Electrogenesis in the lower Metazoa and implications for neuronal integration.
J Exp Biol
; 218(Pt 4): 537-50, 2015 Feb 15.
Article
en En
| MEDLINE
| ID: mdl-25696817
ABSTRACT
Electrogenic communication appears to have evolved independently in a variety of animal and plant lineages. Considered here are metazoan cells as disparate as the loose three-dimensional parenchyma of glass sponges, the two-dimensional epithelial sheets of hydrozoan jellyfish and the egg cell membranes of the ctenophore Beroe ovata, all of which are capable of generating electrical impulses. Neuronal electrogenesis may have evolved independently in ctenophores and cnidarians but the dearth of electrophysiological data relating to ctenophore nerves means that our attention is focused on the Cnidaria, whose nervous systems have been the subject of extensive study. The aim here is to show how their active and passive neuronal properties interact to give integrated behaviour. Neuronal electrogenesis, goes beyond simply relaying 'states of excitement' and utilizes the equivalent of a set of basic electrical 'apps' to integrate incoming sensory information with internally generated pacemaker activity. A small number of membrane-based processes make up these analogue applications. Passive components include the decremental spread of current determined by cellular anatomy; active components include ion channels specified by their selectivity and voltage dependence. A recurring theme is the role of inactivating potassium channels in regulating performance. Although different aspects of cnidarian behaviour are controlled by separate neuronal systems, integrated responses and coordinated movements depend on interactions between them. Integrative interactions discussed here include those between feeding and swimming, between tentacle contraction and swimming and between slow and fast swimming in the hydrozoan jellyfish Aglantha digitale.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Fenómenos Electrofisiológicos
/
Fenómenos Fisiológicos del Sistema Nervioso
Límite:
Animals
Idioma:
En
Revista:
J Exp Biol
Año:
2015
Tipo del documento:
Article
País de afiliación:
Reino Unido