Illinois Junior Academy of Science - Yearbook (Urbana, IL)

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The Effect of Temperature on Nerve Impulse Transmission ROBERT M. KAYE Niles North High School , Ii Ihetffpnon gggg Hmn5m,ss4QA 5 e 'W'df'1ffo... wffvf 5l ,mu amp? Dem miK 'fRfAnl sH1IIAlC'?5fUm. - V Lag poukataslgg . Inmglii , A , V ' , . - . It at T X AttimPizentiil,.asfunctWfIffHP A - - Ippmxtui I I ' .' I 'il . -L. This investigation is an attempt to relate the laws of thermodynamics to activity in biological systems. Specifically, it studies the effect of temperature on nerve impulse trans- mission and action potential. Based on the fact that the nervous system seems to regulate all body functions, it was hypothesized that the optimum temperature of these bio- chemical processes would indicate the optimum temperature of the organism as a whole. If this is the case, then behavior could be linked to environmental conditions. Apparatus was designed and constructed to test the reliability of the hypothesis. Frog sciatic nerves were elec- trically stimulated and observed with an oscilloscope. It was found that increases in temperature between 5.0 C and 25.5 C resulted in changes of the above factors according to Qi... Beyond 25.5 C transmission rate and action potential decreased. In analysis of transmission rate and action po- tential, both were found to have the same temperature of greatest activity. This optimum temperature was 25.5 C. Although the data shows the influence of thermody- namics as checked by QW, it cannot be soundly concluded that these are the prime factors in nerve transmission. Further, it cannot be safely deduced that these factors, as affected by temperature, are the significant variables in poikilother- mal behavior. Other research suggest the importance of absolute threshold. Further investigation must be done. months. My conclusion is that there are many differences between frogs and toads which are never seen or known by the average person. Frogs and Toads: What is The Difference? DAVID B. DUNN The purpose of this exhibit is to study and describe the principal characteristics of frogs and toads and to learn the differences between them. Outside assistance I received was help and counsel from my teacher, Mrs. Foard and typing by my parents. I read and studied resource materials listed in biblio- graphy. Accumulated and labeled preserved specimens. Col- lected and cared for live specimens in captivity for several months. My conclusion is that there are many differences between frogs and toads which are never seen or known by the average person. s, I I 1 DAVID MOLNNR n Pm-pose: The purpose of my experimentation is to in- vestigate and mathematically analyze some of the variables inyolved in the evaporation of ethyl alcohol. I am primarily concerned with temperature change and heat loss caused by the evaporation. Procedure: Sixty grams of ethyl alcohol is placed in a thermos bottle filler, a thermometer is inserted, and the whole apparatus is set upon a scale. A small fan is used to blow the vapors away, thereby speeding the evaporation, and a timer is used to keep track of the time since evapora- tion began. The alcohol is allowed to evaporate freely and the temperature and time are noted after every half gram of alcohol evaporates. The alcohol starts at room tempera- ture in each case. In the second phase of the project I at- tempt to reproduce the literature value for the latent heat of vaporization for ethyl alcohol by adding enough energy, electrically, to keep the temperature constant throughout evaporation. Results: The results are best summarized in the data tables which appear in the body of the report. Interpretation: My interpretation consisted primarily of an analysis of the data which resulted in four original equa- tions: 13 T 2 21.1 110-0-079 ml 23 T-6.8 I 15.5 C10-3-2810-401 35 c + 210 2 44.9 L0-344 41 c Z 235 tm-0.659 0-432 where T is the temperature in C., m is the total weight lost, t is the time in seconds since evaporation began, and c is the total number of calories lost. My problem has two parts. My first part is to learn what weather conditions affect the entry of box turtles into the ground for hibernation. The second part of my problem concerns whether their downward movement through the ground is related to weather conditions. I recorded the dates that the box turtles entered the ground in 1964 and 1965. In 1965 I also kept regular meas- urements of the box turtles downward movement. Then I got weather data on air temperatures, ground temperatures, precipitation and cloud cover and compared these with my turtle data. When I compared the data to the weather data I found

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some relationships that might explain the turtles entry and downward movement. I found that the turtles entered the ground a few days after the minimum air temperatures got. below 40 degrees. The minimum air temperatures in 1964 and 1965 appeared to follow a similar pattern in the 3 weeks prior to the entry. Precipitation also occurred 1 day before the turtles entered the ground. ' I found that the turtles downward movement was rela- tively' slow and constant until the soil temperatures fell rapidly. Thus, the speed of the turtles dovsmward motion apparently is related to temperatures. 1' ATIQN or max f1,W+,iyrHr:.lz Body Function Changes in Lizards at Various Temperatures HILLARD L CHEMERS lay Rogers Elementary School Chicago Sponsor: Mr. Alvin Blackman The body functions being measured in this project are metabolism, oxygen consumption, heartbeat, and body tem- perature. The collared lizard is the test animal being used for the experiments. The test animals were placed in a specially designed ap- paratus. For measuring metabolism and oxygen consumption the amounts of water vapor and carbon dioxide exhaled by the lizard during the test are weighed. The weights are put through various formulae and the answer is -found. Heart- beat is measured on an electrocardiograph obtained on loan from the manufacturer for this purpose. Twenty-five guage hypodermic electrodes were used. These were inserted sub- cutaneously into the animal's chest. A modified version of the Wheatstone Bridge was built for measuring body tem- perature. Two thermistors were connected into the circuit. One is inserted into the lizard's cloaca and measures body temperature. The other is used for measuring environmental temperature. As temperature decreased the measured body functions also declined. There was a sharp decline in all the body functions at a temperature range of 45-50 degrees F. I call this point the hibernation point. At temperatures lower than this the functions decline only slightly. GEORGIANN ESSLINGER ll Il Bowen High School Sponsor: Mr. Kenneth Lightle, Jr. My project was designed to determine the results of ultra-violet light on the healing of wounds in relationship to the effects on the skin. When xiptra-violet light was used, the wounds made a definite ad ancement in their healing rateg but with a con- tinuation of the exposures a deterioration of the skin be- came present. The first exposures brought about an erythema reaction, telangiectasia, and an advancement in healing. After ex- tended exposures of definite strength and time, the skin re- vealed small yellow patches on the treated area. The yellow patches are the last warning before the skin shows a local- ized thickening with scaling or a pearly tumor which are the basics of skin cancer being either squamous or basal. This project is still a question in the minds of doctors. The light with further study and experimentation might prove to be a great healing factor when used for a maximum time twhich at this time is unknown? without endangering the patient with the danger of epithelioma. Histologic Technic in Diagnosing Leukemia NORMAN LOUIS Fosren lei Jacksonville High School Jaclcsonville, Illinois After discovering by experimentation last year that at least 7506 leukemic prone mice developed the disease by the age of eleven months, the writer wished to discover whether there were basic changes in the tissue caused by the malady. Histology, the method of taking living tissue and pro- cessing it so that the tissue may be microscopically ex- amined, was the next logical step. The complete procedure of histologic technic was learned and, after much practice, perfected. Nine stains were em- ployed in an attempt to find one that would be of assistance in the diagnosis of leukemia. Tissue from the 55 AKRXJ mice disected during the previous experimentation was taken from the solution of 1092 buffered neutral formalin, cut dehydrated, cleared, in- filtrated with paraffin, embedded, cut at about six microns with a microtome, mounted, stained, and coverslipped. Staining was done in three different ways: the staining raclil rgethod, the coplin jar dip method, and the routine met o .