Image Shape To Stimulate Research On The Effect And Mechanism Of The Endogenous Signal Optical Imaging In Cat Visual Cortex

Endogenous optical imaging technology, after more than decade of research and improvement, has become an extremely important technology in brain cognitive science. When animal visual cortex surface is stimulated by the visual signal, the neuronal activities result in the changes of the bioelectricity and the content of oxygenated hemoglobin and carbon dioxide as endogenous signals. These changes are followed by the corresponding variation of the optics which is captured by photosensitive charge-coupled device cameras to indicate the excited area and comparatively unexcited area in a brain region. At last the whole optical image in the brain will be showed in two-dimensional plane by the computer image processing technology.The technology is high-sensitive, without drug toxicity hurt, and can truly reflect the normal function of the cortex. So it is greatly accepted by researchers.Primary visual cortex (area 17) of cat is the first leg of receiving visual information from lateral geniculated body. Many researchers very care the problem that the reactivity of which part of area 17 and what reaction were caused by the information. Therefore, the area 17 becomes the general service part of visual cognition research. Scholars abroad and in home have done some researches of position function pillar using endogenous optical imaging technology, the results showed that the endogenous optical imaging picture formed when horizontal grating and vertical grating stimulated retinas respectively presented their mutual supplemental and confined relationship in space. However, the effects of anaesthetic influencing neuronal activities and picture form stimulation on the position function pillar activities in the area 17 have never been studied using endogenous optical imaging technology. The article researched the influences of four kinds of anaesthetic and different picture form stimulation towards endogenous optical imaging to explore the relationship between picture form stimulation and position function pillar of area 17 and their influence mechanism. The research includes three parts, the first part is the manufacture of stimulating signal, the second part is the influences of the four kinds of anaesthetic on endogenous imaging picture and the third part is the research on the influences of different picture form simulation on endogenous optical imaging picture and its mechanism.The first part is manufacture of stimulated signal. In order to satisfy the requirements of this experiment, the author made two category (three kinds) of stimulating signals on the reference of stimulated signal standard taken by predecessors by C++ language edit proceeding, vertical strip mobile grating stimulated signal (normal stimulated signal) and fish-shaped and vertical strip mingled mobile grating stimulated signal. The later kind was divided into external-concealed internal-presented stimulated signal (the key picture of stimulated signal no.1) and external-presented internal-concealed stimulated signal (the key picture of stimulated signal no.2). These stimulated signals match the requirements of the experiment after adjustment, test and verification.The second part studied the influences of the four kinds of anaesthetic (Ketamine, sulfur phenytoin sodium, pentobarbital sodium and TU desflurane anesthesia) on endogenous imaging picture in the same anaesthetics state or different anaesthetic states or different anaesthetic time by using normal stimulated signal. The result reveals that the image effect is better with ketamine anesthesia and muscle relaxants, and lesser with sulfur phenytoin sodium and pentobarbital sodium, and worst with TU desflurane anesthesia.With the same anaesthesia, the image effect is better in anaesthetic phase one and the effect is stable within beginning one hour of phase one, then the effect becomes weaker and weaker.The third part researched the influences of different picture form simulation on endogenous optical imaging picture and its mechanism. First, in the nature state, give food-training to cats for 3 weeks (give the fish to the cats that like to eat fish and give the normal food to the cats that do not like fish). The cats were given image stimulation when giving the food-training Then in the state of anesthesia, observe the influences of the stimulations of the 3 signals (made in Part I) on endogenous signal optical imaging of the primary visual cortex of cats (the ones like fish or not). The results reveal that while stimulating with normal signal and key-map singal 1, the images of cats that like fish are similar to those of the ones that don't like fish; while stimulating with key-map signal 2, the images of cats that like fish are different from those of the ones that don't like fish, and the images are also different from the images of the same ones under normal signals. This reveals that the position function column of the primary visual cortex can react to the changes of external stimulation signals. However, the reaction is not simply orientation of the costimulatory signals, but the filter of stimulating signals based on their own internal factors. The differences of reaction of different individual can't be changed by just 3 weeks' intensive study.To sum up, the optical imaging image information of endogenous signals is influenced by the types of narcotic drugs, the anesthesia state and the anesthesia time. With ketamine anesthesia and muscle relaxants, the image effect is best. In anesthesia phase one, the image signal is good within an hour. Under the same condition, the images of different individual are different. This reveals that the individual makes a reponse by filtrating the stimulating signals based on their own internal factors. The differences of reaction of different individual can't be changed by just 3 weeks' intensive training.