Lurcher Mutant Research Articles

Differences between the GluD1 and GluD2 receptors revealed by GluD1 X-ray crystallography, binding studies and molecular dynamics.

Ionotropic glutamate receptors are ligand-gated ion channels essential for fast excitatory neurotransmission in the brain. In contrast to most other members of the iGluR family, the subfamily of delta receptors, GluD1 and GluD2, does not bind glutamate but glycine/D-serine. GluD1 is widely expressed in the brain and the inner ear, where it is required for high-frequency hearing. Furthermore, it has been associated with schizophrenia, autism and depression. X-ray structures of the ligand-binding domain (LBD) of GluD2 have been published; however, no high-resolution structure is available for the ligand-binding domain of GluD1 (GluD1-LBD). Here, we report the X-ray crystal structure of the GluD1-LBD in its apo form at 2.57 Å resolution. Using isothermal titration calorimetry, we show that D-serine binds to the GluD1-LBD in an exothermic manner with a Kd of 160 μm, which is approximately five-fold greater than at GluD2. Furthermore, we identify Glu822 as a critical determinant of receptor activation in GluD1 A654T. In contrast to studies on the GluD2 lurcher mutant A654T, we did not observe any effect of 1 mm D-serine on the spontaneous currents at mouse GluD1 A654T by electrophysiological recordings of Xenopus laevis oocytes as previously also reported by others. These results point towards differences in the structure and dynamics between GluD1 and GluD2. Molecular dynamics simulations were employed to address this observation, suggesting that the apo structure of GluD1 is less flexible than the apo structure of GluD2 and that Pro725 in GluD1 may affect the interlobe closure of the ligand-binding domain of GluD1.

Probing the ionotropic activity of glutamate GluD2 receptor in HEK cells with genetically-engineered photopharmacology.

Glutamate delta (GluD) receptors belong to the ionotropic glutamate receptor family, yet they don't bind glutamate and are considered orphan. Progress in defining the ion channel function of GluDs in neurons has been hindered by a lack of pharmacological tools. Here, we used a chemo-genetic approach to engineer specific and photo-reversible pharmacology in GluD2 receptor. We incorporated a cysteine mutation in the cavity located above the putative ion channel pore, for site-specific conjugation with a photoswitchable pore blocker. In the constitutively open GluD2 Lurcher mutant, current could be rapidly and reversibly decreased with light. We then transposed the cysteine mutation to the native receptor, to demonstrate with high pharmacological specificity that metabotropic glutamate receptor signaling triggers opening of GluD2. Our results assess the functional relevance of GluD2 ion channel and introduce an optogenetic tool that will provide a novel and powerful means for probing GluD2 ionotropic contribution to neuronal physiology.

Familiarization effects on the behavioral disinhibition of the cerebellar Lurcher mutant mice: use of the innovative Dual Maze

Anxiety-related behaviors in mice are often assessed over short periods starting immediately after introducing the animals in a dedicated apparatus. In these usual conditions (5−10 min periods), the cerebellar Lurcher mutants showed disinhibited behaviors characterized by abnormally high exploration of the aversive areas in the elevated plus-maze test. We nevertheless observed that this disinhibition sharply weakened after 10 min. We therefore decided to further investigate the influence of the disinhibition on the intrinsic and anxiety-related exploratory behaviors in Lurcher mice, with a special focus on familiarization effects. To this end, we used an innovative apparatus, the Dual Maze, permitting to tune the familiarization level of animals to the experimental context before they are faced with more (open configuration of the device) or less (closed configuration of the device) aversive areas. Chlordiazepoxide administration in BALB/c mice in a preliminary experiment confirmed both the face and the predictive validity of our device as anxiety test and its ability to measure exploratory motivation. The results obtained with the Lurcher mice in the open configuration revealed that 20 min of familiarization to the experimental context abolished the behavioral abnormalities they exhibited when not familiarized with it. In addition, their exploratory motivation, as measured in the closed configuration, was comparable to that of their non-mutant littermates, whatever the level of familiarization applied. Exemplifying the interest of this innovative device, the results we obtained in the Lurcher mutants permitted to differentiate between the roles played by the cerebellum in exploratory motivation and stress-related behaviors.

