scholarly journals The intact central nervous system of the newborn opossum in long-term culture: fine structure and GABA-mediated inhibition of electrical activity

1991 ◽  
Vol 161 (1) ◽  
pp. 25-41 ◽  
Author(s):  
R. R. Stewart ◽  
D. J. Zou ◽  
J. M. Treherne ◽  
K. Mollgard ◽  
N. R. Saunders ◽  
...  

1. The entire central nervous system (CNS) of the newly born, South American opossum (Monodelphis domestica) was isolated and maintained in basal medium, Eagle's (BME) with 0.2% foetal calf serum and antibiotics. Isolated CNS preparations remained electrically excitable for up to 10 days. The fine structure of the spinal cord was normal after 5 days in culture: axons, synapses, dendrites and glia were virtually unchanged. Signs of degeneration were evident only in dorsal areas of the spinal cord, which had been denervated by removal of the dorsal root ganglia during dissection. 2. Amino acid transmitters such as glycine, glutamate, N-methyl-D-aspartate (NMDA) and gamma-aminobutyric acid (GABA), applied to the bathing fluid, rapidly and reversibly inhibited synaptic transmission in cervical segments of the spinal cord. GABA (10–100 mumol l-1) produced a dose-dependent reduction in the magnitude of ventral root responses evoked by dorsal root stimulation. GABA also inhibited synaptically activated compound action potentials produced by spinal cord stimulation. Dose-response curves for GABA obtained in different preparations were highly reproducible. 3. Both GABAA and GABAB receptors were reversibly activated by selective agonists and inhibited by specific antagonists. The actions of GABA were potentiated by benzodiazepines, competitively antagonised by bicuculline (a selective GABAA antagonist) and mimicked by muscimol (a GABAA agonist). Baclofen (a specific GABAB agonist) also inhibited electrical activity and was competitively antagonised by the GABAB antagonist, CGP 35348. 4. After 5 days of culture in BME or minimal essential medium (MEM), GABA dose-response curves were unchanged from those observed immediately after removal of the CNS. The inhibitory potency of baclofen was also unaffected by culture in BME. By contrast, after 5 days of culture in MEM, baclofen no longer inhibited electrical activity. This difference between BME and MEM could be attributed to the higher content of L-histidine in MEM. Thus, addition of 150 mumol l-1 L-histidine to BME produced similar results to culture in MEM: the inhibitory action of baclofen was virtually abolished after 3–5 days. L-Histidine had no effect on freshly dissected preparations. Chronic application of L-histidine did not affect glycine or glutamate responses after 5 days. Addition of D-histidine or other amino acids, such as arginine, to BME did not abolish the responses to baclofen. 5. These results show that the isolated CNS of the newborn opossum survives well in long-term culture and that it provides a useful preparation to study receptor development and plasticity of an intact mammalian CNS in vitro.(ABSTRACT TRUNCATED AT 400 WORDS)

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Guojia Du ◽  
Yandong Li ◽  
Pan Wu ◽  
Xin Wang ◽  
Riqing Su ◽  
...  

Abstract Background To explore central nervous system (CNS) involvement in this disease, from the perspectives of diagnosis, treatment, and misdiagnosis Methods Twenty-eight patients with CNS echinococcosis were included in this retrospective study, including 18 males (64.3%) and 10 (35.7%) females. The average age of all the patients were 23.5 years (ranged 4–60 years). Twenty-three (23) patients (82.1%) received the first surgical resection in our hospital. Five (5) patients (17.9%) gave up surgical treatment for multiple-organ hydatidosis and previous surgery history at other hospitals, and albendazole was applied for a long-term (3–6 months) adjunct therapy for the 5 patients. The average follow-up time was 8 years. Results For the 28 patients, 23 cases received surgical treatments, and the diagnosis was confirmed by pathological examinations. The diagnosis of 4 cases of brain echinococcosis and 2 cases of spinal cord echinococcosis could not be confirmed, resulting in a misdiagnosis rate of 21.4% (6/28). For the pathological examination, a total of 17 cases were infected with Echinococcus granulosus (including 2 cases of spinal cord echinococcosis), and 6 cases were infected with Echinococcus alveolaris. Conclusion The diagnosis should be specifically considered in endemic regions. The clinical features of CNS hydatidosis were intracranial space-occupying lesions. For the treatment, the surgical removal of cysts should be necessary. In addition, the adjuvant therapy with drug and intraoperative prophylaxis is also suggested. The misdiagnosis may have resulted from atypical clinical features and radiographic manifestations, as well as the accuracy of hydatid immunologic test.


