Search

Objective: One of the common, but less studied deficiencies in mouse models of cerebellar disorders is impaired breeding capacity. Nevertheless, there is no extensive study in Lurcher (Grid2Lc) mice, a model of olivocerebellar degeneration. The aim of this work was to analyze a breeding capacity of these mutants., Methods: Lurcher females mated with healthy wild type males were compared with two control groups: wild type females mated with wild type males and wild type females mated with Lurcher males. The breeding capacity of Lurcher mice was analyzed using a fertility rate, mating capability and pups survival rate through three consecutive litters., Results: Lurcher dams did not show significantly reduced fertility and mating capability. Nevertheless, their breeding capacity was affected by reduced litter size, maternal infanticide and higher pup mortality during the maternal care period., Conclusion: Lurcher mice are fertile and mating capable cerebellar mutants, but their breeding capacity is reduced due to the postpartum behavioral abnormalities. With regard to hyper-reactivity of the hypothalamo-pituitary-adrenal axis followed by behavioral disinhibition during stressful events in Lurcher mutants, we hypothesize that the lower breeding capacity is associated with these endocrine and behavioral abnormalities.

Young adult heterozygous Lurcher mice constitute an excellent model for studying the role of the cerebellar cortex in motor performance-including the acquisition of new motor abilities-because of the early postnatal degeneration of almost all of their Purkinje and granular cells. Wild-type and Lurcher mice were classically conditioned for eyelid responses using a delay paradigm with or without an electrolytic lesion in the interpositus nucleus. Although the late component of electrically evoked blink reflexes was smaller in amplitude and had a longer latency in Lurcher mice than that in controls, the two groups of animals presented similar acquisition curves for eyeblink conditioning. The lesion of the interpositus nucleus affected both groups of animals equally for the generation of reflex and conditioned eyelid responses. Furthermore, we recorded the multiunitary activity at the red and interpositus nuclei during the same type of associative learning. In both nuclei, the neural firing activity lagged the beginning of the conditioned response (determined by orbicularis oculi muscle response). Although red nucleus neurons and muscle activities presented a clear functional coupling (strong correlation and low asymmetry) across conditioning, the coupling between interpositus neurons and either red nucleus neurons or muscle activities was slightly significant (weak correlation and high asymmetry). Lurcher mice presented a nonlinear coupling (high asymmetry) between red nucleus neurons and muscle activities, with an evident compensatory adjustment in the correlation of firing between interpositus and red nuclei neurons (a coupling with low asymmetry), aimed probably at compensating the absence of cerebellar cortical neurons.

Lurcher mutant mice represent a model of olivocerebellar degeneration. Postnatally, a complete loss of Purkinje cells and secondary reduction of granule cells and inferior olive neurons occurs. Cerebellar ataxia is among the symptoms of degeneration of the cerebellum. The aim of the work was to identify gait parameters which are changed in Lurcher mice due to cerebellar ataxia arising from functional cerebellar decortication, and to assess the correlation between gait parameters, walking speed and performance in rotarod test. We used the adult Lurcher mutant and wild type mice of the B6CBA strain. For gait analysis the CatWalk system was used. Motor functions were examined with the rotarod. Data analysis revealed significant differences between Lurchers and controls in many gait parameters. However, almost all parameters correlated with the walking speed and the differences disappeared after the correction to the walking speed. The question is what is the primary change in Lurchers-whether the walking speed or individual gait parameters. In the rotarod test, the Lurcher mutants revealed significantly worse results than the wild type animals. No correlation between the gait parameters and performance in the rotarod test was found.

Lurcher mutant mice represent a model of olivocerebellar degeneration. They suffer from complete loss of Purkinje cells and a reduction of granule cells and inferior olive neurons. Their wild type littermates serve as healthy controls. The aim of the work was to compare solid embryonic cerebellar graft survival within a period of 9 weeks after their transplantation in adult Lurcher mutant and wild type mice of the B6CBA strain. The solid grafts were injected through a hole in the occipital bone. Host mice were sacrificed 3, 6, or 9 weeks after the transplantation and their cerebella and brain-stems were examined histologically to assess graft presence and structure. We did not find significant differences in graft survival rates between Lurcher mutant and wild type mice. The frequency of graft presence did not differ between mice examined 3, 6, and 9 weeks after the transplantation, neither in Lurchers nor in wild type mice. The grafts were of various sizes. In some cases, only small residua of the grafts were found. Nerve fiber sprouting and cell migration from the graft to the host tissue were observed more often in wild type mice than in Lurchers when examined 6 weeks after surgery. In the period 3-9 weeks after transplantation, massive dying out of the grafts was not observed despite regressive processes in some of the grafts. The degenerative changes in the Lurcher mutant cerebellum do not have strong impact on the fate of the solid cerebellar graft., ((c) 2009 Wiley-Liss, Inc.)

Lurcher mutant mice represent a model of olivocerebellar degeneration. They are used to investigate cerebellar functions, consequences of cerebellar degeneration and methods of therapy influencing them. The aim of the work was to assess the effect of foetal cerebellar graft transplantation, repeated enforced physical activity and the combination of both these types of treatment on motor skills, spontaneous motor activity and spatial learning ability in adult B6CBA Lurcher mice. Foetal cerebellar grafts were applied into the cerebellum of Lurchers in the form of solid tissue pieces. Enforced motor activity was realised through rotarod training. Motor functions were examined using bar, ladder and rotarod tests. Spatial learning was tested in the Morris water maze. Spontaneous motor activity in the open field was observed. The presence of the graft was examined histologically. Enforced physical activity led to moderate improvement of some motor skills and to a significant amelioration of spatial learning ability in Lurchers. The transplantation of cerebellar tissue did not influence motor functions significantly but led to an improvement of spatial learning ability. Mutual advancement of the effects of both types of treatment was not observed. Spontaneous motor activity was influenced neither by physical activity nor by the transplantation. Physical activity did not influence the graft survival and development. Because nerve sprouting and cell migration from the graft to the host cerebellum was poor, the functional effects of the graft should be explained with regard to its trophic influence rather than with any involvement of the grafted cells into neural circuitries.

