Week 1: Introduction, genes and behavior Flashcards
Big questions of Behavioral Neuroscience
How important are genes for behavior?
How is the nervous system affected by emotions?
Central Nervous System
The brain and spinal cord; anything along the midline of the body and encased in bone
Peripheral Nervous System
Everything outside of the central nervous system. Sensory and motor nerves to external and internal organs
Neurons
Fundamental, interconnected cells that dictate behavior with their activity. Communicate precisely and quickly; 90 billion cells with multiple connections each
Glia
Support cells that facilitate neuron activity and allow for connection to other parts of the nervous system
Early History of Neuroscience
Brain was ignored in ancient science; only some focus on head trauma changing behavior. Early brain drawings appear during the Renaissance; advancements at this time usually followed machine development.
Neuroscience Developments of the 1800s
Localization of function became popular; opposed previous holistic views. Emphasis on phrenology and materialism. Extreme views, but have some modern day support
Phrenology
Measuring skull shape to predict behaviors and traits in a human. Defunct science
Materialism
Studying observable phenomena rather than theorizing on unobservable brain mechanisms
Post-1800s Neuroscience Development
Evolutionary theory and psychology emerged. Experimental tactics (animal studies) and lesion studies became more prevalent.
Aphasia studies
Post-1800s; found link between language impairment and brain damage. Broca’s = slow speech, Wernicke’s = meaningless
Development of Microscopy
New staining techniques allows cell research to flourish and neurons could be studied close up. Neuron studies were fathered by Ramon Y Cajal
1900s developments in Neuroscience
The interconnection of neurons (synapses and neurotransmitters) was being proposed. The Brodmann map was made in 1909. Action potentials were studied in the 40s
Broadmann map
Made to study neuron structure to map brain function and differences across the brain. Proposed that brain structure dictates function
Current/modern Neuroscience view
Groups of cells communicate to generate thoughts and behaviors and can have multiple functions
Specialization and diversity of function
Specialization
Different regions of the brain are specialized for different functions
Diversity of Function
One neuron or brain area can serve in multiple different behavior functions
Benefits of animal testing
Mice are cheap and small, easy to breed more of; more ethical, simpler to understand, and evolutionarily similar to humans; differences between human and animal nervous systems could explain behaviors
Limits of animal testing
High cost, lack of human behaviors/disorders in animals, results are not generalizable
Chronic Intermittent Stress
A simulation used to model symptoms of human depression in rodents. Usually done via the swim test or the tail hang test
Traits of a good disorder model
Parallels the real disorder in behaviors, biology (brain chemistry), and response to treatment
Shortcoming of animal testing
Most animal trials fail in humans, or are overgeneralized to humans
History of the Lobotomy
Example of overgeneralized, under-researched animal studies being applied to humans. Based on case studies and thus not representative; was given little follow up research before being widely applied. Administered due to lack of antipsychotic drugs; given to young women without gaining their consent
What to learn from the lobotomy
Use the experimental method; follow-up to verify findings; collect data and make it public; stay humble, stay critical, stay cautious
Epigenetics
Environmental affects on gene expression throughout life (same gene, different expressions based on environment)
Reasons behind genetic research
Tracking if disorders are gene-related and if genetic similarity predicts trait similarity. Most often done with twin studies
DNA
Composed of nucleotides. Differences in DNA stem from differences in base pair sequences. Order of the bases determines what kind and how much of a protein the DNA makes
Regulatory sequences
Parts of DNA that switch gene expression on and off
Coding sequences
Parts of DNA that determine what protein is made by the strand
Genes and behavior
Genes are correlated with behavior, but both genetics and environment matter when determining behavior. Genetic proteins are vital to enzymes, receptors, and neurotransmitters that drive behavior)
Polygenic vs. Monogenic
Polygenic means the trait is determined by multiple genes. If a trait is determined by one gene (monogenic), it is a disorder
Heritability
Estimated proportion of variability explained by genetics (average 0.44-0.55). How much genes matter for expressing a trait compared to environment
Low heritability = more likely to affect anyone given specific environmental situations (like anxiety)
Single gene specified disorders
If disorders are linked to one specific gene that can be tested for, there can be preventative measures put in place (PKU example).
