Age-related differences in MK-801- and amphetamine-induced locomotor and stereotypic activities of rats.
Changes in locomotor and stereotypic activities induced by an i.p. injection of either (+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)-cycloheptan-5,10-imine maleate (dizocilpine or MK-801; 0.3 mg/kg) or D-amphetamine sulfate (AMPH; 1.5 mg/kg) were studied in male Mill Hill hooded rats of different age. The following age groups of animals were considered: 28-30 postnatal day (PND)-old rats (peripubertal), 48-50 PND-old (pubertal), 3-month-old (adults), 12-month-old (middle-aged) and 24-month-old (aged). The motor response was measured by an automated animal activity measuring system. The obtained results showed that: (1) in contrast to AMPH, MK-801 induced more pronounced increases of both locomotor and stereotypic activities in peripubertal and pubertal than in adult and aged rats; (2) AMPH induced the same locomotor and stereotypic activity increase in pubertal, adult and middle-aged rats; (3) both AMPH and MK-801 led to a senescence-related decrease of motor activity. These data suggest that the balance of the glutamatergic and dopaminergic systems changes during aging. Such a change is important in understanding schizophrenia and the motor system decline observed in the later stages of life.
Vasilev
V
V
Laboratory of Electrophysiology and Behavior, Department of Neurobiology and Immunology, Institute for Biological Research, 29 November 142, 11060, Belgrade, Yugoslavia.
Veskov
R
R
Janać
B
B
Rakić
Lj
Lj
Stojiljković
M
M
D000375:Aging; D000661:Amphetamine / Q000633:toxicity*; D000818:Animals; D000831:Animals, Newborn; D000697:Central Nervous System Stimulants / Q000633:toxicity*; D016291:Dizocilpine Maleate / Q000633:toxicity*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*; D013239:Stereotyped Behavior / Q000187:drug effects*; D013997:Time Factors
D000697:Central Nervous System Stimulants; D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate; D000661:Amphetamine