Spatial and temporal integration properties of units in first optic ganglion of dipterans.

On-off units in the first optic chiasm of the blowfly II. Spatial properties

“…There is not variation in response shape over the receptive field. These results agree with the results obtained by Arnett on the dark-adapted eye of the fly Phaenicia sericata (Arnett 1971(Arnett , 1972. Seconly, we found that the half-width of the line spread function of the unit (calculated from its response to moving sinusoidal gratings) is somewhat broader than that of the photoreceptor, indicating some spatial smoothing.…”

“…The other neuron, the sustaining unit, was also silent in the dark, but produced a steady spike train to steady illumination. On the basis of lesion experiments, Arnett (1972) concluded that both units transmit spikes centripetally, i.e. from lamina to medulla.…”

Fast temporal adaptation of on-off units in the first optic chiasm of the blowfly

“…About 20 years ago Arnett (1971Arnett ( , 1972 and McCann and Arnett (1972) reported on two spiking units in the chiasm between lamina and medulla in the fly brain. One of these neurons, the on-off unit, produces a transient response when a light is switched on or off in its receptive field.…”

“…Its spike rate increases with light intensity, and it has two inhibitory regions flanking the central, excitatory region. On the basis of lesion experiments (Arnett 1972), both on-off and sustaining units are believed to carry spikes from lamina to medulla (centripetally). The on-off and sustaining units might correspond to lamina neurons L5 and L4, respectively (see Shaw 1981, and Laughlin 1981, 1984 for discussions).…”

What does the honeybee see? And how do we know? : A critique of scientific reason

“…Small spiking units were recorded below the lamina of the fly, with a centre 'on' and an inhibitory zone on either side (Arnett 1972), suggesting an early stage of motion detection there. Recently, lamina tangential dendrites sensitive to flicker but not motion were found, while another efferent neuron, C2, was sensitive to motion in either horizontal direction (Douglass and Strausfeld 1995-96).…”