An analysis of the 5-hydroxytryptamine (serotonin) receptor subtypes of central neurones of Helix aspersa

Agnes Vehovszky, Robert J. Walker

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

1. Intracellular recordings were made from identified neurones in the central nervous system of Helix aspersa. Two types of cell were used, those excited by 5-hydroxytryptamine (5-HT) and acetylcholine and those inhibited by 5-HT and dopamine. The actions of a range of 5-HT agonists and antagonists were tested for their ability to interact with 5-HT receptors. 2. 5-Carboxyamidotryptamine, α-methyl-5-HT and N-methyl-5-HT were active on cells excited by 5-HT, with similar potencies to 5-HT. Only 5-carboxyamidotryptamine and 5-methoxytryptamine were equiactive with 5-HT on cells inhibited by 5-HT. Most of the non-indole analogues were inactive or very weak agonists on both receptors. 3. MDL 72222 was the most active antagonist tested against 5-HT excitation, showing some selectivity for 5-HT over acetylcholine. Cinanserin and ketanserin also showed selectivity for 5-HT over acetylcholine. 4. Tryptamine was inhibitory on both cell types and was a potent antagonist of 5-HT excitation, showing selectivity for 5-HT over acetylcholine. 5. It is concluded that the 5-HT excitatory receptor recognizes the indole nucleus with substitution on position 5, save for 5-fluorotryptamine which was inhibitory. It does not appear that these 5-HT receptors can be classified in terms of the vertebrate subtypes of 5-HT receptor. However, it should be noted that only two receptor subtypes located on a small number of neurones were studied in these experiments and other 5-HT receptor subtypes may be located on other groups of neurones and peripheral tissues. These receptors may recognize other 5-HT receptor ligands including non-indoles.

Original languageEnglish
Pages (from-to)463-476
Number of pages14
JournalComparative Biochemistry and Physiology. Part C, Comparative
Volume100
Issue number3
DOIs
Publication statusPublished - 1991

ASJC Scopus subject areas

  • Immunology
  • Pharmacology

Fingerprint Dive into the research topics of 'An analysis of the 5-hydroxytryptamine (serotonin) receptor subtypes of central neurones of Helix aspersa'. Together they form a unique fingerprint.

  • Cite this