Related Experiment Video
Updated: Aug 15, 2026
The Double-H Maze: A Robust Behavioral Test for Learning and Memory in Rodents
Published on: July 8, 2015
Partial unilateral inactivation of the dorsal hippocampus impairs spatial memory in the MWM
José M Cimadevilla1, Ruben Miranda, Laudino López
1Department of Neuroscience, University of Almeria, 04120 Almeria, Spain. jcimadev@ual.es
Abstract:
The hippocampus is one of the more widely studied structures related with spatial memory. In this study, we assessed the effect of unilateral inactivation of the dorsal hippocampus with tetrodotoxin (TTX) on the performance displayed by Wistar rats in the spatial version of the Morris water maze. In experiment 1, we injected into the dorsal hippocampus in two different groups of rats 1 microl of saline solution or 5 ng of TTX in 1 microl of saline each day immediately after the training during four consecutive days. This procedure blocked consolidation and impaired spatial memory in the TTX group. In experiment 2, a new group of subjects was trained in the Morris water maze for 8 days and was administered 1 microl of saline on day 7 (saline session) and TTX on day 8 (TTX session) into the dorsal hippocampus 40 min before the training. Only the treatment with TTX altered the retrieval of memories. These experiments showed that unilateral interventions on the dorsal hippocampus can affect consolidation as well as retrieval of well-established spatial memories.
Insights
Inactivating the dorsal hippocampus with tetrodotoxin (TTX) in rats impaired spatial memory consolidation and retrieval. This highlights the hippocampus's crucial role in forming and accessing spatial memories.
Area of Science:
- Neuroscience
- Behavioral Neuroscience
Background:
- The hippocampus is a key brain structure for spatial memory.
- Understanding its role in memory consolidation and retrieval is crucial.
Purpose of the Study:
- To investigate the effect of dorsal hippocampus inactivation on spatial memory in Wistar rats.
- To differentiate the roles of the hippocampus in memory consolidation versus retrieval.
Main Methods:
- Rats were trained in the spatial version of the Morris water maze.
- Unilateral dorsal hippocampus inactivation was induced using tetrodotoxin (TTX).
- Inactivation occurred either post-training (consolidation) or pre-retrieval (retrieval).
Main Results:
- Post-training TTX injections impaired spatial memory consolidation.
- Pre-retrieval TTX injections impaired the retrieval of established spatial memories.
- Unilateral dorsal hippocampus inactivation affected both memory phases.
Conclusions:
- The dorsal hippocampus is vital for both the consolidation and retrieval of spatial memories.
- Selective inactivation of the dorsal hippocampus can disrupt established spatial memory recall.
