Effect of a subanesthetic dose of ketamine on memory and conscious awareness in healthy volunteers.
Psychopharmacology (Berl)
; 152(3): 283-8, 2000 Oct.
Article
em En
| MEDLINE
| ID: mdl-11105938
RATIONALE: Ketamine is an NMDA receptor antagonist with psychotogenic and cognitive effects in healthy volunteers and schizophrenic patients which has been proposed to be a useful tool to investigate neurobiological basis of schizophrenia. OBJECTIVE: The present study characterized the effects of a subanesthetic dose of ketamine on memory and related subjective states of awareness in healthy volunteers. METHODS: Twenty-six subjects were given either a 60-min ketamine (0.5 mg/kg per hour) or a placebo infusion. To obtain constant plasma ketamine throughout the experiment, ketamine was administered using a computer-controlled infusion system. Subjects carried out episodic memory tasks involving words presented before and during infusion. Memory performance was assessed with recognition and free recall tasks. Subjective states of awareness were assessed using an experiential approach. Levels of psychopathology were evaluated with BPRS. RESULTS: Ketamine impaired performance in free recall and recognition of words presented during, but not before, infusion. There were no differences between groups concerning states of awareness associated with recognition memory. Subjects under ketamine had higher BPRS total scores as well as BPRS negative and positive cluster scores than control subjects. CONCLUSIONS: Ketamine decreases episodic memory performance by impairing encoding, but not retrieval processes. It does not selectively impair subjective states of awareness associated with recognition memory as it has been seen in patients with schizophrenia. Ketamine might mimic the memory impairment associated with acute, but not chronic, forms of schizophrenia.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Conscientização
/
Receptores de N-Metil-D-Aspartato
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Antagonistas de Aminoácidos Excitatórios
/
Ketamina
/
Memória
Tipo de estudo:
Clinical_trials
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Psychopharmacology (Berl)
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Alemanha