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Working on catecholamine systems for years, the neuropharmacologist Arvid Carlsson has made a number of important and pioneering discoveries, which have highlighted the key role of these neuronal and peripheral neurotransmitters in brain functions and adrenal regulations. Since then, major advances have been made concerning the distribution of the catecholaminergic systems in particular by studying their rate-limiting enzyme, tyrosine hydroxylase (TH). Recently new methods of tissue transparency coupled with in toto immununostaining and three-dimensional (3D) imaging technologies allow to precisely map TH immunoreactive pathways in the mouse brain and adrenal glands. High magnification images and movies obtained with combined technologies (iDISCO+ and light-sheet microscopy) are presented in this review dedicated to the pioneer work of Arvid Carlsson and his collaborators.

Unfortunately, the given name and family name of the fourth author was incorrectly tagged in the xml data, therefore it is abbreviated wrongly as ‘‘Goazigo AR’’ in Pubmed. The correct given name is Annabelle and family name is Reaux‑Le Goazigo.

Chemokines are not only found in the immune system or expressed in inflammatory conditions: they are constitutively present in the brain in both glial cells and neurons. Recently, the possibility has been raised that they might act as neurotransmitters or neuromodulators. Although the evidence is incomplete, emerging data show that chemokines have several of the characteristics that define neurotransmitters. Moreover, their physiological actions resemble those of neuromodulators in the sense that chemokines usually have few effects by themselves in basal conditions, but modify the induced release of neurotransmitters or neuropeptides. These findings, together with the pharmacological development of agonists and antagonists that are selective for chemokine receptors and can cross the blood-brain barrier, open a new era of research in neuroscience.

International audience; Exposure to psychostimulants and antipsychotics increases neurotensin (NT) gene expression in the striatum and nucleus accumbens. To investigate the contribution of D(3) receptors to these effects we used mice with targeted disruption of the D(3) receptor gene. Basal NT mRNA expression was similar in D(3) receptor mutant mice and wild-type animals. Acute administration of haloperidol increased NT gene expression in the striatum in D(3)+/+, D(3)+/- and D(3)-/- mice. Similarly, acute cocaine and amphetamine induced NT mRNA expression in the nucleus accumbens shell and olfactory tubercle to a comparable extent in D(3) mutants and wild-type mice. Daily injection of cocaine for seven days increased NT mRNA in a restricted population of neurons in the dorsomedial caudal striatum of D(3)+/+ mice, but not in D(3)-/- and D(3)+/- animals. No differences were observed between D(3) receptor mutant mice and wild-type littermates in the locomotor activity and stereotyped behaviors induced by repeated cocaine administration. These findings demonstrate that dopamine D(3) receptors are not necessary for the acute NT mRNA response to drugs of abuse and antipsychotics but appear to play a role in the regulation of NT gene induction in striatal neurons after repeated cocaine. In addition, our results indicate that the acute locomotor response to cocaine and development of psychostimulant-induced behavioral sensitization do not require functional D(3) receptors.

The human neuroblastoma cell line CHP212 was found to express functional high affinity neurotensin (NTS-1) receptor subtype. Based on the functional interactions between neurotensin and dopamine transmission, we have used this cell line to investigate the short- and long-term modulation of tyrosine hydroxylase gene expression by the stable neurotensin agonist JMV 449. After exposure of the cells to 1 microM JMV 449 for 5 or 72 h, tyrosine hydroxylase protein and mRNA levels were significantly increased as detected by western blot analysis and quantitative RT-PCR, respectively. Transfection of CHP212 cells with a plasmid containing the luciferase reporter gene under the control of a limited proximal region of the cloned tyrosine hydroxylase promoter, revealed that the effect of JMV 449 results from an increase in the transcriptional activity of the TH gene. These results indicate that modulation of tyrosine hydroxylase gene expression may constitute one of the mechanisms involved in the control of dopamine transmission by neurotensin. Such neurotensin-mediated changes in tyrosine hydroxylase expression may also participate in multiple adaptation processes within the central nervous system to environmental conditions where neurotensin is released such as stress and food intake.

