PubMed Health⌕ Search

Biomedical subjects

R J Ferrante

Publications and source records attributed to R J Ferrante.

At least 55 records · Page 3Linked to original sources

Oral Dyskinesias and striatal lesions in rats after long-term co-treatment with haloperidol and 3-nitropropionic acid.

The pathophysiologic basis of tardive dyskinesia remains unclear. It has been proposed that tardive dyskinesia may be a result of excitotoxic neurodegeneration in the striatum caused by a neuroleptic-induced increase in striatal glutamate release and impaired energy metabolism. To investigate this hypothesis, haloperidol decanoate (38 mg/kg/four weeks intramuscularly) and the succinate dehydrogenase inhibitor 3-nitropropionic acid (8 mg/kg/day via subcutaneous osmotic mini-pumps), were administered alone or together for 16 weeks to four-months-old rats. Control rats received sesame oil intramuscularly and had empty plastic tubes subcutaneously. Vacuous chewing movements, a putative analogue to human tardive dyskinesia, were recorded during and after drug treatment. Haloperidol alone, 3-nitropropionic acid alone, and 3-nitropropionic acid+haloperidol treatments induced an increase in vacuous chewing movements. However, vacuous chewing movements were more pronounced and appeared earlier in rats treated with 3-nitropropionic acid+haloperidol. After drug withdrawal, increases in vacuous chewing movements persisted for 16 weeks in the haloperidol alone and 3-nitropropionic acid+haloperidol group and for four weeks in the 3-nitropropionic acid alone group. Brains from each group were analysed for histopathological alterations. Bilateral striatal lesions were present only in rats with high levels of vacuous chewing movements in the 3-nitropropionic acid+haloperidol-treated rats. Nerve cell depletion and astrogliosis were prominent histopathologic features. There was selective neuronal sparing of both large- and medium-sized aspiny striatal neurons. These results suggest that mild mitochondrial impairment in combination with neuroleptics results in striatal excitotoxic neurodegeneration which may underlie the development of persistent vacuous chewing movements in rats and possibly irreversible tardive dyskinesia in humans.

Analysis of Variance↗

Mice deficient in group IV cytosolic phospholipase A2 are resistant to MPTP neurotoxicity.

Phospholipase A2 (PLA2) enzymes are critical regulators of prostaglandin and leukotriene synthesis, and they may also play an important role in the generation of intracellular free radicals. The group IV cytosolic form of phospholipase A2 (cPLA2) is regulated by changes in intracellular calcium concentration, and the enzyme preferentially acts to release arachidonic acid esterified at the sn-2 position of phospholipids. We examined the susceptibility of mice carrying a targeted mutation of the cPLA2 gene to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity. Mutant mice have no functional cPLA2 activity. Mice that were homozygous for the mutation (cPLA2-/-) were significantly resistant to MPTP-induced dopamine depletion as compared with littermate control (cPLA2+/+) and heterozygous mice (cPLA2+/-). These findings provide evidence that cPLA2 plays a role in MPTP neurotoxicity and suggest that cPLA2 may play a role in the development of Parkinson's disease in humans.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

Increased vulnerability to 3-nitropropionic acid in an animal model of Huntington's disease.

There is substantial evidence for both metabolic dysfunction and oxidative damage in Huntington's disease (HD). In the present study, we used in vivo microdialysis to measure the conversion of 4-hydroxybenzoic acid to 3,4-dihydroxybenzoic acid (3,4-DHBA) as a measure of hydroxyl radical production in a transgenic mouse model of HD, as well as in littermate controls. The conversion of 4-hydroxybenzoic acid to 3,4-DHBA was unchanged in the striatum of transgenic HD mice at baseline. Following administration of the mitochondrial toxin 3-nitropropionic acid (3-NP), there were significant increases in 3,4-DHBA generation in both control and transgenic HD mice, and the increases in the transgenic HD mice were significantly greater than those in controls. Furthermore, administration of 3-NP produced significantly larger striatal lesions in transgenic HD mice than in littermate controls. The present results show increased sensitivity to the mitochondrial toxin 3-NP in transgenic HD mice, which suggests metabolic dysfunction in this mouse model of HD.

