Аннотация:Abstract Amphetamine induced vigorous rotational behaviour in rats where the nigrostriatal dopamine (DA) system was unilaterally degenerated by an intracerebral injection of 6‐hydroxydopamine (6‐OH‐DA). The rotational behaviour was analysed in a specially designed “rotometer” and found highly reproducable. The intensity of the rotation was proportional to the extent of degeneration in the DA system. The amphetamine site of action was in all probability presynaptic as amphetamine caused a rotation in the opposite direction as compared to the DA receptor stimulating drug apomorphine. Tyrosine hydroxylase inhibition abolished the amphetamine effect, while reserpine potentiated the effect. Evidence was also obtained that the amphetamine induced release of DA was dependent upon nerve impulses. The rotational behaviour reflected the degree of DA receptor stimulation, but changes in the noradrenaline (NA) transmission seemed to modulate the behaviour. Decreased NA transmission after dopamine‐β‐hydroxylase inhibition increased the rotational behaviour. The unilateral degeneration of the DA system was studied by the changes in posture and movements that occurred during the degeneration. After inhibition of the monoamine oxidase the rats showed a strong rotation beginning on the 23d and ending on the 33d hour after the operation. The rotational behaviour was probably due to degeneration release of DA and equivalent to the degeneration contraction of the nictitating membrane in the peripheral nervous system Amphetamine greatly potentiated the spontaneous degeneration release during this period.
