Evaluation of Neuropathological Features in the SOD1-G93A Low Copy Number Transgenic Mouse Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) still depicts an incurable and devastating disease. Drug development efforts are mostly based on superoxide dismutase 1 gene (SOD1)-G93A mice that present a very strong and early phenotype, allowing only a short time window for intervention. An alternative mouse model is available, that is based on the same founder line but has a reduced SOD1-G93A copy number, resulting in a weaker and delayed phenotype. To be able to use these SOD1-G93A/low mice for drug testing, we performed a characterization of ALS-typical pathologies. All analyses were performed compared to non-transgenic (ntg) littermates of the same sex and age. In vivo analysis of SOD1-G93A/low mice was performed by weekly body weight measurements, analysis of the survival rate, and measurement of the muscle strength of 24–30 weeks old female and male SOD1-G93A/low mice. Immunofluorescent labeling of SOD1, glial fibrillary acidic protein (GFAP), and ionized calcium-binding adaptor molecule 1 (Iba1) protein was performed in the cervical, thoracic, and lumbar ventral horn of the spinal cord of 24–30 weeks old male and female SOD1-G93A/low mice. The musculus gastrocnemius of male SOD1-G93A/low mice was labeled with fluorophore-conjugated α-bungarotoxin and antibodies against phosphorylated neurofilaments. Fluorescent labeling was detected and quantified by macro-based image analysis. Although SOD1 protein levels were highly increased in both sexes and all age groups, levels strongly peaked in 30 weeks old male SOD1-G93A/low mice. Astrocytosis and activated microglia in the spinal cord ventral horn and phosphorylated neurofilaments in the motor unit of the musculus gastrocnemius progressively increased, while muscle strength progressively decreased in male SOD1-G93A/low mice. In female SOD1-G93A/low mice, only activated microglia increased progressively, while muscle strength was constantly reduced starting at 26 weeks. These differences result in a shorter survival time of male SOD1-G93A/low mice of about 3 weeks compared to female animals. The results suggest that male SOD1-G93A/low mice present a stronger pathology and are, therefore, better suitable to evaluate the efficacy of new drugs against ALS as most pathological features are developing progressively paralleled by a survival time that allows treatment to start before symptom onset.

Coherence parameters of cerebral bioelectric activity and blood serum levels of phosphorylated neurofilaments in comorbid alcohol dependence and affective disorders

Введение. Наряду со многими психическими расстройствами алкогольная зависимость и аффективные расстройства являются результатом взаимодействия генетических, социальных и экологических факторов, что сопровождается морфофункциональными изменениями в центральной нервной системе. Тем не менее, основные причины и механизмы развития коморбидности алкоголизма и аффективных расстройств остаются не до конца ясны. Цель исследования - определение функциональной связности и уровня фосфорилированных нейрофиламентов у пациентов с алкогольной зависимостью и коморбидностью алкогольной зависимости и аффективного расстройства. Методика. Обследовано 60 пациентов после детоксикации: 30 пациентов с алкогольной зависимостью и 30 пациентов с коморбидным течением алкогольной зависимости и аффективного расстройства. Контрольную группу составили 20 психически и соматически здоровых лиц, сопоставимых по полу и возрасту. Исследование биоэлектрической активности головного мозга проводилось при помощи 16-канального энцефалографа. Анализировались общие усредненные значения внутри - и межполушарной когерентности. В сыворотках крови определяли содержание фосфорилированных нейрофиламентов методом твердофазного иммуноферментного анализа на полистироловых планшетах, предварительно покрытых куриными пoликлональными антителами. Результаты. При межгрупповом анализе были выявлены статистически значимо более низкие значения когерентности в правой гемисфере у пациентов с коморбидностью алкогольной зависимости и аффективного расстройства по сравнению с пациентами, страдающими только алкогольной зависимостью. Были обнаружены также статистически значимо более высокие значения концентрации нейрофиламентов в группе пациентов с коморбидностью алкогольной зависимости и аффективного расстройства по сравнению со здоровой группой контроля. При сравнении групп пациентов между собой были обнаружены боле высокие значения концентрации нейрофиламентов у пациентов с коморбидностью алкогольной зависимости и аффективного расстройства на уровне тенденции. Заключение. Наличие коморбидности алкоголизма и аффективных расстройств приводят к нейрофизиологическим изменениям в виде снижения функциональной связности коры головного мозга, особенно в правой гемисфере, а также увеличению степени нейронального повреждения. Background. Similar to many mental disorders, alcohol dependence and affective disorders result from interaction of genetic, social, and environmental factors associated with morpho-functional alterations in the central nervous system. However, major causes and mechanisms of the development of comorbid alcoholism and affective disorders are not fully clear. The aim of this study was to determine the functional connectivity and levels of phosphorylated neurofilaments in patients with alcohol dependence and comorbid alcohol dependence and affective disorder. Methods. 60 patients were evaluated after detoxification, including 30 patients with alcohol dependence and 30 patients with comorbid alcohol dependence and affective disorder. The control group consisted of 20 sex- and age-matched, mentally and somatically healthy individuals. Brain bioelectric activity was recorded with a 16-channel encephalograph. Overall average values of intra- and inter-hemispheric coherence were analyzed. Blood serum concentration of phosphorylated neurofilaments was measured by solid-phase enzyme immunoassay on polystyrene plates pre-coated with chicken polyclonal antibodies. Results. The intergroup analysis showed that coherence values for the right hemisphere were significantly lower in patients with comorbid alcohol dependence and affective disorder compared to patients with alcohol dependence alone (p=0.018). Also, concentrations of neurofilaments were significantly higher in the patient group with comorbid alcohol dependence and affective disorder compared to the healthy control group (p=0.042). Comparison of patient groups showed that neurofilament concentrations had a tendency toward higher values in patients with comorbid alcohol dependence and affective disorder (p=0.092). Conclusion. The presence of comorbid alcoholism and affective disorders leads to neurophysiological alterations evident as reduced functional connectivity of the cerebral cortex, particularly in the right hemisphere, as well as to the increased degree of neuronal damage.

Spongiform neurodegenerative disease in a Persian kitten

A congenital encephalopathy with spongiform degeneration and prominent neuronal apoptosis was observed in a 4-month-old Persian male cat with a history of depressed mental status and ataxia. On clinical examination, signs included right head tilt, ventroflexion of the head and neck, and tetraparesis. Histological examination of the central nervous system revealed multifocal, bilateral and symmetrical vacuolar degeneration of the neuropil, mainly involving the cerebellar and vestibular nuclei area, the caudal colliculi, the mesencephalic nuclei, the tegmental area and the deeper layer of the cerebral cortex. Accumulation of phosphorylated neurofilaments was detected in neuronal perikarya of the deep cortical layers, hippocampus and thalamus. Numerous pyknotic and apoptotic neurons were also observed in the cerebral cortex. These neuropathological changes differ from those observed in previous reports of spongiform degeneration of the grey matter in cats and were suggestive of a congenital neurodegenerative disease.