Abnormalities in the cerebellar levels of trophic factors BDNF and GDNF in pcd and lurcher cerebellar mutant mice

Hereditary cerebellar degenerations are severe and complex diseases for which there is currently no effective causal treatment. A hopeful method could be the support of plasticity or neurotransplantation. However, there are still many unknown aspects which could influence the outcome of treatment. As neurotrophic factors are essential in neuroplasticity and neuronal integration, potential abnormalities in their levels could be involved in the pathogenesis of the disease and would possibly explain the unsuitability of diseased cerebellum for the graft integration. The aim of this study was to identify and compare basal levels of trophic factors BDNF and GDNF in the cerebellum in two mouse models of cerebellar degeneration – Lurcher and pcd. Basal levels of BDNF in the cerebellum have been shown to be lower in both mutant models than in healthy controls. However, the GDNF levels were surprisingly increased in the cerebella of Lurcher mutant mice compared to both wild type and pcd mice. In addition, a different distribution of GFAP-positive cells in the cerebellum was revealed in Lurcher mice. These differences suggest that the niche of the Lurcher mutant cerebellum is changed. The question, however, remains how these changes are related to the neurodegenerative process and how they could influence potential compensatory mechanisms, plasticity and response to therapeutic interventions.

Cerebellar degeneration averts blindness-induced despaired behavior during spatial task in mice

Lurcher mutant mice of the C3H strain provide a model of both cerebellar and retinal degeneration. Therefore, they enable the study of the behavior of cerebellar mutants under disabled visual orientation conditions. We aimed to examine cerebellar Lurcher mutants and wild type mice with intact cerebella with and without retinal degeneration employing the rotarod and Morris water maze tests. The positions of the hidden platform and the starting point in the water maze test were stable so as to enable the use of both idiothetic navigation and visual inputs. The Lurcher mice evinced approximately 90 % shorter fall latencies on the rotarod than did the wild type mice. Retinal degeneration exerted no impact on motor performance. Only the wild type mice with normal retina were able to find the water maze platform efficiently. The wild type mice with retinal degeneration developed immobility (almost 25 % of the time) as a sign of behavioral despair. The Lurchers maintained high swimming activity as a potential manifestation of stress-induced behavioral disinhibition and their spatial performance was related to motor skills and swim speed. We demonstrated that both motor deficit and pathological behavior have the potential to contribute to abnormal performance in spatial tasks. Thus, spatial disability in cerebellar mutants is most likely a complex consequence of multiple disturbances related to cerebellar dysfunction.

Twenty years of cerebellar degeneration research at the department of pathological physiology, faculty of medicine, Pilsen, Charles University.

Mutant Lurcher mice represent an animal model of naturally occurring cerebellar degeneration. A gene mutation causes the demise of all Purkinje cells, as along with certain other types, as well as the functional elimination of the cerebellar cortex. Involvement in the research using this model of the C3H strain began at the Department of Physiology, UCL in 1995/96. It continued in scientific cooperation with other European laboratories where we obtained Lurcher mice of the B6CBA strain. The aim of the effort was first to identify the extent to which the cerebellum is involved in the higher nervous activity, i.e. cognitive and other functions. In that research, use was made of an entire array of methodological procedures to examine learning, memory, motor functions and emotional behavior. It was completed with an electrophysiological examination of the brain and special microscopic procedures. The results demonstrated that the cerebellum (aside from its traditional tasks) does in fact play a significant role in cognitive function, emotions, etc. It was further found that the neurodegenerative processes also affected the immune and endocrine functions, confirming the concept of the unity of the psycho-neuroendocrine-immune system. Surprisingly, despite their neurological impairment, the affected animals were able to learn to some extent and, make progress with physical training, improving not only their motor skills but also learning and memory, including deferring of signs of aging. These particular findings may prove useful for human medicine.

Long-Term Development of Embryonic Cerebellar Grafts in Two Strains of Lurcher Mice.

For many degenerative cerebellar diseases, currently, no effective treatment that would substantially restore cerebellar functions is available. Neurotransplantation could be a promising therapy for such cases. Nevertheless, there are still severe limitations for routine clinical use. The aim of the work was to assess volume and morphology and functional impact on motor skills of an embryonic cerebellar graft injected in the form of cell suspension in Lurcher mutant and wild-type mice of the B6CBA and C3H strains after a 6-month survival period. The grafts survived in the majority of the mice. In both B6CBA and C3H Lurcher mice, most of the grafts were strictly delimited with no tendency to invade the host cerebellum, while in wild-type mice, graft-derived Purkinje cells colonized the host's cerebellum. In C3H Lurcher mice, but not in B6CBA Lurchers, the grafts had smaller volume than in their wild-type counterparts. C3H wild-type mice had significantly larger grafts than B6CBA wild-type mice. No positive effect of the transplantation on performance in the rotarod test was observed. The findings suggest that the niche of the Lurcher mutant cerebellum has a negative impact on integration of grafted cells. This factor seems to be limiting for specific functional effects of the transplantation therapy in this mouse model of cerebellar degeneration.

