Acetylcholine release from the frontal cortex during exploratory activity.
Brain Res
; 784(1-2): 218-27, 1998 Feb 16.
Article
en En
| MEDLINE
| ID: mdl-9518622
ABSTRACT
The activation of the cortical cholinergic system was investigated in 3- and 25-month-old male Wistar rats, by measuring by transversal microdialysis the changes in cortical extracellular acetylcholine (ACh) levels during the performance of simple spontaneous tasks involving exploratory activity and working memory. Two days after implantation of the microdialysis probe in the frontal cortex, object recognition was investigated by either moving the rats from the home cage to the arena containing the objects or keeping the rats in the arena and introducing the objects. Spontaneous alternation was investigated in a Y runway. Young rats discriminated between familiar and novel objects and alternated in the Y runway, while aged rats were unable to discriminate. Whenever rats were moved from the home cage to the arena, ACh release increased (+70-80%) during the exploratory activity. Handling per se had no effect on extracellular ACh levels. When young rats were left in the arena, introduction of the objects caused some exploratory activity and object recognition but no increase in ACh release. ACh release increased by about 300% during spontaneous alternation. In aging rats basal extracellular ACh levels and their increase after placement in the arena were less than half that in young rats. Our work demonstrates that a novel environment activates the cortical cholinergic system, which presumably is associated with arousal mechanisms and selective attentional functions. It also demonstrates that in aging rats the cortical cholinergic hypofunction is associated with a loss of non-spatial working memory.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Acetilcolina
/
Corteza Prefrontal
/
Conducta Exploratoria
Límite:
Animals
Idioma:
En
Revista:
Brain Res
Año:
1998
Tipo del documento:
Article
País de afiliación:
Italia
Pais de publicación:
HOLANDA
/
HOLLAND
/
NETHERLANDS
/
NL
/
PAISES BAJOS
/
THE NETHERLANDS