Synaptic depression at type B to A photoreceptor connections in Hermissenda.
We quantified synaptic depression at the type B to A photoreceptor connections of Hermissenda. Type B cell action potentials were evoked at interstimulus intervals (ISIs) of 0.3, 3 or 30 s and the resulting inhibitory postsynaptic potentials (IPSPs) were recorded in a type A cell. A progressive decline in IPSP amplitude occurred at all three ISIs. Synaptic depression was greater at shorter ISIs, as was the level of recovery 2 min after the stimulus series. The profound level of synaptic depression observed (79.0+/-3.2% at the 0.3 s ISI) implies that synaptic depression is an important control process in the neuronal circuitry that drives phototactic behavior.
Schultz
L M
LM
Department of Psychology, Princeton University, NJ 08544, USA.
Lee
E S
ES
Clark
G A
GA
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D008564:Membrane Potentials / Q000502:physiology; D008974:Mollusca; D009434:Neural Pathways / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D017956:Photoreceptor Cells, Invertebrate / Q000502:physiology*; D013569:Synapses / Q000502:physiology*