Reversible neural inactivation reveals hippocampal participation in several memory processes.
Studies of patients and animals with brain lesions have implicated the hippocampal formation in spatial, declarative/relational and episodic types of memory. These and other types of memory consist of a series of interdependent but potentially dissociable memory processes-encoding, storage, consolidation and retrieval. To identify whether hippocampal activity contributes to these processes independently, we used a novel method of inactivating synaptic transmission using a water-soluble antagonist of AMPA/kainate glutamate receptors. Once calibrated using electrophysiological and two-deoxyglucose techniques in vivo, drug or vehicle was infused chronically or acutely into the dorsal hippocampus of rats at appropriate times during or after training in a water maze. Our findings indicate that hippocampal neural activity is necessary for both encoding and retrieval of spatial memory and for either trace consolidation or long-term storage.
Riedel
G
G
Department and Centre for Neuroscience, University of Edinburgh Medical School, Crichton Street, Edinburgh EH8 9LE, UK UK.
Micheau
J
J
Lam
A G
AG
Roloff
E L
EL
Martin
S J
SJ
Bridge
H
H
de Hoz
L
L
Poeschel
B
B
McCulloch
J
J
Morris
R G
RG
D000818:Animals; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000502:physiology*; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors; D013777:Tetrazoles / Q000494:pharmacology
D018691:Excitatory Amino Acid Antagonists; D007546:Isoquinolines; D018091:Receptors, AMPA; D013777:Tetrazoles; C082309:tezampanel