Animals↗

Mechanisms of reduced striatal NMDA excitotoxicity in type I nitric oxide synthase knock-out mice.

We investigated the role of neuronal (type I) nitric oxide synthase (nNOS) in NMDA-mediated excitotoxicity in wild-type (SV129 and C57BL/6J) and type I NOS knock-out (nNOS-/-) mice and examined its relationship to apoptosis. Excitotoxic lesions were produced by intrastriatal stereotactic NMDA microinjections (10-20 nmol). Lesion size was dose- and time-dependent, completely blocked by MK-801 pretreatment, and smaller in nNOS knock-out mice compared with wild-type littermates (nNOS+/+, 11.7 +/- 1.7 mm3; n = 8; nNOS-/-, 6. 4 +/- 1.8 mm3; n = 7). The density and distribution of striatal NMDA binding sites, determined by NMDA receptor autoradiography, did not differ between strains. Pharmacological inhibition of nNOS by 7-nitroindazole (50 mg/kg, i.p.) decreased NMDA lesion size by 32% in wild-type mice (n = 7). Neurochemical and immunohistochemical measurements of brain nitrotyrosine, a product of peroxynitrite formation, were increased markedly in wild-type but not in the nNOS-/- mice. Moreover, elevations in 2,3- and 2,5-dihydroxybenzoic acid levels were significantly reduced in the mutant striatum, as a measure of hydroxyl radical production. The importance of apoptosis to NMDA receptor-mediated toxicity was evaluated by DNA laddering and by quantitative histochemistry [terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) staining]. DNA laddering was first detected within lesioned tissue after 12-24 hr. TUNEL-positive cells were first observed at 12 hr, increased in number at 48 hr and 7 d, and were located predominantly in proximity to the lesion border. The density was significantly lower in nNOS-/- mice. Hence, oligonucleosomal DNA breakdown suggesting apoptosis develops as a late consequence of NMDA microinjection and is reduced in nNOS mutants. The mechanism of protection in nNOS-/- mice may relate to decreased oxygen free radical production and related NO reaction products and, in part, involves mechanisms of neuronal death associated with the delayed appearance of apoptosis.

Animals↗

Heterogeneous topographic and cellular distribution of huntingtin expression in the normal human neostriatum.

A striking heterogeneous distribution of topographic and cellular huntingtin immunoreactivity was observed within the human neostriatum using three distinct huntingtin antibodies. Patchy areas of low huntingtin immunoreactivity were present in both the caudate nucleus and putamen, surrounded by an intervening area of greater immunoreactivity. Comparison of huntingtin immunoreactivity with contiguous serial sections stained for enkephalin and calbindin D28k immunoreactivities showed that the topographic heterogeneity of huntingtin immunostaining corresponded to the patch (striosome) and matrix compartments within the striatum. Huntingtin immunoreactivity was confined primarily to neurons and neuropil within the matrix compartment, whereas little or no neuronal or neuropil huntingtin immunostaining was observed within the patch compartment. There was marked variability in the intensity of huntingtin immunolabel among medium-sized striatal neurons, whereas a majority of large striatal neurons were only faintly positive or without any immunoreactivity. Combined techniques for NADPH-diaphorase enzyme histochemistry and huntingtin immunocytochemistry, as well as double immunofluorescence for either nitric oxide synthase or calbindin D28k in comparison with huntingtin expression, revealed a striking correspondence between calbindin D28k and huntingtin immunoreactivities, with little or no colocalization between NADPH-diaphorase or nitric oxide synthase neurons and huntingtin expression. These observations suggest that the selective vulnerability of spiny striatal neurons and the matrix compartment observed in Huntington's disease is associated with higher levels of huntingtin expression, whereas the relative resistance of large and medium-sized aspiny neurons and the patch compartments to degeneration is associated with low levels of huntingtin expression.

Aged↗

Systemic administration of rotenone produces selective damage in the striatum and globus pallidus, but not in the substantia nigra.