Impaired spatial performance in cerebellar-deficient Lurcher mice is not associated with their abnormal stress response

Both humans and laboratory animals suffering from cerebellar lesions exhibit cognitive as well as many emotional and behavioral abnormalities. These latter have been already observed in the cerebellar mutant mice currently used to highlight some aspect of autism spectrum disorders. The aim of this study was to investigate the influence of cerebellar-related stress response abnormalities on spatial learning and memory. Cerebellar-deficient Lurcher mutant mice were exposed to water environment without active escape possibility and then tested for spatial learning in the Morris water maze. As a marker of stress intensity we measured corticosterone in urine. Finally, the volumes of individual components of the adrenal gland were estimated. Though having spatial navigation deficit in the water maze, Lurcher mice preserved a substantial residuum of learning capacity. Lurcher mutants had a higher increase of corticosterone level after exposure to the water environment than wild type mice. We did not observe any decrease of this physiological stress marker between the start and the end of the spatial navigation task, despite significant improvement of behavioral performances. Furthermore, zona fasciculata and zona reticularis of the adrenal cortex as well as the adrenal medulla were larger in Lurcher mice, reflecting high stress reactivity. We conclude that for both genotypes water exposure was a strong stressor and that there was no habituation to the experiment independently to the increasing controllability of the stressor (e.g. ability to find the escape platform). Based on these findings, we suggest that the enhanced stress response to water exposure is not the main factor explaining the spatial deficits in these cerebellar mutant mice.

Impact of Non-Invasively Induced Motor Deficits on Tibial Cortical Properties in Mutant Lurcher Mice.

It has been shown that Lurcher mutant mice have significantly altered motor abilities, regarding their motor coordination and muscular strength because of olivorecebellar degeneration. We assessed the response of the cross-sectional geometry and lacuno-canalicular network properties of the tibial mid-diaphyseal cortical bone to motor differences between Lurcher and wild-type (WT) male mice from the B6CBA strain. The first data set used in the cross-sectional geometry analysis consists of 16 mice of 4 months of age and 32 mice of 9 months of age. The second data set used in the lacunar-canalicular network analysis consists of 10 mice of 4 months of age. We compared two cross-sectional geometry and four lacunar-canalicular properties by I-region using the maximum and minimum second moment of area and anatomical orientation as well as H-regions using histological differences within a cross section. We identified inconsistent differences in the studied cross-sectional geometry properties between Lurcher and WT mice. The biggest significant difference between Lurcher and WT mice is found in the number of canaliculi, whereas in the other studied properties are only limited. Lurcher mice exhibit an increased number of canaliculi (p < 0.01) in all studied regions compared with the WT controls. The number of canaliculi is also negatively correlated with the distance from the centroid in the Lurcher and positively correlated in the WT mice. When the Lurcher and WT sample is pooled, the number of canaliculi and lacunar volume is increased in the posterior Imax region, and in addition, midcortical H-region exhibit lower number of canaliculi, lacuna to lacuna distance and increased lacunar volume. Our results indicate, that the importance of precise sample selection within cross sections in future studies is highlighted because of the histological heterogeneity of lacunar-canalicular network properties within the I-region and H-region in the mouse cortical bone.

The Cerebellum and SIDS: Disordered Breathing in a Mouse Model of Developmental Cerebellar Purkinje Cell Loss during Recovery from Hypercarbia.

