Short toxic methamphetamine schedule impairs object recognition task in male rats.

V. BISAGNO; D. FERGUSON; V. N. LUINE

BRAIN RESEARCH

Elsevier

Lugar: New York; Año: 2002 p. 289 - 301

0006-8993

Performance on Object recognition and object placement memory tasks was evaluated after a short-dosing model of methamphetamine (MA) regime and monoamines and metabolites were measured post-testing. Adult male rats received three injections of 10mg/kg at 2-hour intervals. In striatum DA and 5-HT were depleted by 65% and 79% respectively, no statistical changes were found in pre-frontal cortex, hippocampus, ventral tegmental area (VTA) or substantia nigra. The experimental group also showed less exploratory activity in the open field and the sample trials of both object recognition and object placement tasks. MA groups also showed decreased performance in the object recognition trial (1 h and 2 h inter-trial delays). The fact that the MA group explore less time the objects in the sample trial might indicate deficits in general exploratory drive and/ or deficits to initiate actions. Nevertheless, in the spatial version of the recognition test (Object Placement Task) the experimental group improved performance to the CONTROL group level in two of the three delays (2h and 4h) even with significantly lower total exploration times in the sample trial. Our results demonstrate that a short toxic schedule induced profound changes in neurochemistry (comparable to classic acute toxic models of MA: 4 injections of 10mg/kg) but selective changes in behavioral tasks.