Some implications of cooperative potential of metal ions and electromagnetic fields' radiation (EMF) in carcinogenic processes are discussed. It is known that these factors, chemical and physical individually have connections with processes of oxidative stress. Special attention was paid to possible manifestation within the brain. Therefore, the entry of a few potentially neurotoxic metals into the brain is discussed.

Lurcher mutant mice represent a model of olivocerebellar degeneration. Due to loss of Purkinje cells, they suffer from functional cerebellar decortication resulting in ataxia and deterioration of cognitive functions. The aim of the work was to assess the effect of enforced physical activity represented by rotarod training on motor skills and spatial learning in young and adult B6CBA Lurcher mice. These functions were compared with those in untrained wild type mice of the same age. We examined motor skills using bar, ladder and rotarod tests. Spatial learning was tested in the Morris water maze. Motor skills of Lurchers were found to be worse than in wild type mice, but they showed motor learning in the course of training. The training did not significantly influence the results on the bar and ladder. In the rotarod test, young trained Lurchers achieved only slightly better results than untrained ones. In adult mice, the improvement was insignificant. Lurchers failed in spatial learning test compared to the wild type mice. In the wild type mice there was no difference in learning between young and adult individuals, while young Lurchers learned better than older ones. Enforced motor activity led to spatial learning improvement in older Lurchers, but not in young ones. The experiments showed that effects of enforced physical activity in Lurcher mice mitigated the deficit in the water maze task related to age so that trained older Lurchers showed as good performance as younger ones but still worse than the wild type mice.

Microscopical examination of brain tissue appears as a valuable process, which can acknowledge, complete or confute the acquired findings by functional experiments. The purpose of this work was to survey histo-morphological and functio-morphological techniques mostly used in the neuropathophysiological research with application examples. The most common pathological processes in the brain is possible to document with some of this methods. Whether there are developmental, traumatical, degenerative, on the base of ischemia, reperfusion developed or only functional changes. The work deals with methods histological-non-specific, that offer comprehensive image- as hematoxiline-eosine staining, Nissl staining, Golgi impregnation. Further with cyto- and histochemical techniques- as Fluoro-Jade staining and NADPH-diaphorase detection and with immunohistochemical methods, in which marking with anticalbindin and imaging of c-fos protein are noted.

Adult heterozygous Lurcher mice show a degeneration of almost all Purkinje cells and 90% of the granular cells of the cerebellum, resulting in ataxia or general deficits in motor coordination. These mice are therefore an excellent model for studying the role of the cerebellar cortex in motor performance, including the acquisition of new motor abilities. The performance of 3-month-old Lurcher mice was studied in various behavioural (fall, horizontal bar, rotating cylinder, and ladder), spatial orientation (water maze) and associative learning (eyelid classical conditioning) tasks and compared with that of wild-type mice. Behavioural tasks indicated a deficit for motor abilities in Lurcher mice but with some adaptation to the tests and improvement in performance. Wild-type and Lurcher mice performed swimming equally, but the latter learned the task significantly more slowly than the former. The late component of reflex blinks was smaller in amplitude and had a longer latency in Lurcher mice than in controls. Learning curves for Lurcher mice during classical conditioning of eyelid responses were similar to controls, but the amplitude of the learned response in Lurcher mice was significantly lower. The startle response to a severe tone was similar in both control and Lurcher mice but the latter were unable to produce prepulse inhibition. These results suggest that the cerebellar cortex is not indispensable for the performance of this complete set of skeletal and facial tasks, or for the acquisition of new motor abilities, but it is for the appropriate execution and adjustment of any of these motor activities.

The development of motor learning and topical motor skills has been studied during the first month of life in neurodeficient Lurcher mutant mice derived from C3H strain. The examination of motor functions was conducted using four methods when animals were consecutively placed on: a horizontal wire, a rotating cylinder, a bridge and slanting ladder (on the rotating cylinder and slanting ladder in three different starting positions). A total of 150 animals were used, half being heterozygous mutants (+/Lc), the remaining consisting of their healthy littermates, homozygous wild-type mice (+/+). Some animals of both types were confronted with the tasks in four testing days without practice while the others were trained in all of these methods one time daily at the age of 3, 6, 9, 12, 15, 20, 25 and 30 days. The results of the research are expressed as a percentage of reaching criteria in the trained and untrained mice of both types (+/Lc, +/+), respectively on days 15, 20, 25, and 30. Because of their motor handicap, Lurcher mutants showed significantly worse results than normal mice in almost all of the tests. The most interesting observations of the study were obtained on the rotating cylinder and the slanting ladder tests where mainly untrained mutants were unable to cope promptly with the different starting position and failed. However, in 30-day-old Lurchers the effect of learning was relatively better in some tests when compared with the wild-type of mice. Experiments showed that, in spite of progressive cerebellar degeneration, the ability of motor learning in Lurcher mutants survived to a certain degree. The worsening of results after frequent training in both trained Lurchers and normal mice aged 20 days as compared with untrained ones is discussed within the context of the "overtraining reversal effect" and other possible hypotheses.