Abstract
Serotonin (5-HT) perfusion of a thin section of Limulus lateral eye hyperpolarizes retinular and eccentric cell membrane potential, and blocks spike action potentials fired by the eccenteric cell. The indoleamine does not directly affect retinular cell receptor potential or eccenteric cell generator potential in response to light stimuli. LSD perfusion blocks both this inhibitory action of 5-HT and light- evoked, synaptically mediated, lateral inhibition. Iontophoretic application of 5-HT to the synaptic neuropil produces shorter latency and duration and larger amplitude of inhibition than does the perfusion technique. This inhibition is dose dependent; the accompanying inhibitory postsynaptic potential (IPSP) appears to have an equilibrium potential more hyperpolarized than normal resting potential levels of ca. -50 mV. IPSP amplitude is sensitive to extracellular potassium ion concentration: it increases with decreased [K+]0 and decreases with increased [K+]0. LSD blocks the inhibition produced by iontophoretic application of 5-HT. Interaction between light-evoked, natural synaptic transmitter-mediated IPSP's and 5-HT IPSP's suggests a common postsynaptic receptor or transmitter-receptor-permeability change mechanism.
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Selected References
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- Adolph A. R. Thermal sensitivity of lateral inhibition in Limulus eye. J Gen Physiol. 1973 Oct;62(4):392–406. doi: 10.1085/jgp.62.4.392. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Adolph A. R., Tuan F. J. Serotonin and inhibition in Limulus lateral eye. J Gen Physiol. 1972 Dec;60(6):679–697. doi: 10.1085/jgp.60.6.679. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Adolph A., Ehinger B. Indoleamines and the eccentric cells of the limulus lateral eye. Cell Tissue Res. 1975 Nov 17;163(1):1–14. doi: 10.1007/BF00218587. [DOI] [PubMed] [Google Scholar]
- Aghajanian G. K., Haigler H. J., Bloom F. E. Lysergic acid diethylamide and serotonin: direct actions on serotonin-containing neurons in rat brain. Life Sci I. 1972 Jul 1;11(13):615–622. doi: 10.1016/0024-3205(72)90153-1. [DOI] [PubMed] [Google Scholar]
- Bradley P. B., Candy J. M. Iontophoretic release of acetylcholine, noradrenaline, 5-hydroxytryptamine and D-lysergic acid diethylamide from micropipettes. Br J Pharmacol. 1970 Oct;40(2):194–201. doi: 10.1111/j.1476-5381.1970.tb09913.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown A. M., Sutton R. B., Walker J. L., Jr Increased chloride conductance as the proximate cause of hydrogen ion concentration effects in Aplysia neurons. J Gen Physiol. 1970 Nov;56(5):559–582. doi: 10.1085/jgp.56.5.559. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown J. E., Mote M. I. Ionic dependence of reversal voltage of the light response in Limulus ventral photoreceptors. J Gen Physiol. 1974 Mar;63(3):337–350. doi: 10.1085/jgp.63.3.337. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fahrenbach W. H. The morphology of the eyes of Limulus. II. Ommatidia of the compound eye. Z Zellforsch Mikrosk Anat. 1969;93(4):451–483. doi: 10.1007/BF00338531. [DOI] [PubMed] [Google Scholar]
- Gerschenfeld H. M. Chemical transmission in invertebrate central nervous systems and neuromuscular junctions. Physiol Rev. 1973 Jan;53(1):1–119. doi: 10.1152/physrev.1973.53.1.1. [DOI] [PubMed] [Google Scholar]
- Gur M., Purple R. L., Whitehead R. Ultrastructure within the lateral plexus of the Limulus eye. J Gen Physiol. 1972 Mar;59(3):285–304. doi: 10.1085/jgp.59.3.285. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kehoe J. Ionic mechanisms of a two-component cholinergic inhibition in Aplysia neurones. J Physiol. 1972 Aug;225(1):85–114. doi: 10.1113/jphysiol.1972.sp009930. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wolbarsht M. L., Yeandle S. S. Visual processes in the Limulus eye. Annu Rev Physiol. 1967;29:513–542. doi: 10.1146/annurev.ph.29.030167.002501. [DOI] [PubMed] [Google Scholar]