic exercise following the ischemia/reperfusion potentially promotes neuroprotective mechanisms and neuronal repair and survival mediated partly by BDNF and other pathways.

Ancestral stress programs sex-specific biological aging trajectories and non-communicable disease risk.

The incidence of non-communicable diseases (NCDs) is rising globally but their causes are generally not understood. Here we show that cumulative ancestral stress leads to premature aging and raises NCD risk in a rat population. This longitudinal study revealed that cumulative multigenerational prenatal stress (MPS) across four generations (F0-F3) raises age- and sex-dependent adverse health outcomes in F4 offspring. MPS accelerated biological aging processes and exacerbated sex-specific incidences of respiratory and kidney diseases, inflammatory processes and tumors. Unbiased deep sequencing of frontal cortex revealed that MPS altered expression of microRNAs and their target genes involved in synaptic plasticity, stress regulation, immune function and longevity. Multi-layer top-down deep learning metabolite enrichment analysis of urine markers revealed altered metabolic homeodynamics in MPS males. Thus, peripheral metabolic signatures may provide sensitive biomarkers of stress vulnerability and disease risk. Programming by MPS appears to be a significant determinant of lifetime mental health trajectories, physical wellbeing and vulnerability to NCDs through altered epigenetic regulation.

The crucial role of DNA-dependent protein kinase and myelin transcription factor 1-like protein in the miR-141 tumor suppressor network.

Glioblastoma is the most aggressive brain tumor. Although miR-141 has been demonstrated to primarily function as a tumor suppressor in numerous malignancies, including glioblastoma, the mechanisms involved remain poorly understood. Here, it is shown that miR-141 is downregulated in glioblastoma cell lines and tissues and may exert its biological function via directly targeting myelin transcription factor 1-like (MYT1L). Using two glioblastoma cell lines that differ from each other by the functionality of DNA-dependent protein kinase (DNAPK), a functional involvement of DNAPK in the miR-141 tumor suppression network was observed. In M059K cells with a normal function of DNAPK, the enforced expression of miR-141 attenuated MYT1L expression and suppressed cell proliferation. Conversely, the inhibition of miR-141 expression promoted cell proliferation; however, in M059J cells with a loss-of-function DNAPK, miR-141 constitutively inhibited cell proliferation upon ectopic overexpression or inhibition. An overexpression of miR-141 suppressed M059J cell migration, while it had no effect on M059K. Furthermore, the ectopic expression of miR-141 induced an S-phase arrest in both cell lines, whereas the inhibition of miR-141 caused a G1 arrest in M059J and accelerated the S phase in M059K. An overexpression and suppression of miR-141 resulted in an aberrant expression of cell-cycle proteins, including p21. Moreover, MYT1L may be a transcription factor of p21 in p53-mutant cells, whereas DNAPK may function as a repressor of MYT1L. The findings revealed the crucial role of DNAPK in miR-141-mediated suppression of gliomagenesis and demonstrated that it may be a target molecule in miR-141-associated therapeutic interventions for glioblastoma.

Exogenous adenosine facilitates neuroprotection and functional recovery following cerebral ischemia in rats.

INTRODUCTION & OBJECTIVE: Cerebral ischemia causes physiological and biochemical cellular changes that ultimately result in structural and functional damage to hippocampal neurons. Ischemia also raises endogenous adenosine release that in turn has neuroprotective effects. The purpose of this study was to evaluate the effect of exogenous adenosine on mitigating neuronal lesions to the CA1 region of hippocampus and A2A protein expression following cerebral I/R in rats. METHODS: Male Wistar rats were randomly assigned to three experimental groups (sham, ischemia + control, and ischemia + adenosine). A daily dose of adenosine (0.1 mg/ml/kg, i.p.) was administered starting 24 h post-ischemia for 7 days. Ischemia was induced by occlusion of both common carotid arteries for 45 min. Cresyl violet and Hematoxylin Eosin staining were used to assess lesion extent and location. To investigate the expression and protein levels, immunohistochemistry and enzyme-linked immunosorbent assay method was used. RESULTS: The cerebral ischemia caused neuronal loss in the CA1 region and reduced sensorimotor functions in lesion animals. Injection of adenosine significantly diminished cell death and improved sensorimotor functional recovery. Moreover, the expression and concentration of A2A protein was significantly greater in the adenosine group compared to the ischemia group. CONCLUSION: This study showed that the administration of exogenous adenosine promotes protection against cell death and supports functional recovery following ischemic injury.

