Chapter 1 Flashcards
What is the Mind-Body problem?
It is the question of how and why certain types of brain activity are conscious
What is the difference between monism and dualism?
Monism is the belief that mental activity and certain types of brain activity are inseperable, while dualism believes that the mind are something else from matter.
What are the three important points of Chapter 1?
- Perception occurs in the brain, therefore feeling arises from interpretation of signals from the limb - not the limb itself. Therefore, what you might see or experience is not the same as what something actually is.
- Mental activity and certain brain activities are inseparable.
- Differences in experience by individuals may be due to difference in their brain. Therefore, behavioural differences are rooted in brain differences.
What is the physiological explanation of behaviour?
It is one that relates a behaviour to the activity of the brain and other organs. The machinery of the body is what leads to certain behaviour.
What is the ontogenetic explanation of behaviour?
It is one that describes how behaviour develops. Such as seeing differences in males and females by examining behaviour at various ages and finding changes in the nervous system.
What is the evolutionary explanation of behaviour?
It is one that reconstructs the evolutionary history of a structure or behaviour - where behavioural traits are almost always modifications of something found in the ancestral species.
What is the functional explanation of behaviour?
It is one that describes why a structure or behaviour evolved as it did.
What are the ethical issues of research with laboratory animals?
Minimalists tend to accept certain types of animal research if it serves the greater good, however abolitionists believe animal killing is murder as they have the same rights as humans. It depends then what is considered ethical and non-ethical animal research.
What are neurons?
Neurons are cells which receive information and transmit it to other cells
What are the glia?
Components of the nervous system that perform many functions - such as with astrocytes, microglia, radial glia, oligodendrocytes, Schwann cells etc.
What is the difference between axons and dendrites?
While dendrites are branching structures that recieve electrical signals, axons are long single extensions that transmit the information away from the neuron.
How does the blood-brain barrier relate to protection of the brain?
Normally, when a pathogen invades a cell, the cell marks itself for the immune system to destroy it along with the pathogen. However, it can not be destroyed if it is a neuron - therefore the blood-brain barrier keeps out pathogens from damaging neurons through tightly packed cells.
How does the blood-brain barrier relate to nutrition of neurons?
The blood-brain barrier allows the transmission of certain necessary materials inside and outside the brain through mechanisms such as protein channels, ion channels and active transport. Fat soluble molecules (such as CO2, O2, Vit A and D, drugs), water, sodium, potassium, chloride, glucose, amino acids, omega 3 and vitamins tend to be exchanged.
What are the chemicals necessary for the brain’s nutrition?
Glucose (for energy), ketones, lactate, O2 and vitamin B1/thiamine (for using glucose)
Why are the bacteria in the intestines important?
They can influence behaviour, such as by stimulating the vagus nerve, releasing certain chemicals that cross the lining of the intestines into the blood etc. For a certain bacteria, affected by increased stress, can cause inflammation and mitochondrial damage.
What is the difference between action potentials and electrical transmission?
Action potentials are formed from the movement of ions and the electrical difference inside an outside the neuron, while electrical transmission is with electricity through a medium
What causes the resting potential of a neuron?
There is a difference in electrical charge between the inside and outside of a neuron. This electrical gradient is known as polarisation. The difference of the slightly negatively charged inside forms a difference in voltage which is resting potential.
How does the movement of sodium and potassium ions produce action potential?
When at rest, the inside of the axon shows a negative potential. It can then be depolarised where if it reaches above the threshold, the membrane opens the voltage-gated channels allowing sodium/potassium them to flow inside/outside the cell and producing an action potential to be carried on through the axon. At the peak of the action potential, sodium channels close.
How does the movement of sodium and potassium ions recover from an action potential?
After the voltage-gated channels for sodium shut, potassium - being in lower concentration outside the cell now - leave due to an electrical and concentration gradient to reform a resting potential. The sodium-potassium pump then restores the original distribution of ions over time.
How does an action potential propagate along the axon?
An action potential slightly depolarises the next area of the axon to start another one.
What is the all or none law of the action potential?
The law which states that the amplitude and velocity of an action potential are independent of the intensity of the stimulus that initiated it - provided the stimulus reaches the threshold. Difference in intensity are only shown via frequency or rhythm, not power.
What is the importance of the refractory period?
When the sodium channels shut, they remain so for another millisecond which is called the absolute refractory period. When the departure of potassium ions drive the membrane potential more negative for 2-4ms, there is a relative refractory period. Sodium channels need to be closed with potassium flowing out for a refractory period. It is to prevent permanent depolarisation by preventing an action potential from reinvading areas it just passed.
What is the importance of the myelin sheath?
They speed up the movement of action potentials accross the axon and conserve energy while doing so.
What is the importance of local neurons?
Local neurons have no axon and communicate only with their immediate neighbors. They dont produce action potentials - instead, graded potentials where greater amounts of stimulation produce greater depolarization. They have inhibtory effects on neighbouring cells which prevents overstimulation.
What is the gradient of metal ions that permits resting potential and how is it done?
The membrane of the neuron is selectively permeable. Sodium and potassium therefore travel through a protein pump which transports 3 sodium ions out of the cell and 2 potassium in. Sodium is pushed in due to an electrical gradient with the inside more negative than the outsde - making it attracted to the inside. The other is the concentration gradient - diffusion is then warranted.
Why do we use animals in research?
- Animals share a lot of genes and behavioral mechanisms as humans
- Animals can be bred and raised in controlled conditions
- Animals have shorter reproductive and life-cycles
Who are the founders of neurons?
Camilio Golgi and Santiago Ramon y Cajal
What are the types of neurons?
- Purkinje cells - in the cerebellum, work in timed behaviour with a lot of communication with other cells
- Sensory neurons
- Bipolar cells - in the retina, are very precise to detect small differences and therefore limited communication
- Pyramidal cells - long axons that cover long distances for farther communication
- Motor Neurons
What is an axon made of?
- Microtubules (important by forming a skeleton highway in the axon)
- Neurofilaments
- Microfilaments
Where are ion channels on a neuron?
At the nodes of Ranvier, ion channels located for action potentials as they are not covered by myelin
What are distinct examples of glia?
- Astrocytes - keep neurons in place and synchronise neural activity, it also regulates blood flow and removes waste
- Ogliodendrocytes/Schwann cells - builds myelin sheaths (Schwann is outside the brain, ogliodendrocytes are inside)
- Microglia - the brain immune cells that remove debris and old cells and triggers inflammation
What are optogenetics?
The system where involving a photoactivating gene in an organism can cause light to activate a neuron in the brain