The cerebellum assists coordination of somatomotor, respiratory, and autonomic actions. Purkinje cell alterations or loss appear in sudden infant death and sudden death in epilepsy victims, possibly contributing to the fatal event. We evaluated breathing patterns in 12 wild-type (WT) and Lurcher mutant mice with 100% developmental cerebellar Purkinje cell loss under baseline (room air), and recovery from hypercapnia, a concern in sudden death events. Six mutant and six WT mice were exposed to 4-min blocks of increasing CO2 (2, 4, 6, and 8%), separated by 4-min recovery intervals in room air. Breath-by-breath patterns, including depth of breathing and end-expiratory pause (EEP) durations during recovery, were recorded. No baseline genotypic differences emerged. However, during recovery, EEP durations significantly lengthened in mutants, compared to WT mice, following the relatively low levels of CO2 exposure. Additionally, mutant mice exhibited signs of post-sigh disordered breathing during recovery following each exposure. Developmental cerebellar Purkinje cell loss significantly affects compensatory breathing patterns following mild CO2 exposure, possibly by inhibiting recovery from elevated CO2. These data implicate cerebellar Purkinje cells in the ability to recover from hypercarbia, suggesting that neuropathologic changes or loss of these cells contribute to inadequate ventilatory recovery to increased environmental CO2. Multiple disorders, including sudden infant death syndrome (SIDS) and sudden unexpected death in epilepsy (SUDEP), appear to involve both cardiorespiratory failure and loss or injury to cerebellar Purkinje cells; the findings support the concept that such neuropathology may precede and exert a prominent role in these fatal events.

Smaller Absolute Quantities but Greater Relative Densities of Microvessels Are Associated with Cerebellar Degeneration in Lurcher Mice.

Degenerative affections of nerve tissues are often accompanied by changes of vascularization. In this regard, not much is known about hereditary cerebellar degeneration. In this study, we compared the vascularity of the individual cerebellar components and the mesencephalon of 3-month-old wild type mice (n = 5) and Lurcher mutant mice, which represent a model of hereditary olivocerebellar degeneration (n = 5). Paraformaldehyde-fixed brains were processed into 18-μm thick serial sections with random orientation. Microvessels were visualized using polyclonal rabbit anti-laminin antibodies. Then, the stacks comprised of three 5-μm thick optical sections were recorded using systematic uniform random sampling. Stereological assessment was conducted based on photo-documentation. We found that each of the cerebellar components has its own features of vascularity. The greatest number and length of vessels were found in the granular layer; the number of vessels was lower in the molecular layer, and the lowest number of vessels was observed in the cerebellar nuclei corresponding with their low volume. Nevertheless, the nuclei had the greatest density of blood vessels. The reduction of cerebellum volume in the Lurcher mice was accompanied by a reduction in vascularization in the individual cerebellar components, mainly in the cortex. Moreover, despite the lower density of microvessels in the Lurcher mice compared with the wild type mice, the relative density of microvessels in the cerebellar cortex and nuclei was greater in Lurcher mice. The complete primary morphometric data, in the form of continuous variables, is included as a supplement. Mapping of the cerebellar and midbrain microvessels has explanatory potential for studies using mouse models of neurodegeneration.

Visual evoked potentials in Lurcher mutant mice: infuence of retinal degeneration as an independent pathogeny

Visual evoked potentials in Lurcher mutant mice: infuence of retinal degeneration as an independent pathogeny

Transplantation and Stem Cell Therapy for Cerebellar Degenerations.

Stem cell-based and regenerative therapy may become a hopeful treatment for neurodegenerative diseases including hereditary cerebellar degenerations. Neurotransplantation therapy mainly aims to substitute lost cells, but potential effects might include various mechanisms including nonspecific trophic effects and stimulation of endogenous regenerative processes and neural plasticity. Nevertheless, currently, there remain serious limitations. There is a wide spectrum of human hereditary cerebellar degenerations as well as numerous cerebellar mutant mouse strains that serve as models for the development of effective therapy. By now, transplantation has been shown to ameliorate cerebellar function, e.g. in Purkinje cell degeneration mice, Lurcher mutant mice and mouse models of spinocerebellar ataxia type 1 and type 2 and Niemann-Pick disease type C. Despite the lack of direct comparative studies, it appears that there might be differences in graft development and functioning between various types of cerebellar degeneration. Investigation of the relation of graft development to specific morphological, microvascular or biochemical features of the diseased host tissue in various cerebellar degenerations may help to identify factors determining the fate of grafted cells and potential of their functional integration.

Transplantation of Embryonic Cerebellar Grafts Improves Gait Parameters in Ataxic Lurcher Mice.

