Three different test sites assessed the effects of acetyl-1-carnitine (AC) on age-related changes in general health, sensory-motor skills, learning, and memory. Two groups of rats began the experiments at 16 months of age. One group (OLD-AC) was given AC, 75 mg/kg/day, beginning at 16 months. The other group (OLD-CON) was treated identically except it was not given the drug. Beginning at 22 months of age, these rats and a group of young (3-4 months old) rats (YG-CON) were given a series of sensory-motor tasks. AC decreased mortality, and had no reliable effect on body weight, fluid intake, or the general health of the rats. These data indicate that a chronic dose of AC does not interfere with food and water intake, and may increase longevity. An age-related decline of performance occurred in most of the sensory-motor tasks; locomotor activity was reduced in a novel environment and in a runwheel, and the ability to prevent falling was reduced in tests on a taut wire, rotorod, inclined screen, and several types of elevated bridges. An age-related decline of performance did not occur in grooming, or in the latency to initiate several different behaviors. AC had no effect on performance in any sensory-motor task. These data indicate that the improvements produced by AC in some tests of spatial memory may be due to the effects of AC on cognitive abilities rather than on sensory-motor skills.

Acetylcarnitine↗

PubMedDate not supplied

Acetyl-1-carnitine. 2: Effects on learning and memory performance of aged rats in simple and complex mazes.

Acetyl-1-carnitine (AC) was administered via drinking water for six months to one group (OLD-AC) of male F-344 rats beginning at 16 months of age, while another group (OLD-CON) of rats was given water only during that period. The rats were maintained on this treatment throughout behavioral testing, which began at 22 months of age. Performance of the OLD-AC and OLD-CON rats was compared to that of young control (YG-CON) rats on the following set of tasks: spontaneous alternation in the arms of a T-maze, two-choice simultaneous discrimination in the stem of a T-maze, rewarded alternation in the arms of a T-maze, spatial discrimination and reversal on a circular platform, spatial working memory in the radial 8-arm maze, long-term memory in the 14-unit T-maze, and for preference of the light or dark chamber of a two-compartment box. AC improved the long-term memory performance in the split-stem T-maze and on the circular platform but had no discernable effects on performance of aged rats in the other tasks. Possible reasons for the selectivity of this agent's action on behavior are suggested.

Acetylcarnitine↗

PubMedDate not supplied

In vivo assessment of striatal dopamine release in the aged male Fischer 344 rat.

A microdialysis probe was implanted into the striatum of young (4- to 5-month-old) and aged (26- to 27-month-old) Fischer 344 male rats to assess age-related alterations in striatal dopamine (DA) release. Basal levels of DA and the magnitude of DA response evoked by 50 mM and 100 mM high potassium (K+) in aged rats were similar to those in young rats. Furthermore, K(+)-evoked DA release did not correlate with motor performance within either age group. In contrast, amphetamine (250 microM) evoked-DA release of aged rats was significantly lower than that of young rats. Moreover, the enhancement of K(+)-evoked DA release by oxotremorine (500 microM) was significantly attenuated in aged rats. These results indicate that a putative DA release mechanism and its cholinergic modulation of the aged striatum are impaired.

Aging↗

PubMedDate not supplied

Role of parietal cortex and hippocampus in representing spatial information.

Rats with lesions in the parietal cortex or hippocampus as well as cortical lesion and sham-operated controls were tested for acquisition or retention of a cheese board spatial task (dry land version of a water maze task). Results indicated that, relative to controls, rats with hippocampal or parietal cortex lesions were impaired in both acquisition and retention of the spatial task as measured by increased distances traveled to find the correct food location. It is suggested that both the hippocampus and parietal cortex subserve spatial representations required for optimal learning and performance of the cheese board spatial task.

Animals↗

PubMedDate not supplied

Water intoxication and rhabdomyolysis.

A 44-year-old woman was admitted because of stupor. She had consumed 3 liters of water due to thirst after drinking alcohol. Laboratory findings on admission revealed marked hyponatremia (sodium: 115 mEq/l). She was diagnosed as having water intoxication. She recovered from her hyponatremia upon excretion of a large amount of hypotonic urine. Subsequently, however, her serum creatine phosphokinase was markedly elevated at 28,650 IU/l, and her serum myoglobin reached 2,760 ng/ml. The relationship between the occurrence of hyponatremia secondary to water intoxication and rhabdomyolysis was suggested.

Adult↗