Downregulation of muscarinic- and 5-HT1B-mediated modulation of [3H]acetylcholine release in hippocampal slices of rats with fimbria-fornix lesions and intrahippocampal grafts of septal origin

Autor: Hélène Jeltsch, B. Szabo, Dorothee Lauth, B. Neufang, Jean-Christophe Cassel, Rolf Jackisch
Přispěvatelé: Laboratoire de neurosciences cognitives et adaptatives (LNCA), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), IFR de neurosciences de Strasbourg (INS), Université Louis Pasteur - Strasbourg I-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 1995
Předmět:
Atropine
Pyridines
Methiothepin
Physostigmine
[SDV]Life Sciences [q-bio]
[SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology
Nicotinic Antagonists
Mecamylamine
Hippocampus
Choline
Norepinephrine
0302 clinical medicine
Muscarinic acetylcholine receptor
ComputingMilieux_MISCELLANEOUS
Neurons
8-Hydroxy-2-(di-n-propylamino)tetralin
0303 health sciences
Chemistry
General Neuroscience
Hydroxyindoleacetic Acid
Receptors
Muscarinic
Serotonin Receptor Agonists
Cholinergic Fibers
Diffusion Chambers
Culture
Female
[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]
Serotonin Antagonists
Acetylcholine
medicine.drug
Serotonin
medicine.medical_specialty
Sciences du Vivant [q-bio]/Neurosciences [q-bio.NC]
Down-Regulation
Muscarinic Antagonists
Muscarinic Agonists
Tritium
Muscarinic agonist
Choline O-Acetyltransferase
03 medical and health sciences
Internal medicine
Oxotremorine
medicine
Animals
Brain Tissue Transplantation
Pyrroles
Molecular Biology
030304 developmental biology
CP-93129
Muscarinic antagonist
Rats
Inbred Strains
Electric Stimulation
Rats
Endocrinology
Receptors
Serotonin
Cholinergic
Septal Nuclei
Cholinesterase Inhibitors
Neurology (clinical)
030217 neurology & neurosurgery
Developmental Biology
Zdroj: Brain Research
Brain Research, Elsevier, 1995, 704 (2), pp.153-166. ⟨10.1016/0006-8993(95)01092-0⟩
ISSN: 0006-8993
DOI: 10.1016/0006-8993(95)01092-0
Popis: Adult Long-Evans female rats sustained electrolytic fimbria-fornix lesions and, two weeks later, received intrahippocampal suspension grafts of fetal septal tissue. Sham-operated and lesion-only rats served as controls. Between 6.5 and 8 months after grafting, both the [3H]choline accumulation and the electrically evoked [3H]acetylcholine ([3H]ACh) release were assessed in hippocampal slices. The release of [3H]ACh was measured in presence of atropine (muscarinic antagonist, 1 microM), physostigmine (acetylcholinesterase inhibitor, 0.1 microM), oxotremorine (muscarinic agonist, 0.01 microM-10 microM), mecamylamine (nicotinic antagonist, 10 microM), methiothepin (mixed 5-HT1/5-HT2 antagonist, 10 microM), 8-OH-DPAT (5-HT1A agonist, 1 microM), 2-methyl-serotonin (5-HT3 agonist, 1 microM) and CP 93129 (5-HT1B agonist, 0.1 microM-100 microM), or without any drug application as a control. In lesion-only rats, the specific accumulation of [3H]choline was reduced to 46% of normal and the release of [3H]ACh to 32% (nCi) and 43% (% of tissue tritium content). In the grafted rats, these parameters were significantly increased to 63%, 98% and 116% of control, respectively. Physostigmine reduced the evoked [3H]ACh release and was significantly more effective in grafted (-70%) than in sham-operated (-56%) or lesion-only (-54%) rats. When physostigmine was superfused throughout, mecamylamine had no effect. Conversely, atropine induced a significant increase of [3H]ACh release in all groups, but this increase was significantly larger in sham-operated rats (+209%) than in the other groups (lesioned: +80%; grafted: +117%). Oxotremorine dose-dependently decreased the [3H]ACh release, but in lesion-only rats, this effect was significantly lower than in sham-operated rats. Whatever group was considered, 8-OH-DPAT, methiothepin and 2-methyl-serotonin failed to induce any significant effect on [3H]ACh release. In contrast, CP 93129 dose-dependently decreased [3H]ACh release. This effect was significantly weaker in grafted rats than in the rats of the two other groups. Our data confirm that cholinergic terminals in the intact hippocampus possess inhibitory muscarinic autoreceptors and serotonin heteroreceptors of the 5-HT1B subtype. They also show that both types of receptors are still operative in the cholinergic terminals which survived the lesions and in the grafted cholinergic neurons. However, the muscarinic receptors in both lesioned and grafted rats, as well as the 5-HT1B receptors in grafted rats show a sensitivity which seems to be downregulated in comparison to that found in sham-operated rats. In the grafted rats, both types of downregulations might contribute to (or reflect) an increased cholinergic function that results from a reduction of the inhibitory tonus which ACh and serotonin exert at the level of the cholinergic terminal.
Databáze: OpenAIRE
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