Author(s):  
Benjamin M. Greenberg ◽  
Allen Desena

Acute disseminated encephalomyelitis (ADEM) is a rare inflammatory disorder of the central nervous system (CNS) that can be fatal or lead to long-term disability. Various triggers have been identified in children and adults, which presumably cause an autoimmune response targeting myelin. The resulting inflammation causes demyelination and edema of the brain, spinal cord, and optic nerves. Depending on which portion of the CNS is affected, patients will experience a variety of symptoms including weakness, numbness, ataxia, encephalopathy, and seizures. Treatment is currently focused on reducing the amount of inflammation and supportive care.


2001 ◽  
Vol 64 (12) ◽  
pp. 2047-2052 ◽  
Author(s):  
G. R. SCHMIDT ◽  
R. S. YEMM ◽  
K. D. CHILDS ◽  
J. P. O'CALLAGHAN ◽  
K. L. HOSSNER

We report the development and validation of a fluorescent enzyme-linked immunosorbent assay (ELISA) for glial fibrillary acidic protein (GFAP), which can be used as a rapid and sensitive method to detect CNS tissue in meat products. The fluorometric assay is sensitive to 0.2 ng GFAP and has an intra-assay coefficient of variation (CV) of 2.0% and an interassay CV of 14.1%. Bovine spinal cord and brain demonstrate dose-response curves that are parallel to GFAP standards, whereas peripheral sciatic nerve and cervical ganglia also cross-react at high tissue levels. The use of another central nervous system marker, syntaxin 1-B, was not effective for neural tissue detection. Less than 1.0 ng GFAP per mg tissue was found on most beef subprimals and advanced meat recovery (AMR) product. Occasional samples contained higher levels of GFAP, probably because of contamination by the carcass-splitting saw, incomplete removal of the spinal cord, or a chance sampling of a major nerve. Further reduction of CNS content was facilitated by removal of the cervical vertebrae and the spinal canal prior to processing beef chuck bones through AMR equipment. The presence of GFAP was very low (0.037 ng/mg) in beef patties collected from major processors throughout the USA. The presence of normal sausage ingredients or heating the product to 80°C for 60 min did not affect the detection of GFAP. Heating the product to 115°C for 100 min eliminated the detectability of GFAP.


1985 ◽  
Vol 100 (1) ◽  
pp. 74-85 ◽  
Author(s):  
S C Papasozomenos ◽  
L I Binder ◽  
P K Bender ◽  
M R Payne

We have examined the distribution of microtubule-associated protein 2 (MAP2) in the lumbar segment of spinal cord, ventral and dorsal roots, and dorsal root ganglia of control and beta,beta'-iminodipropionitrile-treated rats. The peroxidase-antiperoxidase technique was used for light and electron microscopic immunohistochemical studies with two monoclonal antibodies directed against different epitopes of Chinese hamster brain MAP2, designated AP9 and AP13. MAP2 immunoreactivity was present in axons of spinal motor neurons, but was not detected in axons of white matter tracts of spinal cord and in the majority of axons of the dorsal root. A gradient of staining intensity among dendrites, cell bodies, and axons of spinal motor neurons was present, with dendrites staining most intensely and axons the least. While dendrites and cell bodies of all neurons in the spinal cord were intensely positive, neurons of the dorsal root ganglia were variably stained. The axons of labeled dorsal root ganglion cells were intensely labeled up to their bifurcation; beyond this point, while only occasional central processes in dorsal roots were weakly stained, the majority of peripheral processes in spinal nerves were positive. beta,beta'-Iminodipropionitrile produced segregation of microtubules and membranous organelles from neurofilaments in the peripheral nervous system portion and accumulation of neurofilaments in the central nervous system portion of spinal motor axons. While both anti-MAP2 hybridoma antibodies co-localized with microtubules in the central nervous system portion, only one co-localized with microtubules in the peripheral nervous system portion of spinal motor axons, while the other antibody co-localized with neurofilaments and did not stain the central region of the axon which contained microtubules. These findings suggest that (a) MAP2 is present in axons of spinal motor neurons, albeit in a lower concentration or in a different form than is present in dendrites, and (b) the MAP2 in axons interacts with both microtubules and neurofilaments.


