Control of choroidal blood flow by the nucleus of Edinger-Westphal in pigeons: a laser Doppler study.

Anatomical studies in birds have suggested that choroidal blood flow may be regulated by a circuit involving the following serially-connected components: the retina-the suprachiasmatic nucleus (SCN)-the medial subdivision of the nucleus of Edinger-Westphal (mEW)-the ciliary ganglion-the choroidal blood vessels. In order to better clarify the role of this circuit, we examined the effects of electrical stimulation of EW on choroidal blood flow in the ipsilateral eye, using laser Doppler velocimetry to monitor choroidal blood flow in the superior pole of the eye. Baseline choroidal blood flow values (144-311.

Evidence for retinal pathology following interruption of neural regulation of choroidal blood flow: Müller cells express GFAP following lesions of the nucleus of Edinger-Westphal in pigeons.

Choroidal blood flow in pigeons is regulated by the medial part of the nucleus of Edinger-Westphal (EW) via the ipsilateral ciliary ganglion. Interruption of this circuit by unilateral lesions of EW results in pathological modifications in the morphology of retinal photoreceptors in the ipsilateral eye in pigeons housed under 12hr light (400 lux)/12hr dark conditions. In the present study, we examined the effects of unilateral EW lesions on glial fibrillary acidic protein (GFAP) expression by retinal Müller cells in pigeons housed under the same lighting conditions.

Kinetics of growth inhibition in a neoplastic population after repeated cytostatic treatment.

The analysis of growth kinetics of a neoplastic population after cytostatic treatment (radiation, chemotherapy) has been modeled by means of the cell cycle transition probabilities mu and transition intensities lambda. The transition between phases of the cell cycle and quiescent G0 cells during repeated cytostatic treatment has been exposed by the probabilistic model on the basis of the experimental data. The cytostatic treatment (the most effective time, dose and therapeutic combination) can be scheduled using established size and volume of the tumor and an estimate of cell proportion in various compartments of the neoplastic population.