Spacing spheroids, curl-up and coiled neuritic plexus of the sacral spinal cord of aged dog: Hypothesis based on continued NADPH diaphorase histological observations

ABSTRACTNADPH diaphorase (N-d) neurons distribute in spinal cord and function for visceral sensation and autonomic regulation. N-d positive neurons innervate pelvic organs. In previous investigation, we report that aging-related N-d body (ANB) in the lumbosacral spinal cord in aged rat and megaloneurite in the sacral spinal cord in aged dog. This article was a continued data report of aging-related N-d alterations in aged dog. N-d positivity in aged spinal cord has revealed a certain of morphological profiles in the spinal cord of several species. However, we still found some denoted N-d neurodegenerative changes that we failed to notice in our previous studies when re-examination of the sacral spinal cord of aged dog. In the horizontal section, spacing spheroids in the superficial laminae of the dorsal horn, curl-up and coiled neurites in the intermediate zone were detected in the sacral spinal cord. The ANB and vacuolar neurite were also detected. Vacuolar degeneration also occurred in the dorsal ganglia at the sacral segment. The curl-up and coiled neurites did not occur in the lumbothoracic segment, but the ANB and vacuolar neurite were scatteringly detected in in the lumbothoracic segment of aged dog. The results suggested that the N-d sensory inputs interrupted and disconnected with integration of autonomic centers and output circuits of regulating urogenital organs during the aging. These specialized profiles were speculated that the N-d neurite deterioration of visceral sensory circuit implicated dysfunction of pelvic organs in the aging. Megaloneurite and fiber dilation may make backward reasoning to N-d fiber architecture under normal condition.

Megaloneurite, a giant neurite of vasoactive intestinal peptide and nitric oxide synthase in the aged dog and identification by human sacral spinal cord

Megaloneurite of NADPH diaphorase (NADPH-d) positivity is a new kind of aging-related neurodegeneration and also co-localized with vasoactive intestinal peptide (VIP) in the sacral spinal cord of aged dog and monkey. However, no immunocytochemistry of VIP was exclusively tested in the aged dog and no evidence has been reported in the aged human spinal cord. Aged dogs were used to examine the distribution of VIP immunopositivity in the sacral spinal cord. Immunocytochemistry of VIP and alpha-synuclein were also examined in the aged human spinal cord. The VIP immunopositivity in aged dog was reconfirmed our previous finding illustrated by immunofluorescent study. Megalogneurite was also identified by nitric oxide synthase (NOS) immunoreaction in aged dog. The VIP positive megaloneurites both in age dog and human were detected in dorsal root entry zoon, Lissauer’s tract, dorsal commissural nucleus and anterior commissural gray as well as in the lateral funiculus of the sacral spinal cord exclusive of other segments of spinal cord. Alpha-synuclein positivity was present mini-aggregation and Lewy body in the sacral spinal cord of aged human, that also occurred in the lumber, thoracic and cervical spinal cord. It was firstly tested that VIP megaloneurites occurred in the aged human sacral spinal cord, especially in the white matter. Megaloneurites identified by NADPH-d-VIP-NOS immunoreaction could implicate for the dysfunction of pelvic organs in the aged human being.

Clinical case of cerebral coenurosis in a bison

Objective of research: the analysis of Coenurus cerebralis found in the brain of a bison from Prioksko-Terrasny Nature Biosphere Reserve of the Moscow region. Materials and methods. We have conducted the euthanasia and dissection of the brain of a bison calf due to manifestation of clinical neurological symptoms. Results and discussion: After brain dissection, a strange large dumb-bell shaped vesicle was revealed in the brain tissue. On the inner surface of the vesicle the protoscolexes of helminthwere found. The surrounding brain tissue was significantly atrophied, cerebral meninges were swollen, and fissures were smoothed. To confirm the species belonging of the parasite, a part of surface with 50 protoscolexes was fed to a 6 mo. aged dog. 2,5 months later, Тaenia multiceps proglottids were revealed in dog’s feces, which confirmed the belonging of Coenurus cerebralis. It was found, that the bison might be one of the intermediate hosts for this helminth.

Principles of age-related changes in the canine and feline brain

In the aged dog and cat, especially dog, a cognitive decline develops naturally in many different domains, but at the same time it also exhibits human-like individual variability in the aging process. In the aging dog and cat brain lesions develop spontaneously. Dogs share some morphological characteristics with those of Alzheimer’s disease in man. The canine brain with its plaques and tangles which show oxidative changes, forms a spontaneous model for understanding the early changes and their interrelationships in Alzheimer’s disease. Additionally, the aged dog represents a useful model for the development of preventive or therapeutic interventions to improve aged brain function. These interventions can then be translated into human clinical trials.