Adverse effects of paternal chemotherapy exposure on the progeny brain: intergenerational chemobrain.

Recent advances in cancer treatments have led to significant increases in cure rates. Most cancer patients are treated with various cytotoxic chemotherapy regimens. These treatment modalities are mutagenic and genotoxic and cause a wide array of late-occurring health problems, and even exert a deleterious influence on future offspring. The adverse effects from exposed parents on offspring are referred to as transgenerational effects, and currently little is known about chemotherapy-induced transgenerational effects. Furthermore, transgenerational effects have not been studied in the brains of progeny of exposed parents. In this study, we analyzed the existence and molecular nature of transgenerational effects in the brains of progeny of animals exposed to three common chemotherapy agents: cyclophosphamide (CPP), procarbazine (PCB) and mitomycin C (MMC). For the first time, our results show that paternal exposure to chemotherapy drugs causes transgenerational changes in the brain of unexposed progeny. Although no DNA damage was observed in terms of γH2AX levels, some alterations were found in levels of PCNA, protein involved in DNA repair, replication and profileration. Furthermore, there were changes in proliferation and apoptosis proteins BCL2 and AKT1, the proteins associated with DNA methylation, DNMT1 and MeCP2. Some altered expression trends were noted in proteins involved in myelin biogenesis, MBP and MYT1L. Moreover, global transcriptome profiling revealed changes in over 200 genes in the whole brains of progeny of animals exposed to CPP, and the changes in the levels of FOXP2 and ELK1proteins were confirmed by western blot analysis. These findings suggest that paternal chemotherapy significantly affects offspring brain development and may affect brain functioning. This research provides a key roadmap for future investigations of the novel phenomenon of transgenerational effects of chemotherapy in the brain of progeny of exposed parents.

Organization of the reach and grasp in head-fixed vs freely-moving mice provides support for multiple motor channel theory of neocortical organization.

Multiple motor channel (MMC) theory of neocortical organization proposes that complex movements, such as reaching for a food item to eat, are produced by the coordinated action of separate neural channels. For example, the human reach-to-grasp act is mediated by two visuo-parieto-motor cortex channels, one for the reach and one for the grasp. The present analysis asked whether there is a similar organization of reach-and-grasp movements in the mouse. The reach-to-eat movements of the same mice were examined from high-shutter speed, frame-by-frame video analysis in three tasks in which the mice obtained equivalent success scores: when freely-moving reaching for food pellets, when head-fixed reaching for food pellets, and when head-fixed reaching for pieces of pasta. To reach, the mice used egocentric cues to vary upper arm movements in a task-appropriate manner to place an open hand on the food or to locate the food using a "touch-release-grasp" strategy. Although mice could not hand-shape offline when reaching, they could hand-shape using online touch-related cues from the mouth to manipulate the food at the mouth. That the reach can be performed offline in relation to egocentric cues whereas hand shaping for the grasp requires online cues supports the idea that for the mouse, as for primates, the reach and grasp are separate acts. The results are further discussed in relation to the use of the head-fixed behavioral procedure to identify the independent neural substrates of the reach and the grasp using mesoscale stimulation/imaging methods.

Fractionated low-dose exposure to ionizing radiation leads to DNA damage, epigenetic dysregulation, and behavioral impairment.

