Journal of Neuroscience, Vol 5, 2989-3009, Copyright © 1985 by Society for Neuroscience
Correlations between the structural and functional characteristics of neurons in the superficial laminae and the hamster's superior colliculus
RD Mooney, BG Klein and RW Rhoades
Intracellular recording, receptive field mapping, and horseradish
peroxidase (HRP) injection techniques were used to determine the structural
and functional characteristics of neurons in the superficial laminae
(stratum griseum superficiale and stratum opticum) of the hamster's
superior colliculus (SC). Fifty-nine neurons (from 38 different hamsters)
were successfully characterized, injected with HRP, and recovered. Of
these, 8 were marginal cells, 14 had stellate morphology, 10 had narrow,
vertically oriented dendritic trees, 12 had wide, vertically oriented
dendritic arbors, and 8 were horizontal cells. Seven neurons had
somatodendritic morphologies which did not fall into any of these groups.
Overall, the distribution of receptive field properties for these cells
matched that obtained in previous extracellular recordings from the
superficial SC laminae in this species (Chalupa, L.M., and R.W. Rhoades
(1977) J. Physiol. (Lond.) 270: 595-626; Chalupa, L.M. and R.W. Rhoades
(1978) J. Physiol. (Lond.) 274: 571-592). There were significant
correlations between receptive field properties and morphology. Sixty-four
percent of the stellate cells and 75% of the marginal cells were
directionally selective. Only 17% of the other cell types exhibited this
response property. In addition, only 36% of the stellate cells and 25% of
the marginal neurons were discharged by stationary, flashed spots.
Eighty-one percent of the other recovered cells gave reliable responses to
such stimuli. Stellate and marginal cells could also be differentiated from
the other cell types on the basis of speed selectivity. Only 29% of the
stellate and 13% of the marginal cells responded to stimulus speeds in
excess of 20 degrees/sec.(ABSTRACT TRUNCATED AT 250 WORDS)