NMDA receptor modulation by D-cycloserine promotes episodic-like memory in mice

Area of Science:

• Neuroscience
• Cognitive Science
• Pharmacology

Background:

• N-methyl-D-aspartate receptors (NMDA-R) are crucial for synaptic plasticity and one-trial learning.
• Episodic-like memory (ELM) in rodents involves recalling the content, location, and temporal context of experienced events.
• Previous research indicated D-cycloserine (DCS) ameliorates stress-induced deficits in ELM.

Purpose of the Study:

• To investigate if DCS can induce ELM in mice under conditions where it is typically absent.
• To assess the promnestic (memory-enhancing) effects of DCS using a specific experimental protocol.

Main Methods:

• Mice were treated with varying doses of DCS (0.2, 2.0, or 20 mg/kg) or saline.
• An experimental protocol was employed to test for integrated memory of object encounters, including temporal order and spatial location.
• Performance was evaluated based on the ability to recall
• what,
• where,
• and
• when
• information.

Main Results:

• Mice receiving 20 mg/kg DCS demonstrated recall of the temporal order and spatial positions of encountered objects.
• This group exhibited integrated ELM, remembering the unique
• what,
• where,
• and
• when
• aspects of their experiences.
• Saline-treated mice and those receiving lower DCS doses (0.2 and 2.0 mg/kg) did not display integrated ELM.

Conclusions:

• This study provides the first evidence that DCS can promote ELM in mice.
• DCS administration can enhance complex memory recall, integrating multiple facets of an experience.