Studies of Fractionated Exposure to Low Doses of Ionizing Radiation (FELDIR) has become of increasing importance to clinical interventions. Its consequences on DNA damage, physical, and mental health have been insufficiently investigated, however. The goal of this study was to determine the effects of FELDIR on the brain using a mouse model. We addressed the levels of DNA damage, global genomic methylation, and DNA methylation machinery in cerebellum, frontal lobe, olfactory bulb and hippocampal tissues, as well as behavioral changes linked to FELDIR exposure. The results reveal increased levels of DNA damage, as reflected by increased occurrence of DNA Strand Breaks (SBs) and dysregulation of stress-response kinase p38. FELDIR also resulted in initial loss of global genomic methylation and altered expression of methyltransferases DNMT1 (down-regulation) and DNMT3a (up-regulation), as well as methyl-binding protein MeCP2 (up-regulation). FELDIR-associated behavioral changes included impaired skilled limb placement on a ladder rung task, increased rearing activity in an open field, and elevated anxiety-like behaviors. The said alterations showed significant dose and tissue specificity. Thus, FELDIR represents a critical impact on DNA integrity and behavioral outcomes that need to be considered in the design of clinical intervention studies.

Topographical disorientation after ischemic mini infarct in the dorsal hippocampus: whispers in silence.

Silent focal ischemic mini infarcts in the brain are thought to cause no clinically overt symptoms. Some populations of hippocampal cells are particularly sensitive to ischemic events, however, rendering hippocampal functions especially vulnerable to ischemia-induced deficits. The present study investigated whether an otherwise silent ischemic mini infarct in the hippocampus (HPC) can produce impairments in spatial performance in rats. Spatial performance was assessed in the ziggurat task (ZT) using a 10-trial spatial learning protocol for 4 days prior to undergoing hippocampal ischemic lesion or sham surgery. Hippocampal silent ischemia was induced by infusion of endothelin-1 (ET-1), a potent vasoconstrictor, into either the dorsal or the ventral hippocampus (dHPC and vHPC). When tested postoperatively in the ZT using a standard testing protocol for 8 days, rats with hippocampal lesions exhibited no spatial deficit. Although spatial learning and memory in the ZT were not affected by the ET-1-induced silent ischemia, rats with dHPC stroke showed more returns when navigating the ZT as opposed to the vHPC rats. Comparison of region-specific HPC lesions in the present study indicated that dorsal hippocampal function is critically required for topographic orientation in a complex environment. Topographic disorientation as reflected by enhanced return behaviors may represent one of the earliest predictors of cognitive decline after silent ischemic insult that may be potentially traced with sensitive clinical examination in humans.

Immunosenescence is associated with altered gene expression and epigenetic regulation in primary and secondary immune organs.

Deterioration of the immune system (immunosenescence) with age is associated with an increased susceptibility to infection, autoimmune disease and cancer, and reduced responsiveness to vaccination. Immunosenescence entails a reduced supply of naïve T cells from the thymus and increased specialization of peripheral T cell clones. Both thymic involution and peripheral T cell homeostasis are thought to involve cellular senescence. In order to analyze this at the molecular level, we studied gene expression profiles, epigenetic status, and genome stability in the thymus and spleen of 1-, 4-, and 18-month-old Long Evans rats. In the thymus, altered gene expression, DNA and histone H3K9 hypomethylation, increased genome instability, and apoptosis were observed in 18-month-old animals compared to 1- and 4-month-old animals. In the spleen, alterations in gene expression and epigenetic regulation occurred already by the age of 4 months compared to 1 month and persisted in 18-month-old compared to 1-month-old rats. In both organs, these changes were accompanied by the altered composition of resident T cell populations. Our study suggests that both senescence and apoptosis may be involved in altered organ function.

Hair trace elementary profiles in aging rodents and primates: links to altered cell homeodynamics and disease.