Hereditary cerebellar ataxias are severe diseases for which therapy is currently not sufficiently effective. One of the possible therapeutic approaches could be neurotransplantation. Lurcher mutant mice are a natural model of olivocerebellar degeneration representing a tool to investigate its pathogenesis as well as experimental therapies for hereditary cerebellar ataxias. The effect of intracerebellar transplantation of embryonic cerebellar solid tissue or cell suspension on motor performance in adult Lurcher mutant and healthy wild-type mice was studied. Brain-derived neurotrophic factor level was measured in the graft and adult cerebellar tissue. Gait analysis and rotarod, horizontal wire, and wooden beam tests were carried out 2 or 6 months after the transplantation. Higher level of the brain-derived neurotrophic factor was found in the Lurcher cerebellum than in the embryonic and adult wild-type tissue. A mild improvement of gait parameters was found in graft-treated Lurcher mice. The effect was more marked in cell suspension grafts than in solid transplants and after the longer period than after the short one. Lurcher mice treated with cell suspension and examined 6 months later had a longer hind paw stride (4.11 vs. 3.73 mm, P < 0.05) and higher swing speed for both forepaws (52.46 vs. 32.79 cm/s, P < 0.01) and hind paws (63.46 vs. 43.67 cm/s, P < 0.001) than controls. On the other hand, classical motor tests were not capable of detecting clearly the change in the motor performance. No strong long-lasting negative effect of the transplantation was seen in wild-type mice, suggesting that the treatment has no harmful impact on the healthy cerebellum.

Mesenchymal stem cells as a potential therapeutic tool for spinocerebellar ataxia.

Spinocerebellar ataxia (SCA) is a devastating progressive neurodegenerative disorder, for which no effective treatments have been developed. However, some studies have shown that an intracerebellar or intrathecal injection of mesenchymal stem cells (MSCs) was partially effective in some genetic mouse models of cerebellar ataxia such as SCA1 and Lurcher mutant. MSCs likely exert their therapeutic efficacy by secreting innate factors to induce neuronal growth and synaptic connection and reduce apoptosis. In this review, we introduce the therapeutic influence of MSCs on each mouse model for cerebellar ataxia and the possible mechanisms underlying the action of MSCs. We also introduce studies on the safety and effectiveness of umbilical cord MSCs for patients with SCA.

Fear-related behaviors in Lurcher mutant mice exposed to a predator.

The Lurcher mutant mice are characterized by massive cerebellar cortex degeneration. Besides their motor and cognitive disturbances, they exhibit both exaggerated blood corticosterone (CORT) level surge and behavioral disinhibition when confronted to anxiogenic conditions (i.e. to a potential threat). In this study, we assessed if such physiological and behavioral hyperactivity was also detectable in a fear-eliciting situation (actual threat). For this purpose, the behaviors and CORT level elevations in Lurcher mice were compared with those of littermate controls in the predator exposure test: mice were exposed either to a rat (exposure) or to a brief wave of the experimenter's hand (sham exposure). While the basal CORT concentrations (24 h before testing) were not significantly different between mice of both genotypes, the post-exposure ones were higher in Lurcher than in control mice whatever the condition of the experimental design (exposure or sham exposure). Predator exposure did not provoke significant increase of CORT levels whatever the genotype. On the contrary, our data clearly showed that fear-related behaviors of cerebellar mutants facing a real threat were exacerbated in comparison to those of control mice. These results suggest that the cerebellar cortex not only participates to fear conditioning and anxiety but also actively contributes to the modulation of the innate fear-related behaviors.

Impaired hypercarbic and hypoxic responses from developmental loss of cerebellar Purkinje neurons: implications for sudden infant death syndrome.

Impaired responsivity to hypercapnia or hypoxia is commonly considered a mechanism of failure in sudden infant death syndrome (SIDS). The search for deficient brain structures mediating flawed chemosensitivity typically focuses on medullary regions; however, a network that includes Purkinje cells of the cerebellar cortex and its associated cerebellar nuclei also helps mediate responses to carbon dioxide (CO2) and oxygen (O2) challenges and assists integration of cardiovascular and respiratory interactions. Although cerebellar nuclei contributions to chemoreceptor challenges in adult models are well described, Purkinje cell roles in developing models are unclear. We used a model of developmental cerebellar Purkinje cell loss to determine if such loss influenced compensatory ventilatory responses to hypercapnic and hypoxic challenges. Twenty-four Lurcher mutant mice and wild-type controls were sequentially exposed to 2% increases in CO2 (0-8%) or 2% reductions in O2 (21-13%) over 4 min, with return to room air (21% O2/79% N2/0% CO2) between each exposure. Whole body plethysmography was used to continuously monitor tidal volume (TV) and breath frequency (f). Increased f to hypercapnia was significantly lower in mutants, slower to initiate, and markedly lower in compensatory periods, except for very high (8%) CO2 levels. The magnitude of TV changes to increasing CO2 appeared smaller in mutants but only approached significance. Smaller but significant differences emerged in response to hypoxia, with mutants showing smaller TV when initially exposed to reduced O2 and lower f following exposure to 17% O2. Since cerebellar neuropathology appears in SIDS victims, developmental cerebellar neuropathology may contribute to SIDS vulnerability.

