Related Experiment Video
Updated: May 5, 2026

Creating Dynamic Images of Short-lived Dopamine Fluctuations with lp-ntPET: Dopamine Movies of Cigarette Smoking
Published on: August 6, 2013
The action of fenfluramine andp-chloramphetamine on serotonergic mechanisms: A comparative study in rat brain nuclei
L M Neckers1, L Bertilsson, E Costa
1Laboratory of Preclinical Pharmacology National Institute of Mental Health, Saint Elizabeths Hospital, 20032, Washington, D.C..
Abstract:
A single injection of fenfluramine orp-chloroamphetamine (PCA) (100 μmol/kg intraperitoneally) decreases the serotonin (5HT) content and the tryptophan hydroxylase activity in various areas of the rat brain. Other reports have shown that a single injection of fenfluramine or PCA causes cytopathological changes in a serotonergic midbrain nucleus which was termed B9 by Dahlstrom and Fuxe (1). Despite this cytopathological change, fenfluramine fails to reduce the tryptophan hydroxylase activity in B9. In hippocampus the decrease of tryptophan hydroxylase elicited by fenfluramine persists for less than 21 days; in contrast PCA reduces the tryptophan hydroxylase activity in hippocampus, striatum, septal nuclei and B9 for longer than 21 days. Probably the decrease of tryptophan hydroxylase elicited by PCA in B9 is due to retrograde degeneration; the intensity and duration of the biochemical lesion elicited by fenfluramine and PCA in serotonergic terminals are a factor in determining the extent of the biochemical lesion in serotonergic cell bodies.
Related Concept Videos
Drugs Affecting Neurotransmitter Release or Uptake
Adrenergic Agonists: Indirect-Acting Agents
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral...
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of...
Antidepressant Drugs: MAOIs and Other Agents
Drugs Affecting GI Tract Motility: Serotonin Receptor Agonists
Antidepressant Drugs: Tricyclics, SSRIs, and SNRIs

