The region of vibrissae representation in the ventrobasal complex (VB) of the rat was systematically mapped, based on receptive fields of many single neurons. Results showed that the ventralmost row of vibrissae projected to the rostral part of VB, that the dorsal-most row projected to the caudal part, and that the caudalmost vibrissae of each row projected to the most dorsolateral part of VB and more rostral vibrissae to the more ventromedial part. Further, it was revealed that the clusters of neurons receiving projections from any individual vibrissae formed corresponding columns extending from the anterodorsomedial to the posteroventrolateral direction, and that these columns piled up dorsoventrally and anteroposteriorly, with ventral ones shifted progressively medially. When cross sections of these columns were viewed on an oblique horizontal section of VB, a group of columns corresponding to each row lined up from the dorsolateral to the ventromedial direction with a rostral convexity, which means that the third or fourth vibrissa in each row projected most rostrally in that row. These results confirmed previous physiological mapping studies of vibrissal representation and are in good agreement with anatomical studies on barreloid structure in VB.

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Godet, J., D. Schiirch and V. Nigon, 1970b. Caracterisation et evolution des hemoglobines dans le cours du developpement postembryonnaire chez la poule. J. Embry. Exp. Morph. 23: 153-167. Konitzer, K., and K. Michalke, 1965. Der eisenstoffweschel der weissen Mous Ausscheichung und organ verterlung einen Fe 59 tracer dosis. Acta Biol. Med. Germ. 14: 489-495. Ramsay, W. N. M., 1966. The incorporation of iron into hemoglobin in the domestic fowl. Quat. J. Exp. Physiol. 51: 221-228. Rusov, C, 1965. Recherches sur la ferrocinetique des volailles normales par Fe 59 . Med. Landbow. Opzechugs Genet. 30: 787-795. ABSTRACTEffects of different photoperiods on the appearance of EEG slow waves were examined in freely-moving chickens by a radio telemetry system. The experiments were performed under 14L10D, 18L6D, 21L3D and 24L. It was clear that the EEG components were strictly synchronized to light-dark cycles. Continuous illumination exerted a dampening effect on the appearance of the slow wave diurnal rhythms. Chickens exposed to light-dark cycles of 14L10D and 18L6D maintained a constant daily level of slow wave activity. These levels are regarded as a normal amount of slow wave activity in male chickens. The daily amount of slow wave activity under 21L3D and 24L is probably regulated in a way different from that under 14L10D and 18L6D. The illumination seems to exert a strong effect on the mechanism controlling the appearance of the EEG in chickens when compared to mammals.

The electroencephalogram (EEG) of the chicken hypothalamus was recorded under the influence of repetitive photic stimulation, while thyroid activity was assessed by determining blood protein bound ¹³¹I levels in sequential samples. EEG waves in regions examined were distinctly entrained with a flicker frequency. The blood PB ¹³¹I level was increased by 20 min photic stimulation of 3 cps and was decreased by 12 cps flicker, while 24 cps flicker exerted no effect on thyroid function.