Neuronal and synaptic organization in the gravity receptor system of the statocyst of Octopus vulgaris

1977 ◽  
Vol 185 (4) ◽  
Author(s):  
W.F. Colmers
Keyword(s):  
Octopus Vulgaris ◽  
Synaptic Organization ◽  
Receptor System ◽  
Gravity Receptor

The angular acceleration receptor system of the statocyst of Octopus vulgaris : morphometry, ultrastructure, and neuronal and synaptic organization

1987 ◽  
Vol 315 (1174) ◽  
pp. 305-343 ◽  
Keyword(s):  
Hair Cells ◽  
Angular Acceleration ◽  
Sensory Cells ◽  
Octopus Vulgaris ◽  
Afferent Neurons ◽  
Synaptic Organization ◽  
Receptor System ◽  
First Order ◽  
Small Primary ◽  
Primary Sensory Cells

The angular acceleration receptor system (crista/cupula system) of the statocyst of Octopus vulgaris has been thoroughly reinvestigated, and detailed information is presented regarding its morphometry, ultrastructure, and neuronal and synaptic organization. In each of the nine crista sections, some receptor hair cells are primary sensory cells with an axon extending from their base. Also, there are large and small secondary sensory hair cells without axons, which make afferent synapses with large and small first-order afferent neurons. The afferent synapses are of two morphologically distinct types, having either a finger-like or a flat postsynaptic process; both can be seen in the same hair cell. In addition to the afferents, there is a dense plexus of efferent fibres in each crista section, and efferent synapses can be seen at the level of the hair cells and of the neurons. The morphometric analysis of the nine crista sections shows obvious differences between the odd-numbered (C1, C3, C5, C7, C9) and the even-numbered (C2, C4, C6, C8) crista sections: they differ in length, in the number of the small primary sensory cells and in the number of the small first-order afferent neurons. Centrifugal cobalt filling of the three crista nerves revealed a disproportionate innervation of the nine crista sections: the anterior crista nerve innervates section C1 and the first half of section C2, the medial crista nerve innervates the second half of section C2, sections C3, C4, C5, and the first half of section C6, and the posterior crista nerve innervates the second half of section C6, and sections C7, C8 and C9. In each of the three crista nerves, only 25% of the total number of axons are afferent fibres, the remaining 75 % are efferent. To each of the nine crista sections a cupula is attached. In the form and size of the cupulae there is again a conspicuous difference between the odd and the even crista sections: a small widebased cupula is attached to each of the odd crista sections, whereas the even crista sections each have a large narrow-based cupula with a small area of attachment. The results are discussed with reference to their functional consequences.

Function of the Gravity Receptor of Octopus vulgaris

Nature ◽  
1970 ◽  
Vol 226 (5248) ◽  
pp. 864-865 ◽  
Author(s):  
HERMANN SCHÖNE ◽  
BERND-ULRICH BUDELMANN
Keyword(s):  
Octopus Vulgaris ◽  
Gravity Receptor

Synaptic organization of the gustatory NST

1994 ◽  
Vol 52 ◽  
pp. 150-151
Author(s):  
M. C. Whitehead
Keyword(s):  
Central Nervous System ◽  
Dendritic Spines ◽  
Fundamental Problem ◽  
Cell Types ◽  
Brain Regions ◽  
Excitatory Synapses ◽  
Solitary Tract ◽  
Synaptic Organization ◽  
Synaptic Junctions ◽  
Afferent Terminals

A fundamental problem in taste research is to determine how gustatory signals are processed and disseminated in the mammalian central nervous system. An important first step toward understanding information processing is the identification of cell types in the nucleus of the solitary tract (NST) and their synaptic relationships with oral primary afferent terminals. Facial and glossopharyngeal (LIX) terminals in the hamster were labelled with HRP, examined with EM, and characterized as containing moderate concentrations of medium-sized round vesicles, and engaging in asymmetrical synaptic junctions. Ultrastructurally the endings resemble excitatory synapses in other brain regions.Labelled facial afferent endings in the RC subdivision synapse almost exclusively with distal dendrites and dendritic spines of NST cells. Most synaptic relationships between the facial synapses and the dendrites are simple. However, 40% of facial endings engage in complex synaptic relationships within glomeruli containing unlabelled axon endings particularly ones termed "SP" endings. SP endings are densely packed with small, pleomorphic vesicles and synapse with both the facial endings and their postsynaptic dendrites by means of nearly symmetrical junctions.

Sign in / Sign up

Export Citation Format

Share Document