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I Spassova

Publications and source records attributed to I Spassova.

13 recordsLinked to original sources
PubMed1988

Fine structure of synapses in the vestibular ganglion of the cat.

The vestibular ganglion of cat contains two distinguishable cell types, the larger and myelinated of which are much more numerous. The smaller and unmyelinated are represented by two cell populations: the first population displays complete Schwann cell ensheathment. The sheath of the second population is usually discontinuous at more than one point. Few axosomatic synapses are present on either cell type and profiles with clear synaptic vesicles predominate on each. The populations of presynaptic profiles in general are one type: a large variety with round synaptic vesicles and an asymmetrical contact. This type contacts the cell soma or the axon hillock surface. Those containing myelinated cells are covered on one side by the myelin sheath of the cell soma. Potential origins for the presynaptic profiles and possible functional significance of the synapses is discussed.

Animals↗
PubMed1984

Observations on the ultrastructure of the axon hillock and initial axon segments of vestibular ganglion cells in the cat.

The axon hillock and initial axon segments of the vestibular ganglion cells in the cat were studied electron microscopically. The results revealed that the two cell processes are not completely comparable from morphological point of view. One of them is larger, with a more straight course, the axoplasm of the initia segment contains mainly longitudinally arranged neurotubules. The second cell process appears smaller in size, the initial segment have a curved course.

Animals↗
PubMed1983

Further observations concerning the motor innervation of the tensor tympani muscle of the cat.

The cat tensor tympani muscle presented an uncommon ultrastructural organization of neuromuscular junctions compared with those in the other striated muscles. In cross sections, individual neuromuscular junctions had very extended contact area of the nerve terminal and muscle fiber, the terminal bouton was covering as a "calyx" the postjunctional muscle fiber. Long basal lamina was interposed between them. The sarcolemma at the level of the nerve terminal had multiple infoldings along its length, or smooth postjunctional muscle membrane was found beneath endings on both fiber types.

Animals↗
PubMed1983

Fine structure of the neurons of the geniculate ganglion of the cat.

The geniculate ganglion of adult cat was studied electron microscopically. The results revealed that the neuronal soma displays different cytoplasmic features and the neurons were classified into two types: light cells and dark cells. Light neurons contained individual clumps of Nissl substance distributed randomly throughout the cytoplasm, dark neurons were characterized by densely packed stacks of Nissl substance in the peripheral cytoplasm. The unipolar cell process showed several ultrastructural peculiarities which differ from multipolar nerve cell axons.

Animals↗
PubMed1982

Fine structure of the neurons and synapses of the vestibular ganglion of the cat.

The vestibular ganglion of 3-month-old cat was studied electron microscopically. The results revealed that the nerve cell bodies are surrounded by thin myelin sheaths which differ in some respects from typical axonal myelin. The neuronal soma displayed different cytoplasmic features and the neurons were classified into two types: light cells and dark cells. Light neurons contained individual clumps of Nissl substance distributed randomly throughout the cytoplasm, dark neurons were characterised by densely packed stacks of Nissl substance in the peripheral cytoplasm. The dark neurons of the ganglion are the only sensory neurons so far described which receive synapses.

Animals↗
PubMed1981

Ultrastructural relationships between the receptor nerve fiber and surrounding lamellae in Krause end-bulbs.

The ultrastructural relationship between the receptor nerve fiber and the surrounding lamellae in Krause end-bulbs was discussed. Many sites of specialized junctions of symmetrical or asymmetrical type along the receptor nerve fiber and the surrounding lamellae were found. In addition, in close vicinity to them, spine-like digitations of the receptor nerve fiber, filled mainly with small clear vesicles, were observed. Mitochondrion-like cholinesterase-positive structures bulging in some cytoplasmic lamellae were also found. It is suggested that a functional link might exist between the specialized junctions, digitations and mitochrondrion-like structures in the transformation of external mechanical stimuli into nerve impulses.

Animals↗