Complex I dysfunction has been implicated in the pathogenesis of Parkinson's disease and in the neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which produces a Parkinsonian syndrome in experimental animals and humans. Rotenone is an insecticide which is a specific inhibitor of complex I. We examined the pattern of central nervous system damage produced by i.v. systemic administration of rotenone in rats. Rotenone produced selective damage in the striatum and the globus pallidus, but the substantia nigra was spared. These results are consistent with prior reports suggesting that the selective vulnerability of the substantia nigra to MPTP involves both uptake by the dopamine transporter as well as complex I inhibition, and they show that rotenone produces a unique pattern of central nervous system damage.

Animals↗

Increased 3-nitrotyrosine and oxidative damage in mice with a human copper/zinc superoxide dismutase mutation.

Mutations in copper/zinc superoxide dismutase (SOD1) cause a subset of cases of autosomal dominant familial amyotrophic lateral sclerosis (FALS). Transgenic mice that express these point mutations develop progressive paralysis and motor neuron loss thought to be caused by a gain-of-function of the enzyme. The gain-of-function may be an enhanced ability of the mutant SOD1 to generate .OH radicals or to facilitate peroxynitrite-mediated nitration of proteins. We found significant increases in concentrations of 3-nitrotyrosine, a marker of peroxynitrite-mediated nitration, in upper and lower spinal cord and in cerebral cortex of transgenic mice with the FALS-associated G93A mutation. Malondialdehyde, a marker of lipid peroxidation, was increased in cerebral cortex. 3-Nitrotyrosine-, heme oxygenase-1-, and malondialdehyde-modified protein immunoreactivities were increased throughout SOD1 transgenic mice spinal cord but particularly within motor neurons. These results suggest that the gain-of-function of at least one mutant SOD1 associated with FALS involves increased protein nitration and oxidative damage, which may play a role in neuronal degeneration.

Analysis of Variance↗

Increased 3-nitrotyrosine in both sporadic and familial amyotrophic lateral sclerosis.

The pathogenesis of neuronal degeneration in both sporadic and familial amyotrophic lateral sclerosis (ALS) associated with mutations in superoxide dismutase may involve oxidative stress. A leading candidate as a mediator of oxidative stress is peroxynitrite, which is formed by the reaction of superoxide with nitric oxide. 3-Nitrotyrosine is a relatively specific marker for oxidative damage mediated by peroxynitrite. In the present study, biochemical measurements showed increased concentrations of 3-nitrotyrosine and 3-nitro-4-hydroxyphenylacetic acid in the lumbar and thoracic spinal cord of ALS patients. Increased 3-nitrotyrosine immunoreactivity was observed in motor neurons of both sporadic and familial ALS patients. Neurologic control patients with cerebral ischemia also showed increased 3-nitrotyrosine immunoreactivity. These findings suggest that peroxynitrite-mediated oxidative damage may play a role in the pathogenesis of both sporadic and familial ALS.

Adult↗

Iodoacetate produces striatal excitotoxic lesions.

Impairment of energy production may play a role in the pathogenesis of Huntington's disease (HD). It was recently shown that huntingtin can bind to and possibly inhibit the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). We found that intrastriatal administration of the GAPDH inhibitor iodoacetate produces striatal lesions that are significantly attenuated by removal of the corticostriatal glutamatergic input, consistent with an excitotoxic mechanism. The lesions are accompanied by increased production of hydroxyl free radicals as assessed by conversion of salicylate to 2,3- and 2,5-dihydroxybenzoic acid. In vivo magnetic resonance imaging showed lesions on T2-weighted scans, but there was only a small increase in lactate content. These results show that inhibition of GAPDH produces striatal lesions in vivo and suggest that inhibition of GAPDH could contribute to neuronal degeneration in HD.

Animals↗

Evidence of increased oxidative damage in both sporadic and familial amyotrophic lateral sclerosis.

Some cases of autosomal dominant familial amyotrophic lateral sclerosis (FALS) are associated with mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1), suggesting that oxidative damage may play a role in ALS pathogenesis. To further investigate the biochemical features of FALS and sporadic ALS (SALS), we examined markers of oxidative damage to protein, lipids, and DNA in motor cortex (Brodmann area 4), parietal cortex (Brodmann area 40), and cerebellum from control subjects, FALS patients with and without known SOD mutations, SALS patients, and disease controls (Pick's disease, progressive supranuclear palsy, diffuse Lewy body disease). Protein carbonyl and nuclear DNA 8-hydroxy-2'-deoxyguanosine (OH8dG) levels were increased in SALS motor cortex but not in FALS patients. Malondialdehyde levels showed no significant changes. Immunohistochemical studies showed increased neuronal staining for hemeoxygenase-1, malondialdehyde-modified protein, and OH8dG in both SALS and FALS spinal cord. These studies therefore provide further evidence that oxidative damage may play a role in the pathogenesis of neuronal degeneration in both SALS and FALS.

