master one Flashcards
DNA methylation
- Methyl group binds to a segment of DNA
- Can either decrease or increase gene expression (transcription)
What is physiological (biological) psychology?
The scientific study of the biology of behavior
Belief that the brain and the mind are the same thing
Monism
Dualism
The mind is separate from the physical brain
Monist
If you believe that there is no mind without a brain, you are a:
Confounding variable
- An outside influence that changes the effect of a dependent and independent variable
- Male sexual fatigue in Coolidge experiment
What is the Coolidge effect?
Renewed interest when introduced to a new and receptive sexual partner, even after cessation with a previous but still available partner
Genotype
A set of genes that an organism carries and is born with
Phenotype
All of an organism’s observable characteristics, which are influenced by both its genotype and by the environment
Epigenetics
Study of mechanisms of inheritance other than the genetic code
How do genes yield traits (how does genotype become phenotype)? That is, what are the biological processes that lead to synthesis of cell proteins such as receptors and ion channels?
DNA → (Transcription) → RNA →(Translation) → Protein → Trait
What gene in the amygdala contributes to neuroticism?
The gene that encodes GABA receptors
If the gene that encodes GABA receptors is highly expressed in Person A, but not Person B, who is more neurotic?
Person B
If Person B’s amygdala neurons make some GABA receptors, but Person A’s makes more which results in lower neural firing for Person A , who is more neurotic?
Person B
What type of individual would result from neurons making some GABA receptors
- Risk adverse
- FacMan
What type of individual would result from neurons making more GABA receptors which results in lower neural firing
- Bold & fearless
- Climbing wall
What are environmental influences that could contribute to someone having high or low levels of neuroticism?
Traumatic experiences, such as having a bad fall off of the climbing wall, could lower someone’s GABA receptor amount
A genetic mechanism by which two people could differ in their adult levels of anxiety/fear (neuroticism) is:
- They could have inherited genes from their biological parents that predispose them to greater/lesser anxiety/fear
- They could have had different experiences in life that caused different epigenetic changes in their amygdala gene expression
One specific molecular mechanism that could underlie high anxiety in H.B. vs. low anxiety in R.T. is:
H.B.’s gene that encodes for the GABA receptor protein in her amygdala is turned off most of the time, so her amygdala neurons fire a lot, whereas R.T.’s gene that encodes for the GABA receptor protein in her amygdala is turned on most of the time, so that her amygdala neurons fire at a low rate most of the time
Two mechanisms at the DNA level that can result in increased or decreased gene expression (i.e., that can turn genes on or off) after birth
- DNA Methylation
- Histone remodeling
DNA demethylation
- If this occurs, transcription and translation go up
- Increased gene expression
Histone remodeling
- The core around which RNA wraps changes shape –> influences the shape of adjacent DNA
- Increase or decrease in gene expression
What happened to the performance of “maze-dull” vs. “maze-bright” when they are raised by parents who perform differently on tasks?
It didn’t work
What happened when a “maze-dull” rat was placed in an enriched environment?
The rat performed as well as the “maze-bright” rat
What happened when an already “maze-bright” rat was placed in an enriched environment?
No impact
Selective breeding of “maze-bright” and “maze-dull” rats demonstrates what about nature (genes at birth) vs. nurture (genes in adulthood)?
Genetic background that predisposes to “maze-dullness” can be largely overcome by enriching experiences after birth
What is the genetic basis of PKU (phenylketonuria)?
- Genetic disorder inherited from an individual’s parents
- Due to mutations in the PAH gene, which results in low levels of the enzyme phenylalanine hydroxylase. This results in the buildup of dietary phenylalanine to potentially toxic levels
What can PKU (phenylketonuria) impact?
Intellectual problems/abnormal brain development
How can environmental (dietary) adjustment compensate for this gene abnormality?
Providing the kids with phenyl-free foods can prevent kids from suffering from the full blown disorder
How does PKU (phenylketonuria) work?
If the gene that codes for enzyme that converts phe to tyr is non-functional → body cannot synthesize DA (from tyr) → abnormal brain development
For a long time, heritability estimates for various traits such as intelligence were misleading, because they were determined from:
A relatively select (non-diverse) sample of identical twins raised apart vs. together
How can studies of monozygotic (identical) twins be used to help us better understand how environment influences traits/disease as we age?
Epigenetic differences as they age
How to test epigenetic studies of monozygotic (identical) twins
Periodic DNA sampling to screen for methylations and histone modifications
Should monozygotic twins be referred to as identical twins?
To be precise, not exactly - as they grow, each twin’s experiences change their epigenetic profiles
What are the two basic divisions of the nervous system?
- Central nervous system (CNS)
- Peripheral nervous system (PNS)
Where is the central nervous system located?
- Brain
- Spinal cord
What does the central nervous system do?
Controls most functions of the body and mind
What are the two divisions of the peripheral nervous system?
- Somatic nervous system
- Autonomic nervous system
What does the somatic aspect of the peripheral nervous system control?
- Controls voluntary muscles
- Conveys sensory information to CNS
- Interacts with the external environment
What does the afferent nerves of the somatic aspect of the peripheral nervous system do?
