Dopamine can be released in the substantia nigra for the dendrites of nigrostriatal dopaminergic neurones, to be involved there in the self-regulation of the dopaminergic cells, to control the release of neurotransmitters from nigral afferent fibres and to influence the activity of nigral non-dopaminergic cells.

Dendritic release of dopamine in the substantia nigra

The competitive relationship between d-amphetamine induced stereotypy and locomotor activity indicates the importance of their concurrent evaluation, especially during chronic studies. Repeated injection of 0.5, 1.0, 2.5, 5.0, or 7.5 mg/kg d-amphetamine for 36 successive days, in rats continuously exposed to the experimental chambers, produced a progressive augmentation in stereotypy and/or locomotion (depending on dose) during the 3–4 hr interval following injections (post-injection phase). In contrast, dark phase locomotor activity (8–20 hr after each daily injection) was maximally reduced (30–40% of controls) after the first injection of either 5.0 or 7.5 mg/kg d-amphetamine and gradually declined to this level with repeated injection of 1.0 and 2.5 mg/kg. Carry-over of both the post-injection augmentation and dark phase reduction of locomotion was revealed during amphetamine retest 8 days following discontinuation of daily d-amphetamine injections. Possible mechanisms underlying these behavioral alterations are discussed.

Long-term administration of d-amphetamine: Progressive augmentation of motor activity and stereotypy

The brain as a target for steroid hormone action

A selective inhibitor of serotonin uptake: Lilly 110140, 3-(p-trifluoromethylphenoxy)-N-methyl-3-phenylpropylamine.

A great number of earlier reported experimental data dealing with the role of dopamine in dopamine-loaded structures within the mammalian brain have raised questions concerning the concept of dopamine as an inhibitory agent acting on one type of receptor. A critical review of the anatomical, histochemical, electrophysiological, pharmacological and functional studies reveals that the dopamine-loaded structures are marked by an internal differentiation at various levels. It is attempted to demonstrate that this is due to a heterogeneous distribution of two distinct types of dopamine-receptors, each characterized by their own properties: DAe- and DAi-receptors. Furthermore, the experimental and clinical. implications are discussed in view of the hypothesis that balance between both types of receptors is essential for normal psychomotor functioning.

Excitation-mediating and inhibition-mediating dopamine-receptors: a new concept towards a better understanding of electrophysiological, biochemical, pharmacological, functional and clinical data.

Disposition of newly synthesized amines in cell bodies and terminals of central catechol aminergic neurons. (I) effect of amphetamine and thioproperazine on the metabolism of CA in the caudate nucleus, the substantia nigra and the ventromedial nucleus of the hypothalamus

F. Javoy

Papers

Disposition of newly synthesized amines in cell bodies and terminals of central catechol aminergic neurons. (I) effect of amphetamine and thioproperazine on the metabolism of CA in the caudate nucleus, the substantia nigra and the ventromedial nucleus of the hypothalamus

Effects of adrenalectomy on the turnover of norepinephrine in the rat brain

Blockade of superovulation in the immature rat by increased brain serotonin.

Synthesis and release of serotonin in the median eminence of the rat.