Figures

Chapter 4

Fig. 4 1. My UCLA real time digital programmer and digital computer (many peripheral components not shown).

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Fig. 4-2. Hourly activity profile for deer mouse in running wheel enclosure (see Figs. 2-11 & 2-12) for one adapted week each on one-factor (blocks) and 2-factor (bars) programs. On the 1-factor program: to obtain a food pellet, a switch had to be pressed; to drink, a water shutter had to be brushed aside; to leave the nest, a shutter had to be brushed aside; all other activities were at will. On the 2-factor program: to obtain a food pellet, two switches had to be pressed in proper sequence; to drink, a switch had to be pressed to unlock the water shutter for 3 sec.; to leave the nest, a switch had to be pressed to unlock the shutter; to run the wheel, a switch had to be pressed, which unlocked it for 5 min. The mouse ran both more (50% more revolutions) and 40% faster on the 2-factor program, even though it had to unlock the wheel again every 5 min.

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Fig. 4-3. Wheel-running record of deer mouse of Fig. 4-2 on 2nd night of one-factor program (a) and 3rd night of 2-factor program (b). Each point represents the instantaneous time, rate (rpm) and direction (CW above, CCW below) of running, printed at 2-sec intervals. (a) free-wheeling running showing an extended 'warm-up' and sustained reversal of direction. (b) successive 5-min sessions of running with a brief 'warm-up,' sustained running at maximum speed, and illustrating a remarkable instance of goal-directed lever-pressing (to unlock the wheel and run in it for 5 min every 5 min).

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Fig. 4-4. Models of countercurrent streaming on an inclined plate tilted a few degrees from horizontal, as tap water from a nozzle (top) flows down it into a reservoir (bottom). Flow of both the surface film and interior stream can be visualized with powdered charcoal. The arrows indicate flow of the surface film, only, all of which is upward. All interior flow is downward. The apparent downward flow of some regions of the surface film is an illusion, created by its being dragged downward at different rates by the interior stream. In C, there is no interior flow in the uppermost loop. In essence, differences in surface tension between fresh water from the nozzle and aged water in the reservoir are responsible for the different film and stream flow rates.

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Fig. 4 5. At left, proposed pillar to disc biological membrane transformation. Hexagonal arrays of lipoprotein pillars in the open configuration (a) at the top (hypothetically seen from above in Fig. 4-5 (right), transform (b to e) to discs in the closed configuration at the bottom. At right, electron micrograph of negatively stained, saponin damaged plasma membranes of chick liver cells in the proposed open configuration, showing ends of hexagonally distributed pillars.

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Fig. 4-6 (above, upper left). Wheel running record of a female deer mouse during a night with simulated twilights. Time, speed, and direction of running are given by the dots at 4-sec intervals. Note, there is no 'warm-up' during dusk (indicated by downward sloping arrow), rather the animal begins at high speed during middle-to-late dusk, also terminating at high speed during mid dawn (indicated by upward-sloping arrow). During the night hours in dim overhead light, running is more-or-less sustained, speed is maintained at roughly 50 rpm, and running direction is almost exclusively CW.

Fig. 4-7 (above, right). Revolutions run per _-hr by the same mouse of Fig. 4-6 plotted on 24-hr grid on the following programs. With the animal already adapted to 22 24-hr days of light:dim (16:8) with simulated twilights, dusks were advanced 1, 2, 3, and 4 hrs on the 1st, 3rd, 5th, and 7th days. The cumulative shift of 10-hr was closely followed. Subsequent 16-hr periodicities of light:dim (8:8) and (10:6) also were followed. After 22 of these 16-hr cycles, constant dim light was presented after the last dusk. The animal responded with a 10-hr phase shift, returning to an endogenous 24-hr cycle but with two major activity periods per cycle. The animal failed to sustain continuous nocturnal running on only six of the 22 16-hr cycles.

Fig. 4-8 (above, lower left). Plots for 11 16-hr cycles of wheel-running, time in nest, and water consumption of the same mouse used in the studies of Fig 4-6, placed directly on a 16-hr regime of light:dim (9:7) with simulated twilights, without prior adaptation. By the 4th cycle, running activity (plotted for _-hr intervals; below, but for 10-min intervals, above, during twilight hours) followed the regime closely. Plots of time in nest, water consumption, and food consumption (not shown) displayed clear-cut 16-hr rhythmicities in phase with the light cycle. The central bars for time in nest and water give the number of drinks and nest entrances and exits (right ordinate scales). It is noteworthy that the mouse never left the nest in the 2 hours immediately following dawn (second plot from bottom). Downward slanting arrows indicate dusk; upward slanted arrows indicate dawn.

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