Purpose The effects of astaxanthin (Ax) on the in vitro development of bovine embryos cultured under heat stress were investigated in combination with the assessment of its cellular accumulation and action on mitochondrial membrane potential (Δ

Summary The behavioral changes of the unrestrained cat elicited by the square pulse stimulation through the bipolar electrode implanted in the various portions of the brain stem, mainly in the midline, were investigated, and the points of stimulation were later ascertained histologically. The results of the study are summarized as follows: (1) The arrest reaction was elicited from the midline areas extending from the rostral part of the thalamus as far as to the caudal part of the medulla oblongata, especially from the midline of the mesencephalic reticular formation, by means of the various stimuli. (2) The arrest reaction that could be elicited from the reticular formation between decussatio tractuum tegmenti and decussatio brachiorum conjunctivorum at the level of nucl. oculomotorii in the midbrain was utmost typical and most easily inducible. (3) To elicit the arrest reaction from the midbrain and the more caudal brain stem, 60 to 100 cps, 2 to 5 v, 0.2 msec were found the most adequate. In the thalamus, slightly higher intensity seemed necessary to induce the arrest reaction. (4) During the arrest reaction the postural and nociceptive reflexes were preserved, though diminished and insufficient. (5) The chief findings of the ECG were: a) By the appropriate stimulation of the arrest areas, synchronous large waves much resembling the recruiting response were recorded, and b) In cases where the arrest reaction took place most typical, the preexisting spontaneous discharges (about 3 to 5 cps) tended to be blocked. (6) According to the findings of the EMG, the arrest reaction represents an inhibition in the descending direction. (7) Stimulation of other portions of the brain stem with the routine intensity or stimulation of arrest areas with the higher intensity elicited the general activation, specific movements or convulsions, etc.

No abstract