Aging is associated with an increased incidence of pathological conditions such as neurodegeneration, cardiovascular and renal disease, and cancer. These conditions are believed to be linked to a disruption in cell homeodynamics, which is regulated by essential trace elements. In this study we used hair elementary analysis by inductively coupled plasma mass spectrometry (ICPMS) to examine age-related profiles of 47 elements in both rats and common marmoset monkeys. Hair was collected from young adult (6 months) and aged (18 months) Long-Evans male rats, and young adult (2 years), middle-aged (4 years) and aged (>8 years) marmosets. The results revealed that aging reduces content levels of cobalt, potassium and selenium while content levels of aluminium, arsenic, boron, mercury, molybdenum, and titanium were elevated in aged rats. Similarly, aged marmosets showed reduced levels of cobalt and elevated levels of aluminium. Case studies in aged rats revealed that myocardial infarction was associated with elevated levels of sodium, potassium and cadmium and reduced zinc, while renal failure was linked to elevated content of potassium, chloride and boron and reduced contents of manganese. Carcinoma was linked to elevated arsenic and reduced selenium levels. These findings indicate that hair elementary profiles in healthy aging and age-related diseases reflect altered cell and organ metabolic functions. Cobalt and aluminium in particular may serve as biomarkers of aging in animal models. Thus, elementary deposition in hair may have predictive and diagnostic value in age-related pathological conditions, including cardiovascular and kidney disease and cancer.

Maternal circulating leukocytes display early chemotactic responsiveness during late gestation.

BACKGROUND: Parturition has been widely described as an immunological response; however, it is unknown how this is triggered. We hypothesized that an early event in parturition is an increased responsiveness of peripheral leukocytes to chemotactic stimuli expressed by reproductive tissues, and this precedes expression of tissue chemotactic activity, uterine activation and the systemic progesterone/estradiol shift. METHODS: Tissues and blood were collected from pregnant Long-Evans rats on gestational days (GD) 17, 20 and 22 (term gestation). We employed a validated Boyden chamber assay, flow cytometry, quantitative real time-polymerase chain reaction, and enzyme-linked immunosorbent assays. RESULTS: We found that GD20 maternal peripheral leukocytes migrated more than those from GD17 when these were tested with GD22 uterus and cervix extracts. Leukocytes on GD20 also displayed a significant increase in chemokine (C-C motif) ligand 2 (Ccl2) gene expression and this correlated with an increase in peripheral granulocyte proportions and a decrease in B cell and monocyte proportions. Tissue chemotactic activity and specific chemokines (CCL2, chemokine (C-X-C motif) ligand 1/CXCL1, and CXCL10) were mostly unchanged from GD17 to GD20 and increased only on GD22. CXCL10 peaked on GD20 in cervical tissues. As expected, prostaglandin F2α receptor and oxytocin receptor gene expression increased dramatically between GD20 and 22. Progesterone concentrations fell and estradiol-17ß concentrations increased in peripheral serum, cervical and uterine tissue extracts between GD20 and 22. CONCLUSION: Maternal circulating leukocytes display early chemotactic responsiveness, which leads to their infiltration into the uterus where they may participate in the process of parturition.

Identification of bilateral changes in TID1 expression in the 6-OHDA rat model of Parkinson's disease.

Parkinson's disease (PD) is a common neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra and the aggregation of α-synuclein into Lewy bodies. Existing therapies address motor dysfunction but do not halt progression of the disease. A still unresolved question is the biochemical pathway that modulates the outcome of protein misfolding and aggregation processes in PD. The molecular chaperone network plays an important defensive role against cellular protein misfolding and has been identified as protective in experimental models of protein misfolding diseases like PD. Molecular mechanisms underlying chaperone-neuroprotection are actively under investigation. Current evidence implicates a number of molecular chaperones in PD including Hsp25, Hsp70 and Hsp90, however their precise involvement in the neurodegenerative cascade is unresolved. The J protein family (DnaJ or Hsp40 protein family) has long been known to be important in protein conformational processes.We assessed sensory and motor function of control and PD rats and then evaluated the brain region-specific expression levels of select J proteins by Western analysis. Surprisingly, we observed a widespread 26 kDa breakdown product of the J protein, TID1, (tumorous imaginal discs, mtHsp40 or DnaJ3) in a 6-hydroxydopamine (6-OHDA) rat model of PD in which food handling, gait symmetry and sensory performance were impaired. Greater behavioral deficits were associated with lower TID1 expression. Furthermore, direct application of either 6-OHDA or MPP+ (1-methyl-4-phenylpyridinum) to CAD (CNS-derived catecholinaminergic neuronal cell line) cell cultures, reduced TID1 expression levels.Our results suggest that changes in cellular TID1 are a factor in the pathogenesis of PD by impeding functional and structural compensation and exaggerating neurodegenerative processes. In contrast, no changes were observed in CSPα, Hsp40, Hsp70, Hsc70 and PrP(C) levels and no activation of caspase3 was observed. This study links TID1 to PD and provides a new target for therapeutics that halts the PD progression.

