Acetyl-L-carnitine: behavioral, electrophysiological, and neurochemical effects.
Aged rats were chronically administered acetyl-L-carnitine (AC) for 10 months. During this period they were tested on learning and sensorimotor tasks and were then subsequently tested electrophysiologically to assess induction and decay rates of long-term synaptic enhancement (LTE) in the hippocampus. Four groups were tested: young controls (4 mo-con), middle-aged controls (16 mo-con), old controls (24 mo-con), and old AC-treated rats (24 mo-AC). After completion of electrophysiological testing, each rat was sacrificed and investigated for age- or drug-related changes in three neurotransmitter markers; including, NMDA-sensitive glutamate receptors, high affinity choline uptake, and adenosine receptor number in the neocortex, hippocampus or caudate nucleus. Aging impaired spatial learning and there was a robust positive correlation between NMDA receptors in the hippocampus and acquisition of the spatial learning task. Induction of hippocampal LTE was reduced in 24 mo-AC rats and NMDA receptor number and high-affinity choline uptake in the frontal cortex was increased. Several suggestions are offered to explain the action of AC on these neurobiological parameters in old rats.
Davis
S
S
Arizona Research Laboratories, University of Arizona, Tucson 85724.
Markowska
A L
AL
Wenk
G L
GL
Barnes
C A
CA
D000108:Acetylcarnitine / Q000494:pharmacology*; D000375:Aging / Q000523:psychology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001923:Brain Chemistry / Q000187:drug effects*; D004327:Drinking Behavior / Q000187:drug effects; D004594:Electrophysiology; D005071:Evoked Potentials / Q000187:drug effects; D007858:Learning / Q000187:drug effects; D008297:Male; D008568:Memory / Q000187:drug effects; D009473:Neuronal Plasticity / Q000187:drug effects; D018377:Neurotransmitter Agents / Q000378:metabolism; D011597:Psychomotor Performance / Q000187:drug effects; D051381:Rats; D011916:Rats, Inbred F344; D013028:Space Perception / Q000187:drug effects
D018377:Neurotransmitter Agents; D000108:Acetylcarnitine