BIOL 4220 1st EditionExam # 2 Study Guide Lectures: 13 - 27Lecture 13 (September 26)Adaptation is the change of response to the same stimulus that is repeated over time. The condition is repetition of the stimulus, and the response is a change in the response size. If the response increases, it is called sensitization. If the response is decreased, it is called habituationor desensitization. Adaptation only requires one stimulus whereas conditioning requires two stimuli to produce. It is the most basic form of learning that is universal to most animals.When a stimulus is repeated over and over again, it provides the condition in which adaptation can occurs. Without adaptation, even if the stimulus is repeated many times, the response would be exactly the same. But with adaptation, the response is usually reduced.Lecture 14 (September 29)The nervous system is a specialized organ involved in processing information from both the internal and external environments. It controls and regulates each part of the body, and provides the animal with the ability to respond to the environment appropriately for successful survival. Each part of the brain is involved in different aspects of the control and regulation. Each of these subdivisions of the brain cooperates together to form the coherent behavior and respond to the environment appropriately for survival.Lecture 15 (October 1)Synapses are the connection between neurons. Often spaces rather than physical connection. For a chemical synapse, it is the space between the axon terminal of one neuron and the dendrite (or soma) of another neuron. For electrical synapse, the connection is actually the electrical gap junction connecting the two neurons.The electrical signal (represented by action potential) is transmitted to the next neuron through the synapse. For electrical synapse, the transmission of electrical signal is conducted directly by the gap junction. For chemical synapse, the transmission of electrical signal represented by the action potential is converted into chemical signal (neurotransmitter release). The chemical signal is then converted back into electrical signal by depolarization or hyperpolarization.Lecture 16 (October 3)Neurotransmitters are biochemicals that bind with the receptors of the post-synaptic neuron. They can be classified based on the physiological or chemical characteristics. The brain can be considered as stimulated by the excitatory neurotransmitters and inhibited by the inhibitoryneurotransmitters. There is usually a balance between excitation and inhibition that provides the normal function.Neurotransmitters can be subdivided by either excitatory or inhibitory. Excitatory neurotransmitters stimulate the neuron by increasing its excitability once it is bound to the post-synaptic receptor, making the neuron more likely to fire action potentials. This usually brings themembrane potential closer to threshold by depolarizing the neuron. Inhibitory neurotransmitters inhibit the neuron by decreasing its excitability by making the neuron less likely to fire action potentials. This usually brings the neuron farther away from threshold by hyperpolarizing the neuron.Lecture 17 (October 6)The somatosensory cortex is involved in processing tactile and temperature perception of the body surface. The motor cortex is involved in producing voluntary movements by sending the motor command signals to the periphery. The visual cortex is involved in processing visual perception. The auditory cortex is involved in processing hearing perception. The association cortex is involved in integrating and associating different senses together coherently. The frontalcortex is involved in processing higher-level cognition, such as logical reasoning, abstract thinking, decision-making, and other intellectual activities.The cerebellum is involved in motor learning and complex motor coordination of the limbs. The thalamus acts as the gateway for sensory inputs before the sensory signals enters the cerebral cortex. It is involved in interpreting the emotional aspects of the sensation. The limbic system is involved in regulating emotion and memory functions. The hippocampus of the limbic system is involved in forming associative learning and associative memory. The amygdala is involved in regulating emotions, particularly conditioned fear. The basal ganglia is involved in motor initiation and motor termination.Lecture 18 (October 8)Empathy is the ability to feel other’s pain. Rats were given a maze test for memory: a t maze, cross arm, and radial arm. Since rats are nocturnal and are afraid of light, their natural instinct isto hide and use these holes to escape. The water maze involves a submerged platform into water that tests memory and anxiety. The water log test works the same way, except the rat is on a floating time. Pain thresholds lower when there is prior exposure. The are multiple methods of brain imaging. Computer Aided Tonographs (CAT or CT Scans). It is a 3D xray that measures hard tissue like aneurisms. Position Emission Tonographs (PET scans) uses a radioactive dye that will emit its position, and the concentration of chemical neurotransmitter is measured. Magnetic Resonance Imaging (MRIs) used to be called Nuclear Magnetic Resonance (NMRs), when a a really powerful magnet oscillates atoms to measure relaxation time. Functional MRIs (fMRIs) measure brain motivation as well as deoxygenated hemoglobin. Diffusive Tensor Imaging (DTI) uses MRI technology towards water diffusion anddetecting axmal pathways. Near Infrared Spectroscopy (NIRS) uses optical imaging that penetrates tissues of oxygenated hemoglobin. Lecture 19 (October 10)Magnetic encephalogram (MEG) measures electrical brain activation. Transmagnetic stimulation(TMS) stimulates the brain using magnetism, iduces neural firing, stimulates special location that can arrest brain activity. Electro encephalogram (EEG) is the sum of all electrical activities from millions of neurons in the brain because of the electricity conducting in the brain. Synchronized = high frequency and desynchronized = low frequency. Electro corticogram (EGG) involves putting electrons on top of the cortex, creating a more precise signal from the brain. Electro convulsive therapy (ECT) induces seizures using electrical stimulation, and can also be used to treat depression. Superstitious behavior is a result of operant conditioning, random association. Correlation does not equal causality.