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Impaired spatial memory after ketamine administration in chronic low doses.
C Venâncio1, A Magalhães, L Antunes
1Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal.
Current Neuropharmacology
|September 3, 2011
Summary
Chronic low-dose ketamine (an N-methyl-D-aspartate receptor antagonist) impairs spatial memory and habituation in rats. Higher doses did not produce these cognitive deficits in club drug research.
Area of Science:
- Neuroscience
- Pharmacology
- Behavioral Science
Background:
- Ketamine, an NMDA-receptor antagonist and dissociative anesthetic, is classified as a club drug.
- Previous research links ketamine to impaired working memory and psychopathology.
- Limited data exists on the effects of chronic, sub-anesthetic ketamine doses.
Purpose of the Study:
- To investigate the behavioral and cognitive effects of chronic, sub-anesthetic ketamine administration in adult Wistar rats.
- To determine if dose influences the observed effects.
Main Methods:
- Adult Wistar rats received subcutaneous ketamine (5 or 10 mg/kg) twice daily for 14 days.
- One week post-treatment, rats were assessed using object recognition/location and open field tests.
- Behavioral outcomes included discrimination index, object displacement recognition, and open field activity.
Main Results:
- Rats receiving chronic low-dose ketamine (5 mg/kg) showed impaired object recognition (decreased discrimination index, p<0.05).
- These rats failed to recognize object displacement and exhibited reduced activity in the open field.
- No significant alterations were observed in rats receiving the higher ketamine dose (10 mg/kg).
Conclusions:
- Chronic administration of sub-anesthetic ketamine doses can negatively impact cognitive functions.
- Findings suggest ketamine may impair habituation and spatial representation updating.
- Dose-dependency is indicated, with lower doses causing deficits not seen at higher doses.
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