Walking pattern analysis after unilateral 6-OHDA lesion and transplantation of foetal dopaminergic progenitor cells in rats.

Functional sensorimotor recovery after transplantation of mesencephalic dopaminergic (DAergic) neurons has been well documented in the rat 6-hydroxydopamine (6-OHDA) model of Parkinson's disease. However, the functional restoration of more specific gait-related patterns such as skilled walking, balance, and individual limb movements have been insufficiently studied. The purpose of this study was to investigate the behavioural effects of intrastriatal DA grafts on different aspects of normal and skilled walking in rats following unilateral 6-OHDA lesions of the medial forebrain bundle. Rats were subjected to drug-induced rotation, detailed footprint analysis, and assessment of skilled walking in the ladder rung walking test prior and after the transplantation of E14 ventral mesencephalon-derived progenitor cells. Good DAergic graft survival, as revealed by immunohistochemistry, was accompanied by a compensation of drug-induced rotational asymmetries. Interestingly, the analysis of walking patterns displayed a heterogeneous graft-induced response in skilled and non-skilled limb use. Grafted animals made fewer errors with their contralateral limbs in skilled walking than the sham-transplanted rats, and they improved their ipsi- and contralateral limb rotation. However, the parameter distance between feet showed a delayed recovery, and the stride length was not affected by the DA grafts at all. These findings indicate that ectopic intrastriatal transplantation of E14 ventral mesencephalon-derived cells promotes recovery of gait balance and stability, but does not ameliorate the shuffling gait pattern associated with 6-OHDA lesions. A full restoration of locomotor gait pattern might require a more complete and organotypic reconstruction of the mesotelencephalic DAergic pathway.

Sex differences in skilled movement in response to restraint stress and recovery from stress.

Sex differences exist in skilled movement, and skilled motor performance is also influenced by stress. As shown for cognitive function, the effects of stress are usually characterized by considerable sexual dimorphism. The purpose of this study was to investigate sex differences in skilled motor function in response to stress. Male and female Long-Evans rats were trained and tested in skilled reaching and skilled walking tasks. Both groups of animals were then exposed to daily restraint stress for 15 days. Recovery from daily stress was assessed by comparing reaching performance at 10 min versus 60 min after restraint stress, and recovery from chronic stress was tested for 21 days after cessation of stress. Animals were tested daily in skilled reaching for the entire period. Observations showed that females performed significantly better than males during the stress period in terms of reaching success and number of attempts needed to grasp a food pellet. No difference between testing at 10 or 60 min after daily stress was found. Analysis of movement patterns and recovery from stress indicated that males and females use different strategies to overcome stress-induced motor disturbance. While male rats preferred to use original movement patterns, females tended to modify these patterns in order to increase reaching success. Modification of movement patterns in female rats was accompanied by a faster recovery in success rate after the cessation of stress. These results indicate sex differences in skilled reaching in response to stress, and in the recovery period after stress.

Use of rotorod as a method for the qualitative analysis of walking in rat.