The advantages of bivalent hapten-bearing peptides for the detection of tumours pretargeted with bispecific antibodies have been demonstrated. This technology is now considered for radioimmunotherapy and bivalent haptens designed to target131I are needed. We thus synthesised a series of tyrosine-containing peptides bearing the histamine-hemisuccinate hapten. These molecules were tested for their ability to bind simultaneously two anti-hapten antibody molecules. One of these bivalent haptens, AG3.0, with a lysyl-d-tyrosyl-lysine connecting chain, was found to have optimal binding characteristics and was thus selected for further investigations. AG3.0 was shown to efficiently deliver radioactive iodine to human colorectal tumours grafted in nude mice using an anti-carcinoembryonic antigen×anti-histamine-hemisuccinate bispecific antibody. AG3.0 was also targeted to human B lymphoma cells pretargeted with a bispecific antibody specific for membrane IgM. In this system, bivalent ligands such as F(ab′)2 or IgG are rapidly internalised and covalently linked radioactive iodine is released from target cells as a result of intracellular catabolism. With the pretargeted iodine-labelled bivalent hapten, a fivefold increase in the intracellular activity retention time as compared to125I-labelled F(ab′)2 and IgG was observed. The radiolabelled hapten did not undergo any degradation after internalisation. These results have been confirmed in vivo with an anti-BCL1 IgM idiotype bispecific antibody and131I-labelled AG3.0. These reagents injected as a single 300 μCi dose, 7 days after inoculation of 104 BCL1 lymphoma cells in BALB/c mice, cured 14/16 of the animals and the treatment was well tolerated. Comparatively, the same dose of labelled IgG cured 13/16 of the mice but three mice died of haematologic toxicity. The same dose of labelled F(ab′)2 or Fab′ was completely inefficient.131I-labelled bivalent haptens are now used in phase I radioimmunotherapy clinical trials.

This study demonstrates the adhesion and growth of bovine corneal epithelial cells on the surface of a new hydrogel. The hydrogel, containing 78% of water and 22% of AN-69 polymer (poly(acrylonitrile-sodium methallyle sulfonate)), was obtained by phase inversion of polymer–dimethylformamide solution in physiological saline (0.9% NaCl). Experiments were also carried out using hydrogel treated with arginine, human albumin and collagen IV. Covering of hydrogel samples by epithelial cells was completed within ten days, with good cell viability. The epithelial cells spread out and formed a consistent cell layer, confirmed by immunocytochemistry experiments against cytokeratins. Transmission electron micrographs showed numerous desmosomes between cells and the presence of some membrane differentiations at the cell/hydrogel interface. This study suggests therefore that the hydrogel might be suitable for the development of artificial epikeratoplasty grafts.

An automated system, TRAKCELL, was developed for the quantitation of cells in culture. It enabled cell counting, classification according to morphological cell characteristics and measurement of cell proliferation and differentiation. The system was tested on the toxic effect of ascorbic acid on rat brain catecholaminergic neurons in primary culture. In parallel, the effects of nerve growth factor, dexamethasone and forskolin on cell differentiation were studied using rat pheochromocytoma PC12 cells. The results show that the system permits rapid and reproducible measurements of cell density and of the morphological changes observed following various drug treatments.

The localization of the messenger RNA (mRNA) encoding vasoactive intestinal peptide/peptide histidine isoleucine (VIP/PHI) in the rat eye was studied by in situ hybridization histochemistry using a synthetic 35S-labeled oligodeoxyribonucleotide. Among the layers of the retina, specific labeling was found in the soma of some cells in the innermost lamina of the inner nuclear layer. Occasionally, labeled cells were also present in the ganglion cell layer. No specific labeling was detected in any ocular structures other than the retina, including the cornea, iris, ciliary body, choroid, choriocapillaris, optic nerve and sclera. We also examined VIP/PHI mRNA expression in the suprachiasmatic nucleus (SCN) of the hypothalamus, which is the pacemaker of circadian rhythms and synchronizes them with the environmental light-dark cycle. High labeling was found in the ventrolateral part of the nucleus, which is the site of most projections from the retina. Monocular enucleation of rats at birth resulted in an increase of VIP/PHI mRNA expression in SCN ipsilateral to the removed eye after postnatal day 60. The discrete pattern of hybridization for VIP/PHI mRNA indicates that these two peptides are synthetized in rat retina and SCN and suggests that they may play a key role in the photic entrainment to the SCN regulating various circadian rhythms.

Vasoactive intestinal peptide (VIP) can be released in vitro from intestinal slices under veratridine and batrachotoxin depolarization, whereas potassium depolarization has no effect. The lack of an effect of potassium observed in this peripheral preparation is different from the positive action described for it in the CNS. The present data suggest that VIP can be released through different mechanisms in the peripheral and central nervous system.