The effect of genetic background on behavioral manifestation of Grid2Lc mutation

Mutant mice are commonly used models of hereditary diseases. Nevertheless, these mice have phenotypic traits of the original strain, which could interfere with the manifestation of the mutation of interest. Lurcher mice represent a model of olivocerebellar degeneration, which is caused by the Grid2Lc mutation. Lurchers show ataxia and various cognitive and behavioral abnormalities. The most commonly used strains of Lurcher mice are B6CBA and C3H, but there is no information about the role of genetic background on the Grid2Lc manifestation. The aim of this work was to compare spatial navigation in the Morris water maze, spontaneous activity in the open field and motor skills on the horizontal wire, slanted ladder and rotarod in B6CBA and C3H Lurcher mutant and wild type mice. The study showed impaired motor skills and water maze performance in both strains of Lurcher mice. Both C3H Lurcher and C3H wild type mice had poorer performances in the water maze task than their B6CBA counterparts. In the open field test, C3H mice showed higher activity and lower thigmotaxis. The study showed that genetic backgrounds can modify manifestations of the Lurcher mutation. In this case, B6CBA Lurcher mice models probably have more validity when studying the behavioral aspects of cerebellar degeneration than C3H Lurcher mice, since they do not combine abnormalities related to the Grid2Lc mutation with strain-specific problems.

Changes in the Distribution of theα3 Na+/K+ATPase Subunit in Heterozygous Lurcher Purkinje Cells as a Genetic Model of Chronic Depolarization during Development

A common assumption of excitotoxic mechanisms in the nervous system is that the ionic imbalance resulting from overstimulation of glutamate receptors and increased Na+ and Ca++ influx overwhelms cellular energy metabolic systems leading to cell death. The goal of this study was to examine how a chronic Na+ channel leak current in developing Purkinje cells in the heterozygous Lurcher mutant (+/Lc) affects the expression and distribution of the α3 subunit of the Na+/K+ ATPase pump, a key component of the homeostasis system that maintains ionic equilibrium in neurons. The expression pattern of the catalytic α3 Na+/K+ ATPase subunit was analyzed by immunohistochemistry, histochemistry, and Western Blots in wild type (WT) and +/Lc cerebella at postnatal days P10, P15, and P25 to determine if there are changes in the distribution of active Na+/K+ ATPase subunits in degenerating Purkinje cells. The results suggest that the expression of the catalytic α3 subunit is altered in chronically depolarized +/Lc Purkinje cells, although the density of active Na+/K+ ATPase pumps is not significantly altered compared with WT in the cerebellar cortex at P15, and then declines from P15 to P25 in the +/Lc cerebellum as the +/Lc Purkinje cells degenerate.

Glutamate Dysfunction Associated with Developmental Cerebellar Damage: Relevance to Autism Spectrum Disorders

Neural abnormalities commonly associated with autism spectrum disorders include prefrontal cortex (PFC) dysfunction and cerebellar pathology in the form of Purkinje cell loss and cerebellar hypoplasia. It has been reported that loss of cerebellar Purkinje cells results in aberrant dopamine neurotransmission in the PFC which occurs via dysregulation of multisynaptic efferents from the cerebellum to the PFC. Using a mouse model, we investigated the possibility that developmental cerebellar Purkinje cell loss could disrupt glutamatergic cerebellar projections to the PFC that ultimately modulate DA release. We measured glutamate release evoked by local electrical stimulation using fixed-potential amperometry in combination with glutamate selective enzyme-based recording probes in urethane-anesthetized Lurcher mutant and wildtype mice. Target sites included the mediodorsal and ventrolateral thalamic nuclei, reticulotegmental nuclei, pedunculopontine nuclei, and ventral tegmental area. With the exception of the ventral tegmental area, the results indicated that in comparison to wildtype mice, evoked glutamate release was reduced in Lurcher mutants by between 9 and 72% at all stimulated sites. These results are consistent with the notion that developmental loss of cerebellar Purkinje cells drives reductions in evoked glutamate release in cerebellar efferent pathways that ultimately influence PFC dopamine release. Possible mechanisms whereby reductions in glutamate release could occur are discussed.