High speed video analysis of the details of movement can provide a source of information about qualitative aspects of walking movements. When walking on a rotorod, animals remain in approximately the same place making repetitive movements of stepping. Thus the task provides a rich source of information on the details of foot stepping movements. Subjects were hemi-Parkinson analogue rats, produced by injection of 6-hydroxydopamine (6-OHDA) into the right nigrostriatal bundle to deplete nigrostriatal dopamine (DA). The present report provides a video analysis illustration of animals previously were filmed from frontal, lateral, and posterior views as they walked (15). Rating scales and frame-by-frame replay of the video records of stepping behavior indicated that the hemi-Parkinson rats were chronically impaired in posture and limb use contralateral to the DA-depletion. The contralateral limbs participated less in initiating and sustaining propulsion than the ipsilateral limbs.These deficits secondary to unilateral DA-depletion show that the rotorod provides a use task for the analysis of stepping movements.A more detailed presentation of the present study has been made (Whishaw et al, 2003), but the present study presents the video support describing the stepping movement in the good and affected limbs of unilateral dopamine-depleted rats. For the analysis, rats with unilateral DA depletions and control rats were video recorded from front, lateral and posterior views. A rating scale of posture and forelimb movements indicated that stepping movements were chronically impaired following surgery. Examination of limb movements indicated that whereas the DA-depleted rats could use the limbs contralateral to the lesion for support, they received minimal use for shifting weight. The results of this study indicate that the rotorod task, in addition to providing quantitative measures of motor impairments, can also provide insights into the qualitative impairments [corrected].

Dietary restriction alters fine motor function in rats.

A number of standard behavioral tasks in animal research utilize food rewards for positive reinforcement. In order to enhance the motivation to participate in these tasks, animals are usually placed on a restricted diet. While dietary restriction (DR) has been shown to have beneficial effects on recovery after brain injury, life span and aging processes, it might also represent a stressor. Since stress can influence a broad range of behaviors, the purpose of this study was to assess whether DR may have similar effects on skilled movement. Adult male Long-Evans rats were trained and tested in a skilled reaching task both prior to and during a mild food restriction regimen that maintained their body weights at 90-95% of baseline weight for eight days. The observations revealed that DR decreased reaching success and increased the number of attempts to grasp a single food pellet. The animals appeared to be more frantic when attempting to reach for food pellets, and the time taken to reach for 20 pellets decreased following the onset of DR. A second experiment investigating behaviors that do not require food rewards, including a ladder rung walking task and an open field test, confirmed that rats on DR display deficits in skilled movements and are hyperactive. These findings suggest that results obtained in motor tasks using food rewards need to be interpreted with caution. The findings are discussed with respect to stress associated with DR.

Distinct forelimb and hind limb stepping impairments in unilateral dopamine-depleted rats: use of the rotorod as a method for the qualitative analysis of skilled walking.

The rotorod test, in which animals walk on a rotating drum, is widely used to assess motor status in laboratory rodents. Performance is measured by the duration that an animal stays up on the drum as a function of drum speed. Here we report that the task provides a rich source of information about qualitative aspects of walking movements. Because movements are performed in a fixed location, they can readily be examined using high-speed video recording methods. The present study was undertaken to examine the potential of the rotorod to reveal qualitative changes in the walking movements of hemi-Parkinson analogue rats, produced by injection of 6-hydroxydopamine (6-OHDA) into the nigrostriatal bundle to deplete nigrostriatal dopamine (DA). Beginning on the day following surgery and then periodically over the next two months, the rats were filmed from frontal, lateral, and posterior views as they walked on the rotorod. Behavior was analyzed by frame-by-frame replay of the video records. Rating scales of stepping behavior indicated that the hemi-Parkinson rats were chronically impaired in their posture and in the use of the limbs contralateral to the DA-depletion. The contralateral limbs not only displayed postural and movement abnormalities, they participated less in initiating and sustaining propulsion than did the ipsilateral limbs. These findings not only reveal new deficits secondary to unilateral DA-depletion, but also show that the rotorod can provide a robust tool for the qualitative analysis of movement.