Endocrinology ◽  
2010 ◽  
Vol 151 (10) ◽  
pp. 4908-4915 ◽  
Author(s):  
Ana P. Fernández ◽  
Julia Serrano ◽  
Ricardo Martínez-Murillo ◽  
Alfredo Martínez

Adrenomedullin (AM) is a regulatory peptide, coded by the adm gene, which is involved in numerous physiological processes, including pain sensitivity. Previous studies have shown that intrathecal injection of AM induced hyperalgesia in the rat. Here, we explore pain sensitivity in a mouse conditional knockout for adm in neurons of the central nervous system, including the spinal cord and dorsal root ganglia. Double immunofluorescence in wild-type (WT) animals shows that AM immunoreactivity is found in calcitonin gene-related peptide-positive neurons of the dorsal root ganglia but not in neurons that bind isolectin B4. Mice lacking adm had modified expression of canonical sensorial neuropeptides, having significantly more calcitonin gene-related peptide and less substance P and enkephalin than their WT littermates. Furthermore, the spinal cord of adm knockout mice expressed higher levels of the AM receptor components, suggesting a compensation attempt to deal with the lack of afferent AM signaling. Behavioral nociceptive tests also found differences between genotypes. In the tail-flick test, which measures mostly spinal reflexes, the adm-null animals had a longer latency than their WT counterparts. On the other hand, in the hotplate test, which requires encephalic processing, mice lacking adm had shorter latencies than normal littermates. These results suggest that AM acts as a nociceptive modulator in spinal reflexes, whereas it may have an analgesic function at higher cognitive levels. This study confirms the important role of AM in pain sensitivity processing but unveils a more complex scenario than previously surmised.


2008 ◽  
Vol 2 (5) ◽  
pp. 346-350 ◽  
Author(s):  
Lucy B. Rorke-Adams ◽  
Harold Portnoy

Gliomatosis cerebri is an uncommon but well-established central nervous system neoplasm that occurs primarily in adults. Although the neoplastic process typically arises in the cerebrum, it often spreads to brainstem, cerebellum, or even the spinal cord. In this report the authors document the surgical treatment of a 13-month-old boy whose tumor arose in the cerebellum and over time extended to the thalamus where its growth halted at age 3 years and 10 months. Aside from 2 partial resections the patient underwent neither radiotherapy nor chemotherapy. He is now 21 years old and functions independently.


2018 ◽  
Vol 23 (1) ◽  
pp. 10-13
Author(s):  
James B. Talmage ◽  
Jay Blaisdell

Abstract Injuries that affect the central nervous system (CNS) can be catastrophic because they involve the brain or spinal cord, and determining the underlying clinical cause of impairment is essential in using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), in part because the AMA Guides addresses neurological impairment in several chapters. Unlike the musculoskeletal chapters, Chapter 13, The Central and Peripheral Nervous System, does not use grades, grade modifiers, and a net adjustment formula; rather the chapter uses an approach that is similar to that in prior editions of the AMA Guides. The following steps can be used to perform a CNS rating: 1) evaluate all four major categories of cerebral impairment, and choose the one that is most severe; 2) rate the single most severe cerebral impairment of the four major categories; 3) rate all other impairments that are due to neurogenic problems; and 4) combine the rating of the single most severe category of cerebral impairment with the ratings of all other impairments. Because some neurological dysfunctions are rated elsewhere in the AMA Guides, Sixth Edition, the evaluator may consult Table 13-1 to verify the appropriate chapter to use.


Sign in / Sign up

Export Citation Format

Share Document