Behavioral choice by presynaptic inhibition of tactile sensory terminals.
When presented with multiple stimuli, animals generally choose to respond only to one input. The neuronal mechanisms determining such behavioral choices are poorly understood. We found that the medicinal leech had greatly diminished responses to moderate mechanosensory input as it fed. Feeding dominated other responses by suppressing transmitter release from mechanosensory neurons onto all of their neuronal targets. The effects of feeding on synaptic transmission could be mimicked by serotonin. Furthermore, the serotonin antagonist mianserin blocked feeding-induced decreases in synaptic transmission. These results indicate that feeding predominates behaviors by using serotonin at an early stage of sensory processing, namely on presynaptic terminals of mechanosensory neurons.
Neurosciences Graduate Program, Division of Biological Sciences, University of California San Diego, La Jolla, California, USA.
Quentin
Q
Gaudry
William B
WB
Kristan
D000344:Afferent Pathways / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D002755:Choice Behavior / Q000502:physiology*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology; D017952:Ganglia, Invertebrate / Q000166:cytology; D066298:In Vitro Techniques; D007865:Leeches / Q000166:cytology; D008803:Mianserin / Q000494:pharmacology; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D010812:Physical Stimulation / Q000379:methods; D017729:Presynaptic Terminals / Q000187:drug effects / Q000502:physiology*; D011984:Sensory Receptor Cells / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D013550:Swimming / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D014110:Touch / Q000502:physiology*
D012702:Serotonin Antagonists; D008803:Mianserin; D012701:Serotonin