C. Elegans Lab Report

developed to start working like other peoples'. The rapid birth of neurons in a young brain

Caenorhabditis elegans, a type of free-living nematode that is found in soil, is the subject matter for this experiment (Marsh). C. elegans allow for an exceptional model organism because it is easily raised in the laboratory setting, it reproduces rapidly, has a short life cycle of 3 days where it develops from egg to adult worm, only 1.3mm in length, and although only having 959 somatic cells, it shares many characteristics with other multicellular organisms like having organs and a nervous system (Kaletta). These nematodes can either be a self-fertilizing hermaphrodite where each animal produces both sperm and egg, or they can be males that will mate with the hermaphrodites (Brenner). When a hermaphrodite self-fertilizes, the chance of having a male being produced is extremely low at just 0.1%, however, when a hermaphrodite is fertilized by a male, the ratio of males to hermaphrodites is generally equal making it 1:1 (Altun).

Pathogens can spread widely and affect many organisms at the same time. Several organisms evolve to become immune or to resist pathogens including humans and C. elegans. In this experiment, C. elegans avoidance assay plates were analyzed to determine if the C. elegans evolved to resist the pathogen S. marcerens.

Neurons, nerve cells, have three basic parts: the cell body, dendrites, and axon. Neurons transmit signals to other nerve cells and throughout the body. They are simple components in the nervous system. The cell body includes the nucleus, which is the control center of the neuron. The dendrite branches off the cell body and receives information. The axon is attached to the cell body and sends information away from the cell body to other cells. When the axon goes through myelination, the axon part of the neuron becomes covered and insulated with fat cells, myelin sheath. This increases the speed and efficiency of information processing in the nervous system. Synapse are gaps between neurons, this is where connections between the axons and dendrites.

Introduction: The biological membranes are composed of phospholipid bilayers, each phospholipid with hydrophilic heads and hydrophobic tails, and proteins. This arrangement of the proteins and lipids produces a selectively permeable membrane. Many kinds of molecules surround or are contained within

The cell body comprises of the nucleus and other organelles (Ward, 2010). The nucleus contains the genetic code, and this is involved with protein synthesis (He, 2013). The dendrites receive information from other neurons which are located in a close proximity (Kalat, 1995). The terminal of an axon compresses into a disc-shaped structure (Gross, 2010). This is where chemical signals also known as a neurotransmitter permit interaction amongst neurons, by means of a minute gap named a synapse (Martin, Carlson & Buskit, 2013). Both neurons which form the synapse are referred to as a presynaptic synapse (prior to the synapse) and postsynaptic (after the synapse), reflecting the direction of information flow (from axon to dendrite), (He, 2013).

The oxidation number of an atom of any free element is ZERO. Means to say there is only one kind of atom present, no charge.

Today with my group lab we had to discuss on how to design an experiment that investigated the two herbicides DCMU and DCPIP. We used Elodea leaf and Elodea is basically a genus of aquatic plants often called the waterweeds and can be found anywhere in a pond or under water. So we started by creating a solution of phenol red, by adding 5 drops of concentrated phenol red to 40mL of water, then one of our group member used a straw to gently blow air into the solution until it reaches a neutral pH. We then transferred the solution into two test tubes evenly and labeled each tube dark and light, meaning the dark one will stay in the dark and the light one will stay under light bulbs. We predicted that dark one will stay the same and the light

The act of locomotion is highly dependent on the chemosensation of the worm, Caenorhabditis elegans (C. elegans). The use of chemotaxis enables the roundworm to distinguish various volatile and water-soluble chemicals that allow for growth and survival. We investigated the complex nervous system through the use of RNA interference (RNAi). By using RNAi, we were able to nullify certain protein expressions and test specific genes to observe their involvement in chemotaxis. The experiment made use of an attractive chemical signal, diacetyl, and how the two unknown genes and two control groups would respond. C. elegans without the ODR-10 gene were not able distinguish diacetyl, whereas the absence of protein sequence K08B12.1 and gene CEH-2 were still attracted to the chemical odorant. Based on the P values of our data, we can assume K08B12.1 and CEH-2 are not involved in chemosensation or genetic redundancy may be an alternative reason.

Doctor Linqun Luo is a professor here at Stanford and currently teaches neurobiology and does research as the principal investigator in the Luo Lab as a member of the Howard Hughes Medical Institute. His primary research area is the human brain focusing on neural circuits and how they function, how precise are the connections, how they develop. To this end his lab is using fly and mouse models to study their various circuits, centering mainly on the olfactory, and exploring the early development of neural networks in mammals (Luo Lab Bio). In order to write this commentary on the topic “How do neurons connect with each other”, I have chosen two pieces to read. The first, from Science magazine, outlines the main issues, goals, and paths the world is taking to understand to understand neuroscience including the research being done to answer the question in his topic. The second paper, from Cell Press, is a much more technical paper which outlines one of the pathways Luo isolated in the olfactory cortex of mice and how their neurons may connect.

The Radical Addiction The purpose of Bruce Alexander’s experiment was to challenge the beliefs that people have about addiction. He wanted to know if addiction was still a result even when a benevolent environment was present. He wanted to look at the affects social, physical and physiological restrains have on addiction. This experiment’s purpose was to show if addiction was due to the chemical or if it was culture.

Whether aging impair learning related long-term plasticity at LESN-L7MN synapses? (Aim 1). Though several studies have brought insights into the aging associated behavioral, cellular and electrophysiological changes, none of these studies have examined learning related long-term synaptic plasticity at LE SN-L7MN synapses connections of GWR during aging. First, using the semi-intact preparation [6,34], we will measure basal electrophysiological

disease and Alzheimer’s. Severe infection that has spread to the brain, epilepsy, stroke, and the late

This article, written by CBC News in June of 2007 describes the relationship between sponges and nervous systems. The article describes that though sponges don’t possess synapses, when compared to humans, there are mass amounts of overlap. This suggests that sponges possess many of the components necessary to create synapses. Scientists also found protein structures present within sponges, which sugested tha they interact with eachother in a similar manner to how information is passed through synapses.

The purpose of this experiment is to test how location affects whether or not the clay caterpillar models will get pecked by birds. Twenty-one clay caterpillars were made and they were made to be 5 cm ± 0.01cm long and 1 cm ± 0.01cm in diameter. Seven caterpillar models were placed in each of the three locations. The three locations are my backyard, the park, and my community garden. As a control variable, all the caterpillars were placed 300 cm ± 50 cm above the ground. An equal amount of caterpillars were glued, to prevent them falling off, in similar areas such as trees, bushes, and fences. This experiment went on for three weeks. Each week is considered one trial. Each caterpillar that was pecked or not was recorded and the data was placed