8-Hydroxy-2'-Deoxyguanosine↗

Chronic 3-nitropropionic acid treatment in baboons replicates the cognitive and motor deficits of Huntington's disease.

We showed recently that chronic administration of the mitochondrial inhibitor 3-nitropropionic acid (3NP) in primates produces various dyskinetic movements and dystonic postures associated with selective striatal lesions displaying many similarities with the pathological features of Huntington's disease (HD). In the present study, we examined whether such a toxic treatment could also induce frontal-type deficits similar to those observed in HD patients. Cognitive performances of 3NP-treated and control baboons were compared using the object retrieval detour task (ORDT), a test designed to assess the functional integrity of the frontostriatal pathway in human and nonhuman primates. During the same time, the motor function of each animal was assessed under spontaneous "no drug" conditions, and time-sampled neurological observations were used after apomorphine administration. A significant impairment in the ORDT was observed in the 3NP animals after 3-6 weeks of treatment, occurring in the absence of spontaneous abnormal movements by in the presence of apomorphine-inducible dyskinesias. Prolonged 3NP treatment resulted in the progressive appearance of spontaneous abnormal movements. Histological evaluation of these animals showed selective bilateral caudate-putamen lesions with sparing of the cerebral cortex, notably the prefrontal cortex. The present study demonstrates that chronic 3NP treatment replicates in primates the basic pathophysiological triad of HD, including spontaneous abnormal movements, progressive striatal degeneration, and a frontostriatal syndrome of cognitive impairment.

Animals↗

Time course of leukocyte adhesion to endothelium in ischemia-reperfusion.

Adhesion of leukocytes (L) to microvascular endothelium (E) is a required step in the L-E interaction leading to tissue injury in ischemia-reperfusion. To assess the optimum period for therapy aimed at ameliorating negative effects of this required step, we investigated the time course of L-E adhesion in the hamster cheek pouch using 2 hr of ischemia and 1 hr of reperfusion in our model of I-R injury (Am. J. Physiol-261: 1626, 1991). Leukocytes adhering (stationary for > or = 30 sec) to postcapillary venules (15-30 microns in diameter) were counted after labeling with acridine orange. Prior to the induction of ischemia, there were no significant differences in the number of adherent leukocytes in each area chosen for study (1.9 +/- 0.6 vs 2.0 +/- 0.3; mean number of leukocytes/100-microns vessel length +/- SD). After 10 and 20 min of reperfusion there was no significant difference in leukocyte adhesion in the ischemic area relative to the control (2.7 +/- 0.5 vs 2.8 +/- 0.8, and 5.3 +/- 2.8 vs 2.4 +/- 0.6, respectively). Leukocyte adherence increased significantly after 30 min of reperfusion and remained elevated at 1 hr of reperfusion in the postischemic area relative to the nonischemic control area (7.8 +/- 1.3 vs 3.6 +/- 0.6, and 8.3 +/- 0.8 vs 4.1 +/- 0.6, respectively; P < 0.01). Leukocyte adhesion in the postischemic area after 30 min reperfusion was not significantly different from the adhesion at the end of 1 hr reperfusion. These data suggest that (1) peak leukocyte adhesion occurs after 30 min of normal reperfusion and (2) postischemic therapeutic intervention may be most beneficial when instituted within this early time period.

Animals↗

Inhibition of white blood cell adhesion at reperfusion decreases tissue damage in postischemic striated muscle.

