Anandamide modulation of circadian- and stress-dependent effects on rat short-term memory.
Psychoneuroendocrinology
; 108: 155-162, 2019 10.
Article
en En
| MEDLINE
| ID: mdl-31302498
ABSTRACT
The endocannabinoid system plays a key role in the control of emotional responses to environmental challenges. CB1 receptors are highly expressed within cortico-limbic brain areas, where they modulate stress effects on memory processes. Glucocorticoid and endocannabinoid release is influenced by circadian rhythm. Here, we investigated how different stress intensities immediately after encoding influence rat short-term memory in an object recognition task, whether the effects depend on circadian rhythm and if exogenous augmentation of anandamide levels could restore any observed impairment. Two separate cohorts of male adult Sprague-Dawley rats were tested at two different times of the day, morning (inactivity phase) or afternoon (before the onset of the activity phase) in an object recognition task. The anandamide hydrolysis inhibitor URB597 was intraperitoneally administered immediately after the training trial. Rats were thereafter subjected to a forced swim stress under low or high stress conditions and tested 1â¯h after training. Control rats underwent the same experimental procedure except for the forced swim stress (no stress). We further investigated whether URB597 administration might modulate corticosterone release in rats subjected to the different stress conditions, both in the morning or afternoon. The low stressor elevated plasma corticosterone levels and impaired 1â¯h recognition memory performance when animals were tested in the morning. Exposure to the higher stress condition elevated plasma corticosterone levels and impaired memory performance, independently of the testing time. These findings show that stress impairing effects on short-term recognition memory are dependent on the intensity of stress and circadian rhythm. URB597 (0.3â¯mgâ¯kg-1) rescued the altered memory performance and decreased corticosterone levels in all the impaired groups yet leaving memory unaltered in the non-impaired groups.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Ácidos Araquidónicos
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Ritmo Circadiano
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Endocannabinoides
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Alcamidas Poliinsaturadas
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Memoria a Corto Plazo
Límite:
Animals
Idioma:
En
Revista:
Psychoneuroendocrinology
Año:
2019
Tipo del documento:
Article
País de afiliación:
Italia