Interaction Between Gustatory Depolarizing Receptor Potential and Efferent-Induced Slow Depolarizing Synaptic Potential in Frog Taste Cell

• Published in: Cellular and molecular neurobiology Vol. 29; no. 2; pp. 243 - 252
• Main Authors: Sato, Toshihide, Nishishita, Kazuhisa, Okada, Yukio, Toda, Kazuo
• Format: Journal Article
• Language: English
• Published: Boston Boston : Springer US 01.03.2009; Springer US
• Subjects: Action Potentials - physiology; Animals; Anura; Biomedical and Life Sciences; Biomedicine; Cell Biology; Efferent Pathways - physiology; Hypoxia - metabolism; Hypoxia - physiopathology; Medulla Oblongata - physiology; Neurobiology; Neurosciences; Original Paper; Oxygen Consumption - physiology; Rana catesbeiana; Sensory Receptor Cells - physiology; Sensory Receptor Cells - ultrastructure; Species Specificity; Synaptic Potentials - physiology; Taste - physiology; Taste Buds - cytology; Taste Buds - physiology; Tongue - cytology; Tongue - physiology; Visceral Afferents - physiology; Basic taste stimuli; Gustatory efferent synapse; Receptor potential; Frog taste cell; Slow depolarizing synaptic potential; Parasympathetic nerve
• ISSN: 0272-4340; 1573-6830; 1573-6830
• DOI: 10.1007/s10571-008-9317-7

Electrical stimulation of parasympathetic nerve (PSN) efferent fibers in the glossopharyngeal nerve induced a slow depolarizing synaptic potential (DSP) in frog taste cells under hypoxia. The objective of this study is to examine the interaction between a gustatory depolarizing receptor potential (GDRP) and a slow DSP. The amplitude of slow DSP added to a tastant-induced GDRP of 10 mV was suppressed to 60% of control slow DSPs for NaCl and acetic acid stimulations, but to 20-30% for quinine-HCl (Q-HCl) and sucrose stimulations. On the other hand, when a GDRP was induced during a prolonged slow DSP, the amplitude of GDRPs induced by 1 M NaCl and 1 M sucrose was suppressed to 50% of controls, but that by 1 mM acetic acid and 10 mM Q-HCl unchanged. It is concluded that the interaction between GDRPs and efferent-induced slow DSPs in frog taste cells under hypoxia derives from the crosstalk between a gustatory receptor current across the receptive membrane and a slow depolarizing synaptic current across the proximal subsynaptic membrane of taste cells.