title: Dissection of the neuron network in the catfish inner retina. I. Transmission to ganglion cells.
abstract: 1. To characterize the signal transmission from amacrine to ganglion cells, and to identify the filter that transforms amacrine-cell responses into ganglion-cell spike discharges, an extrinsic current, either sinusoidally or white-noise modulated, was injected into an amacrine cell and the resulting extracellular spike discharges were recorded from a neighboring ganglion cell. For the sinusoidal inputs, PST (poststimulus time) histograms were produced; for the white-noise inputs, first- and second-order Wiener kernels were computed by a cross-correlation process. 2. Extrinsic current injected either into a type-N (sustained) amacrine cell or a type-C (transient) amacrine cell modulated the spike discharges of nearby ganglion cells, whether of the "ON," "ON-OFF" or "OFF" types. We identified two modes of signal transmission, fast (probably monosynaptic) and slow (probably polysynaptic) transmission. Signal transmission from amacrine to ganglion cells of the same response polarity i.e., from type-NA (depolarizing, sustained) amacrine to ON-ganglion cell and from-NB (hyperpolarizing, sustained) amacrine to OFF-ganglion cell, was either fast or slow. Similarly, the signal transmission from type-C to either ON- or OFF-ganglion cells was either fast or slow. 3. The signal transmission from amacrine to ganglion cell of the opposite response polarity, i.e., from type-NA to OFF-ganglion cell and from type-NB to ON-ganglion cell, was always slow. 4. Fast transmission from type-N amacrine to a ganglion cell of the same polarity, or from type-C to either ON- or OFF-ganglion cells was always sign-noninverting. The transfer function was lowpass, with a cutoff frequency of 30 Hz. 5. Slow transmission from any type of amacrine cell (either type-NA, -NB or -C) to ON-ganglion cells was always sign inverting, whereas from any amacrine to OFF-ganglion cells was always sign-noninverting. The transfer function for the slow transmission was narrow bandpass, with a cutoff frequency of 30-40 Hz.
authors.affiliation: National Institute for Basic Biology, Okazaki, Japan.
authors.forename: H M
authors.initials: HM
authors.lastname: Sakai
authors.forename: K
authors.initials: K
authors.lastname: Naka
mesh_terms: D000200:Action Potentials; D000818:Animals; D001339:Autonomic Fibers, Preganglionic / Q000502:physiology; D002397:Catfishes / Q000502:physiology*; D002450:Cell Communication; D004558:Electric Stimulation; D005583:Fourier Analysis; D007059:Ictaluridae / Q000502:physiology*; D007395:Interneurons / Q000145:classification / Q000502:physiology; D009415:Nerve Net / Q000502:physiology*; D009424:Nervous System Physiological Phenomena; D012160:Retina / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000145:classification / Q000502:physiology*; D013569:Synapses; D009435:Synaptic Transmission