Intracellular calcium signals are enhanced for days after Pavlovian conditioning.
Previous observations have implicated GABA as a neurotransmitter released by the vestibular sensory neurons ("hair cells") of the snail Hermissenda onto visual sensory neurons, the type B cells, whose cell bodies are the sites of biophysical and biochemical changes during and following Pavlovian conditioning. Still other observations demonstrated that light-GABA pairings that simulate stimuli presented during Pavlovian conditioning cause prolonged elevation of intracellular Ca2+ and transformation of GABA-induced synaptic inhibition into excitation. Intracellular Ca2+ signals in response to GABA perfused onto the postsynaptic type B terminal branches are shown here to be prolonged on days after conditioning, but not after control paradigms. These and past results demonstrate two separate sites, i.e., the cell body and the terminal branches, for learning-induced changes after Pavlovian conditioning.
Ito
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Laboratory of Adaptive Systems, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
Oka
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K
Collin
C
C
Schreurs
B G
BG
Sakakibara
M
M
Alkon
D L
DL
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003214:Conditioning, Classical / Q000502:physiology*; D005456:Fluorescent Dyes; D016257:Fura-2; D008027:Light; D008839:Microelectrodes; D009475:Neurons, Afferent / Q000502:physiology; D017956:Photoreceptor Cells, Invertebrate / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D012908:Snails / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology / Q000502:physiology
D005456:Fluorescent Dyes; D005680:gamma-Aminobutyric Acid; D002118:Calcium; D016257:Fura-2