Lungfish aestivating activities are locked in distinct encephalic γ-aminobutyric acid type A receptor α subunits.
J Neurosci Res
; 89(3): 418-28, 2011 Mar.
Article
in En
| MEDLINE
| ID: mdl-21259328
ABSTRACT
Ammonia in dipnoans plays a crucial role on neuronal homeostasis, especially for those brain areas that maintain torpor and awakening states in equilibrium. In the present study, specific α subunits of the major neuroreceptor inhibitory complex (GABA(A) R), which predominated during some phases of aestivation of the lungfish Protopterus annectens, turned out to be key adaptive factors of this species. From the isolation, for the first time, of the encoding sequence for GABA(A) R α1, α4 , and α5 subunits in Protopterus annectens, qPCR and in situ hybridization levels of α4 transcript in thalamic (P < 0.001) and mesencephalic (P < 0.01) areas proved to be significantly higher during long aestivating maintenance states. Very evident α5 mRNA levels were detected in diencephalon during short inductive aestivating states, whereas an α4 /α1 turnover characterized the arousal state. Contextually, the recovery of physiological activities appeared to be tightly related to an evident up-regulation of α1 transcripts in telencephalic and cerebellar sites. Surprisingly, TUNEL and amino cupric silver methods corroborated apoptotic and neurodegenerative cellular events, respectively, above all in telencephalon and cerebellum of lungfish exposed to long maintenance aestivating conditions. Overall, these results tend to underlie a novel GABAergic-related ON/OFF molecular switch operating during aestivation of the lungfish, which might have a bearing on sleeping disorders.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Brain
/
Receptors, GABA-A
/
Estivation
/
Fishes
/
Neurons
Limits:
Animals
Language:
En
Journal:
J Neurosci Res
Year:
2011
Document type:
Article
Affiliation country:
Italia
Publication country:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
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US
/
USA