- Carry sensory signals from the skin, skeletal muscles, joints, eyes, ears, etc., to the CNS
- Going towards the CNS; arrive
What does the efferent nerves of the somatic aspect of the peripheral nervous system do?
- Carry motor signals from the CNS to the skeletal muscles
- Going away from the CNS; exit
What does the autonomic aspect of the peripheral nervous system control?
- Controls involuntary muscles
- Fight or flight (sympathetic)
- Rest and digest (parasympathetic)
What is an example of an autonomic aspect of the peripheral nervous system function?
Regulating the body’s internal environment
What does the efferent nerves of the autonomic aspect of the peripheral nervous system do?
- Carry motor signals from the CNS to internal organs
- Two types: Sympathetic/parasympathetic
What does the sympathetic efferent nerves of the autonomic aspect of the peripheral nervous system do?
- Fight or flight
- Energy expanding
- Fires less since you aren’t in a constant state of fear/nervousness
What does the parasympathetic efferent nerves of the autonomic aspect of the peripheral nervous system do?
- Rest and digest
- Energy conserving
- Fires more since you aren’t in a constant state of fear/nervousness
What does the afferent nerves of the autonomic aspect of the peripheral nervous system do?
Carry sensory signals from internal organs to the CNS
Which nervous system is more protected than the other?
Central nervous system
What makes the CNS better protected than the PNS?
- Mechanical protection: Skull and meninges (dura mater, arachnoid, pia mater layers), vertebrae, cerebrospinal fluid (buffer/shock absorber)
- Immunological protection: Blood-brain barrier
Which nervous system can regenerate while the other cannot?
The peripheral nervous system can
How does the PNS regenerate itself?
- Schwann cells form lines and reconnect
- Axons regrow as long as the soma is intact
What is the blood brain barrier (BBB), physically?
A highly selective permeable border made of tightly packed cells
What purpose does the blood brain barrier (BBB) serve?
Protects the brain from circulating pathogens
Dorsal (posterior)
Toward or at the back of the body
Ventral (anterior)
Toward or at the front of the body
Lateral
Away from the midline of the body
Medial
Toward or at the midline of the body
Caudal (inferior)
Away from the head or toward the lower part of a structure or the body (below)
Rostral
Towards the nose/beak
Major parts of a neuron
- Cell membrane
- Cell body
- Dendrites
- Axon hillock
- Axon
- Myelin
- Nodes of Ranvier
- Buttons
- Synapses
Cell membrane
The semipermeable membrane that encloses the neuron
Cell body
The metabolic center of the neuron; also called the soma
Dendrites
The short processes emanating from the cell body, which receive most of the synaptic contacts from other neurons
Axon hillock
The cone-shaped region at the junction between the axon and the cell body
Axon
The long, narrow process that projects from the cell body
Myelin
The fatty insulation around many axons
Nodes of Ranvier
The gaps between sections of myelin
Buttons
The button-like endings of the axon branches, which release chemicals into synapses
Synapses
The gaps between adjacent neurons across which chemical signals are transmitted
What are the major types of proteins that are embedded in a neuron’s lipid bilayer membrane?
- Ion channels
- Receptors
- Transporters
What is the role of an ion channel that is embedded in a neuron’s lipid bilayer membrane?
Regulate cation + / cation - flow in/out of cell
What is the role of a receptor that is embedded in a neuron’s lipid bilayer membrane?
- Neurotransmitters bind to them
- Signal excitation (+, increase firing)
- Signal inhibition (-, decrease firing)
What is the role of transporters that are embedded in a neuron’s lipid bilayer membrane?
- Actively move important molecules in/out of the cell
- Ex. Na+ / K+ transporter
Major cations involved with learning/memory and neurotransmitter release
- Na+
- Ca+
- K+
- Mg+
Major anion involved with learning/memory and neurotransmitter release
Cl-
What are the 3 glial cells in the CNS
- Oligodendrocytes
- Microglia
- Astrocytes
Oligodendrocytes
- Glial cell in the CNS
- Produce myelin sheath
Microglia
- Glial cell in the CNS
- Respond to injury/disease
- Clean up: Trigger inflammation, regulate synapse formation and elimination
Astrocytes
- Glial cell in the CNS
- Contribute to the blood brain barrier, regulate blood flow
What glial cell is in the PNS
Schwann cells
Schwann cells
- Glial cell in PNS
- Produces the myelin sheath and results in direct axonal regrowth after injury
What are the 3 major divisions of the brain?
- Hindbrain
- Midbrain
- Forebrain
What is located in the hindbrain?
- Medulla
- Pons
- Cerebellum
- C on picture
What is the main function of the hindbrain?
Handles the primitive parts without you realizing it
Medulla
- Part of the hindbrain
- Autonomic
- Basic life support functions (breathing, heartbeat, digestion, swallow/cough/vomit)
When people OD on opioids it makes it hard for the body to function normally and care for itself. Where do the opioids bind to the neurons?
Medulla
Pons
- Soma of “reticular activating” neurons
- Responsible for wakefulness (Raphe) /alertness (Locus Coeruleus)
Locus coeruleus
- Used in the pons
- Keeps individuals alert
- Norepinephrine releasing
Raphe
- Used in the pons
- Sleep/wake cycle
- 5-HT-releasing