PURPOSE: To determine the impact of white blood cell (WBC)-endothelium adhesion on tissue damage in the setting of ischemia-reperfusion injury in striated muscle. METHODS: The cremaster muscle of four groups of anesthetized Sprague-Dawley rats was subjected to 4 hours of global, warm (37 degrees C) ischemia and 2 hours of reperfusion. At reperfusion two groups of animals received intravenous injections of monoclonal antibodies directed against either CD11b/CD18 (1B6) or ICAM-1 (1A29). The remaining two groups of animals received saline injections (NoRx) or nonreactive IgG1. In vivo light microscopic techniques were used to determine WBC adherence (number of WBCs per 100 microns postcapillary venules) at different intervals of reperfusion. Muscle viability was assessed with computer-assisted image analysis by measuring the optical intensity of transilluminated muscles after incubation with nitroblue tetrazolium. RESULTS: Our results (mean +/- SEM) demonstrate a significant increase in the number of adherent WBCs relative to baseline (8.0 +/- 0.5) after 4 hours of global ischemia in animals receiving NoRx or IgG1. The significant increase occurred at 30 minutes of reperfusion (17.6 +/- 0.6 and 17.4 +/- 0.4 for NoRx or IgG1, respectively) and was sustained for the duration of the experiment. This increase in adherence was attenuated by 1B6 and 1A29 (12.2 +/- 2.2 and 12.4 +/- 0.8, respectively; p < 0.05 compared with NoRx and IgG1). The decrease in WBC adhesion was associated with a decrease in reperfusion injury to the muscle, as indicated by lower optical intensity values for the 1B6 and 1A29 groups (123 +/- 3 and 129 +/- 2) compared with the NoRx and IgG1 groups (151 +/- 2 and 158 +/- 4). CONCLUSIONS: Our data support an important role for WBCs in the pathogenesis of ischemia-reperfusion injury. Interfering with the WBC-endothelium interactions by using monoclonal antibodies directed against WBCs and endothelial cell adhesion molecules may help to limit ischemia-reperfusion injury.

Animals↗

Motor neurons in Cu/Zn superoxide dismutase-deficient mice develop normally but exhibit enhanced cell death after axonal injury.

The discovery that some cases of familial amyotrophic lateral sclerosis (FALS) are associated with mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1) has focused much attention on the function of SOD1 as related to motor neuron survival. Here we describe the creation and characterization of mice completely deficient for this enzyme. These animals develop normally and show no overt motor deficits by 6 months in age. Histological examination of the spinal cord reveals no signs of pathology in animals 4 months in age. However Cu/Zn SOD-deficient mice exhibit marked vulnerability to motor neuron loss after axonal injury. These results indicate that Cu/Zn SOD is not necessary for normal motor neuron development and function but is required under physiologically stressful conditions following injury.

Animals↗

Chronic mitochondrial energy impairment produces selective striatal degeneration and abnormal choreiform movements in primates.

Although the gene defect responsible for Huntington disease (HD) has recently been identified, the pathogenesis of the disease remains obscure. One potential mechanism is that the gene defect may lead to an impairment of energy metabolism followed by slow excitotoxic neuronal injury. In the present study we examined whether chronic administration of 3-nitropropionic acid (3-NP), an irreversible inhibitor of succinate dehydrogenase, can replicate the neuropathologic and clinical features of HD in nonhuman primates. After 3-6 weeks of 3-NP administration, apomorphine treatment induced a significant increase in motor activity as compared with saline-treated controls. Animals showed both choreiform movements, as well as foot and limb dystonia, which are characteristic of HD. More prolonged 3-NP treatment in two additional primates resulted in spontaneous dystonia and dyskinesia accompanied by lesions in the caudate and putamen seen by magnetic resonance imaging. Histologic evaluation showed that there was a depletion of calbindin neurons, astrogliosis, sparing of NADPH-diaphorase neurons, and growth-related proliferative changes in dendrites of spiny neurons similar to changes in HD. The striosomal organization of the striatum and the nucleus accumbens were spared. These findings show that chronic administration of 3-NP to nonhuman primates can replicate many of the characteristic motor and histologic features of HD, further strengthening the possibility that a subtle impairment of energy metabolism may play a role in its pathogenesis.

Animals↗

Studies of hepatic warm ischemia in the obese Zucker rat.

