Intraventricular melanin-concentrating hormone stimulates water intake independent of food intake

The lateral hypothalamus (LH) has a critical role in the control of feeding and drinking. Melanin-concentrating hormone (MCH) is an orexigenic peptidergic neurotransmitter produced primarily in the LH, and agouti-related protein (AgRP) is an orexigenic peptidergic neurotransmitter produced exclusively in the arcuate (ARC), an area that innervates the LH. We assessed drinking and eating after third ventricular (i3vt) administration of MCH and AgRP. MCH (2.5, 5, and 10 μg i3vt) significantly increased food as well as water intake over 4 h when administered during either the light or the dark portion of the day-night cycle. When MCH (5 μg) was administered to rats with access to water but no food, they drank significantly more water than when given the vehicle. AgRP (7 μg i3vt), on the other hand, increased water intake but only in proportion to food intake during the dark and the light, and water intake was not increased after i3vt AgRP in the absence of food. Hence, in contrast to AgRP, MCH elicits increased water intake independent of food intake. These results are consistent with historical data linking activity of the LH with water as well as food intake.

Taiwan Oscillation Network and Small-Telescope Research at Tsing Hua University

Two projects, the Taiwan Oscillation Network (TON) project and the earthshine project, at Tsing Hua University will be discussed. The TON is a ground-based network to measure solar intensity oscillations to study the solar interior. Four telescopes have been installed in Tenerife (Spain), Big Bear (USA), Huairou (PRC), and Tashkent (Uzbekistan). The recent scientific results from the TON data will be briefly discussed. The earthshine project is to measure the brightness of the dark portion of the lunar disk to obtain the Earth’s global albedo. The dark portion of the Moon is lit by the sunlight reflected from the Earth. The global albedo is linked to the global temperature of the Earth. The long-term measurement of earthshine will provide information on the long-term variation of the global temperature. An automated earthshine telescope is being developed at Tsing Hua University. It will be installed at Lulin Mountain in central Taiwan. The ultimate goal is to build a ground-based global network to measure the long-term variation of earthshine to learn about the long-term variation of the global temperature.

Influence of spinal and hypothalamic warming on metabolism and sleep in pigeons

Animals were prepared with electrooculogram (EOG), cortical electroencephalogram (EEG), and electromyogram (EMG) electrodes and with spinal and/or hypothalamic thermodes. Experiments were run at a cold and a neutral ambient temperature (Ta) during the dark portion of a 24-h light-dark cycle. Metabolic rate, temperatures, EEG, EMG, and EOG were measured continuously for 4-h periods with hypothalamic or spinal temperature unmanipulated or warmed to the level measured during the light. The cold Ta increased metabolic rate over the neutral Ta, but did not influence total sleep time (TST) or rapid-eye-movement sleep (REM) as percent TST. At the cold Ta, spinal warming resulted in reduction in REM as a percent TST. Spinal warming frequently caused a fall in body temperature (Ta). A plot of REM as a percent TST vs. the fall in Tb, including data for all animals and all conditions, revealed a clear correlation between fall in Tb and reduction in REM. Hypothalamic warming had no influence on metabolic rate, Tb, or distributions of arousal states. Cold thermal stimuli caused by a fall in Tb can inhibit REM in birds as it can in mammals independently of thermoregulatory drive.

Illumination Preference of Albino Rats in a Closed Hexagonal Maze

Ss were allowed to choose among 6 illumination conditions by altering their location in a maze. For a choice among 0 (darkness), 1, 2, 4, 8, and 16 ft.-candles in Exp. 1, preference decreased with increasing intensities. Ss tested during the dark portion of their cycle showed a stronger preference for darkness than Ss tested during the lighted portion of their cycle. In Exp. 2, preference for 0, .01, .1, 1.0, 10.0, and 25.0 ft.-candles was again inversely related to intensity, except that there was no difference between preference for darkness and .01 ft.-candles.

Selecting the Moon's Limb

This paper describes two methods of determining whether a sextant observation of the Moon should be of the upper or lower limb. The first method requires the use of a celestial globe or planisphere; the second is mathematical and requires a certain amount of computation, but is exact.The line which separates the dark portion of the Moon's disk from the illuminated portion is known as the terminator, and the straight line joining the ends of the terminator is that used in this problem. This line is always perpendicular to a line from the Moon to the Sun (the horns being always turned away from the Sun), so that its position can be predicted from the geometrical relations of the Earth, Sun and Moon. This enables the limb to observe to be determined.

A NEW LASIOCAMPID FROM ARIZONA

Eutricha Oweni, n. sp., ♂.— Expanse, 70 mm. Thorax, abdomen and fore wings reddish-brown, more or less lightened from an admixture of pale gray or whitish scales or hairs. Fore wings crossed by four lines, one at inner fourth dark reddish-brown, accompanied by a pale inner line, almost transverse, only slightly incurved at costa and inner margin. The dark portion of the line is well marked, the paler portion not so distinct.