Photically evoked unit activity in the tectum opticum of the squirrel monkey

Abstract

Visually evoked unit responses of the tectum were studied in the squirrel monkey. The results showed that the superior colliculus had a definite functional laminar organization. Units responding to diffuse light were found in the upper part of the stratum grineum superficiale, units having antagonistically segregated receptive fields in the middle portion, and units sensitive to moving objects in the lower portion as well as in the stratum opticum. Retinotopic projection was also observed. The pretectal region contained mainly "tonic-on" and "inhibitory" units. No specific localization was observed in the distribution of these units.

Colour and pattern selectivity of receptive fields in superior colliculus of marmoset monkeys

“…Rapid habituation in responses of SC neurones has been noted previously (Horn & Hill, 1966; Kadoya et al 1971; Marrocco & Li, 1977); such behaviour is effectively absent from LGN populations measured in our and other laboratories. Similarly, very few retinal and LGN neurones exhibit complete bandpass spatial frequency selectivity.…”

Visual Receptive-field Properties of Single Cells in the Rat Superior Colliculus

“…The cells responding only to moving stimuli are not seen in the dorsally located group (I-, II-and III-cells). This has been reported for the SC as well as for the optic tectum; rat (HUMPHERY, 1968), mouse (DRAGER and HUBEL, 1975), golden hamster (TIAO and BLAKEMORE, 1976), cat (STERLING and WICKELGREN, 1969;STRASCHILL and HOFFMANN, 1969), rabbit (MASLAND et al, 1971), monkey (HUMPHERY, 1968;KADOYA et al, 1971), and pigeon (HUGHES and PEARLMAN, 1974;JASSIK-GERSCHEN-FELD and GUICHARD, 1972). Fourth, the maintained activity level is higher in the ventrally located cells (IIIb-and IV-cells) than the dorsally located ones (I-, II-and IIIa-cells).…”

“…Although it is thus considered as one of the most suitable subjects for functional studies of the SC, no extensive experiments have so far been made using electrophysiological techniques. Therefore, our knowledge of the SC function in the rat, particularly that based on single unit analysis, is insufficient (HUM-PHERY, 1968;SEFTON, 1969;SIMINOFF et al, 1966) when compared to information on the cat (DREHER and HOFFMANN, 1973;HOFFMANN, 1973;MCILWAIN and BUSER, 1968;STERLING and WICKELGREN, 1969;STRASCHILL and TAGHAVY, 1967;STRAS-CHILL and HOFFMANN, 1969) and monkey (CYNADER and BERMAN, 1972;KADOYA et al, 1971 ;UPDYKE, 1974). In view of this and being encouraged by a recent morphological study of LANGER and LUND (1974) and other similar ones (LABRIOLA and LAEMLE, 1977;TOKUNAGA and OTANI, 1976), the present series of experiments were initiated to provide a more detailed information on electrophysiological properties of the rat SC.…”

Pulvinar and other subcortical connections of dorsolateral visual cortex in monkeys

“…Thus, DL/MT C projections to the superior colliculus are deeper than projections from the retina, V1, and V2, but not as deep as projections from IT cortex, parietal cortex, and the frontal eye field (for review, see Cusick, 1988;Steele and Weller, 1993). Because practically all injections in DL/MT C were in regions representing the central to paracentral lower visual field, it was not surprising that label in the superior colliculus was in its central to lateral portions, which represent the lower field, and was in its anterior to middle levels, which represent the central to paracentral visual field (Kadoya et al, 1971;Cynader and Berman, 1972;Lane et al, 1973). However, the upper field injection in ventral MT C in OM-6 produced label in the caudal portion of the central to medial superior colliculus, which represents the paracentral to peripheral upper visual field.…”