Acute Radiation Effects on Synaptic Activity in the Mammalian Spinal Cord

1963 ◽  
Vol 18 (3) ◽  
pp. 307 ◽  
Author(s):  
Makoto Sato ◽  
Walter Stahl ◽  
George Austin
Author(s):  
Annamaria Grandis ◽  
Anna Gardini ◽  
Claudio Tagliavia ◽  
Giulia Salamanca ◽  
Jean-Marie Graïc ◽  
...  

AbstractThe presence of the lateral cervical nucleus (LCN) in different mammals, including humans, has been established in a number of anatomical research works. The LCN receives its afferent inputs from the spinocervical tract, and conveys this somatosensory information to the various brain areas, especially the thalamus. In the present study, the organization of the calf and pig LCN was examined through the use of thionine staining and immunohistochemical methods combined with morphometrical analyses. Specifically, the localization of calbindin-D28k (CB-D28k) and neuronal nitric oxide synthase (nNOS) in the LCN was investigated using the immunoperoxidase method. Calf and pig LCN appear as a clearly defined column of gray matter located in the three cranial segments of the cervical spinal cord. Thionine staining shows that polygonal neurons represent the main cell type in both species. The calf and pig LCN contained CB-D28k-immunoreactive (IR) neurons of varying sizes. Large neurons are probably involved in the generation of the cervicothalamic pathway. Small CB-D28k-IR neurons, on the other hand, could act as local interneurons. The immunoreactivity for nNOS was found to be mainly located in thin neuronal processes that could represent the terminal axonal portion of nNOS-IR found in laminae III e IV. This evidence suggests that nitric oxide (NO) could modulate the synaptic activity of the glutamatergic spinocervical tracts. These findings suggest that the LCN of Artiodactyls might play an important role in the transmission of somatosensory information from the spinal cord to the higher centers of the brain.


2020 ◽  
Author(s):  
Carlos A. Toro ◽  
Jens Hansen ◽  
Mustafa M. Siddiq ◽  
Kaitlin Johnson ◽  
Wei Zhao ◽  
...  

AbstractSpinal cord injury (SCI) is a devastating form of neurotrauma. Patients who carry one or two ApoE4 alleles show worse functional outcomes and longer hospital stays after SCI but the cellular and molecular underpinnings for this genetic link remain poorly understood. Thus, there is a great need to generate animal models to accurately replicate the genetic determinants of outcomes after SCI to spur development of treatments that improve physical function. Here, we examined outcomes after a moderate contusion SCI of transgenic mice expressing human ApoE3 or ApoE4. ApoE4 mice have worse locomotor function and coordination after SCI. Histological examination revealed greater glial staining in ApoE4 mice after SCI associated with reduced levels of neuronal sprouting markers. Bulk RNA sequencing revealed that subcellular processes (SCPs), such as extracellular matrix organization and inflammatory responses, were highly-ranked among upregulated genes at 7 days after SCI in ApoE4 variants. Conversely, SCPs related to neuronal action potential and neuron projection development were increased in ApoE3 mice at 21 days. In summary, our results reveal a clinically relevant SCI mouse model that recapitulates the influence of ApoE genotypes on post-SCI function in individuals who carry these alleles and suggest that the mechanisms underlying worse recovery for ApoE4 animals involve glial activation and loss of sprouting and synaptic activity.


2021 ◽  
Vol 66 (1) ◽  
pp. 44-48
Author(s):  
I. Galstyan ◽  
M. Konchalovsky ◽  
M. Kozlova ◽  
V. Nugis

Purpose: On clinical examples to estimate a probable contribution of the postponed earlier external radiation of all body in the doses exceeding 1 Gy at development of multiple malignant neoplasms of different localization and a leukaemia. Material and methods: At 8 of 164 patients, it is long observed after the postponed acute radiation syndrome (ARS), multiple oncological diseases are revealed. Dynamics of consecutive forming of solid tumors at 2 patients and also malignant neoplasms and a myelodysplastic syndrome (MDS) with transformation in an acute leukamia at 1 patient is tracked. Observation duration – 31 years, 43 years and 32 years. Results: Availability of medical care to the patients who transferred ARS and high quality of its rendering at all stages (out-patient, stationary) allowed to reveal malignant neoplasms at early stages of development and to achieve an absolute recovery. However eventually at these patients development and other oncological diseases was observed. The given clinical observations allow to assume that at presented cases radiation acted on various stages of carcinogenesis, and its contribution to development of different oncological diseases in all patients was not identical. Conclusion: The analysis of clinical observations allows to assume that radiation contribution to genesis of various oncological diseases at the persons which underwent radiation in the doses causing development of ARS is various. Now in our country there are no approaches to quantitative assessment of a contribution of radiation effects to development of malignant neoplasms in each case. The patients who underwent acute single exposition in doses over 1 Gy have to be considered as having predisposition to development of multiple tumors in the remote terms. In this regard they for life need medical follow up for the purpose of early diagnostics and adequate treatment of the developing malignant neoplasms.


2005 ◽  
Vol 94 (2) ◽  
pp. 1405-1412 ◽  
Author(s):  
Murat Oz ◽  
Keun-Hang Yang ◽  
Michael J. O'Donovan ◽  
Leo P. Renaud

In neonatal spinal cord, we previously reported that exogenous angiotensin II (ANG II) acts at postsynaptic AT1 receptors to depolarize neonatal rat spinal ventral horn neurons in vitro. This study evaluated an associated increase in synaptic activity. Patch clamp recordings revealed that 38/81 thoracolumbar (T7–L5) motoneurons responded to bath applied ANG II (0.3–1 μM; 30 s) with a prolonged (5–10 min) and reversible increase in spontaneous postsynaptic activity, selectively blockable with Losartan ( n = 5) but not PD123319 ( n = 5). ANG-II-induced events included both spontaneous inhibitory (IPSCs; n = 6) and excitatory postsynaptic currents (EPSCs; n = 5). While most ANG induced events were tetrodotoxin-sensitive, ANG induced a significant tetrodotoxin-resistant increase in frequency but not amplitude of miniature IPSCs ( n = 7/13 cells) and EPSCs ( n = 2/7 cells). In 35/77 unidentified neurons, ANG II also induced a tetrodotoxin-sensitive and prolonged increase in their spontaneous synaptic activity that featured both IPSCs ( n = 5) and EPSCs ( n = 4) when tested in the presence of selective amino acid receptor antagonists. When tested in the presence of tetrodotoxin, ANG II was noted to induce a significant increase in the frequency but not the amplitude of mIPSCs ( n = 9) and mEPSCs ( n = 8). ANG also increased spontaneous motor activity from isolated mouse lumbar ventral rootlets. Collectively, these observations support the existence of a wide pre- and postsynaptic distribution of ANG II AT1 receptors in neonatal ventral spinal cord that are capable of influencing both inhibitory and excitatory neurotransmission.


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