Cyclic AMP-regulated opposing and parallel effects of serotonin and dopamine on phototaxis in the Marmorkrebs (marbled crayfish).
Eur J Neurosci
; 46(3): 1863-1874, 2017 Aug.
Article
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| MEDLINE
| ID: mdl-28661085
ABSTRACT
Phototactic behaviours are observed from prokaryotes to amphibians and are a basic form of orientation. We showed that the marbled crayfish displays phototaxis in which the behavioural response reversed from negative to positive depending on external light conditions. Animals reared in a 12-L/12-D light cycle showed negative phototaxis during daytime and positive phototaxis during night-time. Animals reared under constant light conditioning showed negative phototaxis during day- and night-time, while animals reared under constant dark conditioning showed positive phototaxis during day- and night-time. Injection of serotonin leads to a reversal of negative to positive phototaxis in both light/dark-reared and light/light-reared animals while injection of dopamine induced reversed negative phototaxis in dark/dark-reared animals. Four hours of dark adaptation were enough for light/dark-reared animals to reverse phototaxis from negative to positive. Injection of a serotonin 5HT1 receptor antagonist blocked the reverse phototaxis while serotonin 5HT2 receptor antagonists had no effects. Similarly, dark/dark-reared animals reversed to showing negative phototaxis after 4 h of light adaptation. Injection of a dopamine DA1 receptor antagonist blocked this reverse phototaxis, while dopamine DA2 receptor antagonists had no effects. Injection of a cAMP analogue into light/dark-reared animals blocked reverse phototaxis after dark adaptation, while adenylate cyclase inhibitor in dark/dark-reared animals blocked reverse phototaxis after light adaptation. These results strongly suggest that serotonin mediates positive phototaxis owing to decreased cAMP levels, while dopamine-mediated negative phototaxis occurs due to increased cAMP levels. Supporting this, the ratio of serotonin to dopamine in the brain was much higher in dark/dark-reared than light/dark-reared animals.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Dopaminérgicos
/
Dopamina
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Serotonina
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AMP Cíclico
/
Serotoninérgicos
/
Fototaxis
Límite:
Animals
Idioma:
En
Revista:
Eur J Neurosci
Asunto de la revista:
NEUROLOGIA
Año:
2017
Tipo del documento:
Article
País de afiliación:
Japón