The effects of warm ischemia were investigated in obese Zucker rats with severe hepatic steatosis in order to develop a nontransplant fatty liver ischemia model. Obese (Ob) and lean (Ln) Zucker rats were subjected to in vivo partial hepatic warm ischemia of 45 or 90 min. Injury was assessed by serum alanine aminotransferase, animal survival, and liver histology. Liver lipids were quantified in control animals. After 90-min ischemia and 2-hr reperfusion, liver malondialdehyde was measured and neutrophils in 12 microscopic fields were counted after esterase staining. After 45 and 90 min of ischemia, Ob animals had significantly higher alanine aminotransferase at 1-hr and 24-hr reperfusion, compared with Ln animals (P < 0.01). After 90 min of ischemia, none of the Ln and 8/9 Ob animals died within 48 hr (P < 0.01). Histologically, Ob animals had more hepatocyte necrosis than did Ln animals. Hepatic neutral and phospholipid content (mg/g) in Ob versus Ln animals was 45.2 +/- 2.6 versus 8.2 +/- 0.7 (P < 0.01) and 36.2 +/- 1.9 versus 27 +/- 2.2 (P < 0.05), respectively. After reperfusion, liver malondialdehyde content increased significantly in Ob animals (8.5 +/- 0.4 vs. 12.3 +/- 0.8 pM/mg protein; P < 0.05), but not in Ln animals. Neutrophils, scant in control livers, increased significantly (P < 0.01) after ischemia/RP, but it increased to a similar degree in Ob and Ln animals. Obese Zucker rats with hepatic steatosis are more susceptible to warm ischemia/reperfusion injury than lean animals, and lipid peroxidation may be an important contributory mechanism. Further studies in this model might help to investigate the human problem.

Alanine Transaminase↗

Involvement of free radicals in excitotoxicity in vivo.

Recent evidence has linked excitotoxicity with the generation of free radicals. We examined whether free radical spin traps can attenuate excitotoxic lesions in vivo. Pretreatment with N-tert-butyl-alpha-(2-sulfophenyl)-nitrone (S-PBN) significantly attenuated striatal excitotoxic lesions in rats produced by N-methyl-D-aspartate (NMDA), kainic acid, and alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA). In a similar manner, striatal lesions produced by 1-methyl-4-phenylpyridinium (MPP+), malonate, and 3-acetylpyridine were significantly attenuated by either S-PBN or alpha-phenyl-N-tert-butylnitrone (PBN) treatment. Administration of S-PBN in combination with the NMDA antagonist MK-801 produced additive effects against malonate and 3-acetylpyridine toxicity. Malonate injections resulted in increased production of hydroxyl free radicals (.OH) as assessed by the conversion of salicylate to 2,3- and 2,5-dihydroxybenzoic acid (DHBA). This increase was significantly attenuated by S-PBN, consistent with a free radical scavenging effect. S-PBN had no effects on malonate-induced ATP depletions and had no significant effect on spontaneous striatal electrophysiologic activity. These results provide the first direct in vivo evidence for the involvement of free radicals in excitotoxicity and suggest that antioxidants may be useful in treating neurologic illnesses in which excitotoxic mechanisms have been implicated.

Animals↗

3-Nitropropionic acid neurotoxicity is attenuated in copper/zinc superoxide dismutase transgenic mice.

The mitochondrial toxin 3-nitropropionic acid (3-NP) produces selective striatal lesions in both experimental animals and humans. The pathogenesis of the lesions involves secondary excitotoxicity that may then lead to free radical generation. To test this further we examined the effects of 3-NP in both transgenic (Tg) mice that carry the complete sequence for the human copper/zinc superoxide dismutase (SOD) gene as well as non-Tg littermate controls. The Tg-SOD mice showed a pronounced attenuation of Nissl-stained striatal lesions compared with non-Tg mice. Systemic administration of 3-NP resulted in production of hydroxyl free radicals as assessed by the conversion of salicylate to 2,3- and 2,5-dihydroxybenzoic acid. This production was attenuated significantly in Tg-SOD mice. In a similar way, 3-NP produced significant increases in 3-nitrotyrosine/tyrosine, a marker for peroxynitrite-mediated damage, which were significantly attenuated in Tg-SOD mice. These results support that oxygen free radicals and peroxynitrite play an important role in the pathogenesis of 3-NP neurotoxicity.

Animals↗