Organization of the olfactory center of terrestrial snails (Helix, Limax) revisited: massive axo-somatic innervation of the globuli cells in the procerebrum
-
1
Balaton Limnological Research Institute, Hungarian Academy of Sciences, Comparative Neurobiology Research Group, Department of Experimental Zoology, Hungary
-
2
University of Szeged, Faculty of Natural Sciences and Informatics, Hungary
-
3
Tokushima Bunri University, Laboratory of Functional Biology, Faculty of Pharmaceutical Sciences, Japan
The procerebrum is considered as the CNS region responsible for the central processing of olfactory information in terrestrial snails. Although its cellular organization has been known for a while, there are a number of details to be revealed as its ultrastructure and synaptology. Here we re-investigated the ultrastructure of the globuli cell mass layer of the procerebrum of Helix pomatia and Limax valentianus with the aim to visualize the synaptic contacts established at this level. It has been demonstrated that the globuli cell mass contained a previously not described system of small size local neuropils, located among and surrounded by globuli cell bodies. The axonal elements of the neuropils were found to form series of both specialized and unspecialized axo-somatic contacts with the globuli cell bodies, indicating a massive synaptic influence of the globuli cell activity. The ultrastructurally different synaptic vesicle populations of presynaptic profiles suggest the chemical diversity of inputs. Simple forms of synaptic configurations were also observed, such as: i) axon profiles contacting simultaneously more than one globuli cell bodies, or cell bodies and other axon profiles; ii) presynaptic varicosities forming axo-somatic contacts and receiving additionally synaptic input, which indicates presynaptic modulation; and iii) axon profiles and globuli cell perikarya establishing symmetrical synapse-like contacts. These observations refer to integrative events occurring at the level of the globuli cell mass. Serotonin (5-HT)-immunohistochemistry performed on Helix procerebra revealed a dense perisomatic basket-like innervation of the globuli cell bodies. It suggests, on the one hand, that 5-HT is a major transmitter candidate involved in the axo-somatic interactions, and on the other hand, it supports earlier physiological data showing a role of 5-HT in olfactory learning.
Support: OTKA grant, No. 78224 (K.E.), KAKENHI grant from JSPS, No. 19370030 (E.I.).
Conference:
IBRO International Workshop 2010, Pécs, Hungary, 21 Jan - 23 Jan, 2010.
Presentation Type:
Poster Presentation
Topic:
Cellular neuroscience
Citation:
Elekes
K,
Fekete
ZN,
Battonyai
I,
Mikite
K,
Kobayashi
S and
Ito
E
(2010). Organization of the olfactory center of terrestrial snails (Helix, Limax) revisited: massive axo-somatic innervation of the globuli cells in the procerebrum.
Front. Neurosci.
Conference Abstract:
IBRO International Workshop 2010.
doi: 10.3389/conf.fnins.2010.10.00034
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
19 Apr 2010;
Published Online:
19 Apr 2010.
*
Correspondence:
Károly Elekes, Balaton Limnological Research Institute, Hungarian Academy of Sciences, Comparative Neurobiology Research Group, Department of Experimental Zoology, Tihany, Hungary, elekes@tres.blki.hu