This paper will describe the implementation of a 3D film method for achieving full resolution autostereoscopic 3D displays in handheld and portable devices. The three components of this technology ‐ a directional backlight, 3D Film and a 120Hz LCD panel ‐ will be described. Modeling and experimental device performance using OCB LCD panels will be reviewed along with 3D visualization performance.

A previous study demonstrated that the threshold dose of intra-arterial angiotensin II required to induce a pressor response in the rat was significantly lower when the drug was administered into the carotid artery than when administered into the abdominal aorta. This result was interpreted to indicate that part of the increase in arterial pressure produced by low concentrations of blood-borne angiotensin in this species was the result of an effect on structures in the central nervous system selectively accessible via the carotid vascular bed. The purpose of the present study was to establish more precisely the site of the pressor action of angiotensin within the central nervous system. The central component of the pressor effect of angiotensin was quantified as the difference in pressor responses to intracarotid and intra-aortic infusions of angiotensin II (delta c-a). In conscious rats, delta c-a was attenuated by administration of the angiotensin antagonist, saralasin, into the third cerebral ventricle. In rats with chronic electrolytic lesions of the anteroventral third ventricle (AV3V), delta c-a was abolished. Periventricular structures surrounding the third ventricle appear to mediate the central component of the pressor action of blood-borne angiotensin in the rat.

The purpose of this study was to determine if once-daily arterial pressure measurements are a reliable estimate of actual time-averaged arterial pressure in neurogenic hypertensive rats. Male rats were subjected to either aortic baroreceptor deafferentation (ABD, n = 10) or sham operation (SO, n = 10). One to 3 mo later, arterial pressure (AP) was recorded from a chronic indwelling catheter in each rat for 72 continuous hours. Subsequently, AP was determined once a day (10- to 30-min recording periods) in each rat for an additional 3 consecutive days. Continuous recording yielded an average mean arterial pressure (MAP) of 104 +/- 2 mmHg in SO rats and an average mean MAP of 120 +/- 3 mmHg in ABD rats. Standard deviation of MAP measured every 5 min for 24 consecutive hours (as an index of pressure lability) was 8.0 +/- 0.4 mmHg in SO rats and 14.4 +/- 1.3 mmHg in ABD rats. Both of the above differences were statistically significant (P less than 0.05). The average MAP from daily measurements in the same rats was 107 +/- 3 mmHg in SO rats and 124 +/- 3 mmHg in ABD rats. Average pressure values were not statistically different for the two measurement techniques in either group of rats. Overall, there existed a significant correlation (r = 0.64, P less than 0.01) between MAP measured continuously and daily in the 20 rats studied. We conclude that daily direct measurement of MAP in conscious ABD rats yields a satisfactory estimate of actual time-averaged MAP in these rats despite their markedly increased MAP lability.

SUMMARYIn an attempt to produce a form of chronic neorogenlc hypertension without the Increased blood pressure lability which b characteristic of total baroreceptor removal, selective aortic baroreceptor deafferentation (ABD) was performed In rats. Blood pressure, Mood pressure variability, heart rate, plasma and extracellular fluid volumes, and the effect of total autonomk blockade were determined in male rats 1 month following ABD. Rats with ABD had significantly higher systolic, diastollc, and mean arterial blood pressures than did sham-operated animals, but the standard deviation of pressure measured repetitively over a 1-hour period was not significantly greater. Total autonomk blockade with atroplne, propranolol, and pnentolamine lowered blood pressure and heart rate to a similar level In ABD and sham-operated rats. Extracellular fluid volume was not different In the two groups of rats, but plasma volume was significantly lower in rats with ABD. Despite the overall reduction in plasma volume, there was a significant positive correlation between plasma volume and blood pressure In ABD rats; no such correlation was observed in sham-operated rats. It was concluded that ABD produces a mild, chronic hypertension in rats without marked pressure lability. Although the hypertension appears to be "neurogenic" In that it is abolished by autonomic blockade, volume factors also may contribute to the increased blood pressure. (Hypertension 2: 319-325, 1980) KEYWORDS • hypertension • autonomic nervous system • baroreceptors • plasma volumeT HE existence of a true "neurogenic" hypertension produced by attenuation of the high-pressure baroreflex arc is a matter of controversy. Although many early studies described a chronic hypertension following deafferentation of the carotid and aortic baroreceptors 1 " 1 (referred to here as total baroreceptor denervation), the method used to measure arterial pressure may have been too stressful to allow accurate pressure determination. Recent studies 4 ' * using more sophisticated techniques of pressure measurement and data analysis indicated that total baroreceptor denervation greatly increases minute-to-minute blood pressure variability (lability), but only slightly increases the average blood pressure level. Other recent studies*"* using similar but not identical techniques, however, have shown that total baroreceptor removal (peripheral or central) will indeed produce a sustained arterial hypertension, albeit with increased pressure lability. In general, studies utilizing continuous (24 hr/day) pressure mea-

A small discrete area near the optic recess of the anterior ventral third ventricle (AV3V) in the rat brain has been shown to be an important mediator of cardiovascular and dipsogenic response to angiotensin II and osmotic stimuli and to be involved in normal day-to-day regulation of water and electrolyte balance. However, no attempt has been made until now to explore the function of the AV3V in species other than the rat. In the present study, rabbits subjected to electrolytic lesion of the AV3V exhibited expanded plasma volume and plasma sodium concentration, and significantly attenuated pressor responses to angiotensin II and hypertonic sodium chloride solutions injected via the lateral ventricles. Resting arterial pressure, plasma potassium concentration, extracellular fluid volume, and pressor responses to intravenous angiotensin II were not changed by lesioning. Thus, the effects of AV3V lesions in rabbits are similar, but not identical, to those previously observed in rats. Rabbits should be a suitable species in which to carry out studies aimed at distinguishing central and peripheral cardiovascular effects of angiotensin II.