Choline acetyltransferase in the hippocampus is associated with learning strategy preference in adult male rats.
One principle of the multiple memory systems hypothesis posits that the hippocampus-based and striatum-based memory systems compete for control over learning. Consistent with this notion, previous research indicates that the cholinergic system of the hippocampus plays a role in modulating the preference for a hippocampus-based place learning strategy over a striatum-based stimulus--response learning strategy. Interestingly, in the hippocampus, greater activity and higher protein levels of choline acetyltransferase (ChAT), the enzyme that synthesizes acetylcholine, are associated with better performance on hippocampus-based learning and memory tasks. With this in mind, the primary aim of the current study was to determine if higher levels of ChAT and the high-affinity choline uptake transporter (CHT) in the hippocampus were associated with a preference for a hippocampus-based place learning strategy on a task that also could be solved by relying on a striatum-based stimulus--response learning strategy. Results confirmed that levels of ChAT in the dorsal region of the hippocampus were associated with a preference for a place learning strategy on a water maze task that could also be solved by adopting a stimulus-response learning strategy. Consistent with previous studies, the current results support the hypothesis that the cholinergic system of the hippocampus plays a role in balancing competition between memory systems that modulate learning strategy preference.
Department of Psychology, Tulane University, New Orleans, LA 70118, USA. Electronic address: whawley@tulane.edu.
Wayne R
WR
Hawley
Program in Neuroscience, Tulane University, New Orleans, LA 70118, USA.
Christine F
CF
Witty
Department of Psychology, Tulane University, New Orleans, LA 70118, USA; Program in Neuroscience, Tulane University, New Orleans, LA 70118, USA.
Jill M
JM
Daniel
Department of Psychology, Tulane University, New Orleans, LA 70118, USA; Program in Neuroscience, Tulane University, New Orleans, LA 70118, USA.
Gary P
GP
Dohanich
D000818:Animals; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D003463:Cues; D006624:Hippocampus / Q000201:enzymology*; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D026901:Membrane Transport Proteins / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans
D026901:Membrane Transport Proteins; C065637:choline transporter; D002795:Choline O-Acetyltransferase
Choline acetyltransferase; High-affinity choline uptake transporter; Hippocampus; Learning strategy; Multiple memory system