Midterm 1 Flashcards
Nothing about behavior makes sense except in the light of ________
Nothing about behavior makes sense except in the light of brain function.
All behaviors can be explained by _____
All behaviors can be explained by physical processes in the brain.
5 Principles to understanding the biology of the mind
- Mind & brain are inseparable
- Each mental function is carries out by specific neural circuits in different regions of the brain
- All circuits are made of elemental signaling and supporting cells
- > neurons
- > glia
- Neural circuits use specific ions & molecules to generate & transmit signals
- Ions & molecules are conserved (all us same basic elements in their behaviors)
What is a behavior?
the planning and execution of a series of goal-directed movements
- Modified by internal state (emotions, memory, hormones, etc.)
- Modified by external factors (temperature, light, prey, etc.)
4 major behavioral motivations
- Fight (aggression, competition, territoriality)
- Flight (fear, escape)
- Feed
- Reproduction
Biological explanation of behavior (Tinbergen)
- Function
- how does behavior impact chances of survival and reproduction? - Causation
- what are the neural bases of the behavior? - Development
- how does the behavior change with age?
- what role do genes and experience play? - Evolution
- how does the behavior compare with similar behaviors in related species?
- how might it have arisen?
All behaviors are a result of ____________
All behaviors are a result of neural activity in the brain and spinal cord.
Mind, and even consciousness, is _________
Mind, and even consciousness, is brain activity
How mind and brain are related
Dualism
- mind & brain are separate
- based: mental experience different from physical activity in brain
Monism
- only one entity
- mind is associated with brain activity
- every mental experience and behavior is brain activity
- -> evidence
- lesions
- imaging and neural recordings
- microstimulation
- genetic manipulations
Phineas Gage
Case illustrated mental changes CAN occur with brain changes
Suggested major brain surgeries were possible
Motor and sensory homunculus
On both sides of brain
Adult plasticity
-use-it or lose-it
-weeks -> months
Microstimulation in monkeys
Sometimes brain activity can OVER-RULE actual real-world stimulation
Genetic manipulation in moles
Pair bonding can be induced with a small chemical change in the brain
What does the nervous system do?
- reception of sensory input
- integration, learning, memory, decision
- motor action
2 Types of cells
- Neurons
2. Glia
Neurons
Specialization
- shape
- -> processes have specific compartments
- excitability
- -> can produce and transmit voltage changes
Basic structure
- input
- ->dendrite
- branched structure attached to soma
- receives info from other neurons
- ->soma
- cell body of neuron
- contains nucleus
- output
- ->axon
- convey info from soma -> button
- ->terminal buttons
- budded at end of axon
- ->synapse
- junction between button and membrane of another neuron
Glial cells
“glue” that keeps neurons together
3 types
- astrocytes
- ->provide structural support to neurons (glue)
- ->clean up debris (reuptake) - oligodendrocytes
- ->support axons
- ->produce myelin sheath (one can attach to many) - microglia
- ->act as phagocytes (immune functions)
- ->protect brain from microorganisms
AP
ions
Na+ (sodium) K+ (potassium) (-, keep in; +, kick out) A- [makes inside very -- (-70) Cl- Ca++
AP
Forces
PASSIVE
- Concentration gradient
- 1st main force acting on ions - electrical gradient
- opposite charges attract
- like charges repel
AP
ion channels
SPECIFIC
VG Na+ (much easier to change)
VG K+
VG (will change shape by application of voltage)
AP steps
- resting potential
- receive stimulation
- reach threshold
- depolarization (b/c Na+ in)
- repolarization (from + to - on inside, b/c K+ leaves)
- hyperpolarization (b/c K+ channels are SLOW)
- -> Na/K pump - resting potential
Distribution across neuron membrane- K+
K+
inside 2x outside
Distribution across neuron membrane- Na+
Na+
outside 7-8X inside
Distribution across neuron membrane- Cl-
Cl-
outside 10X inside
Distribution across neuron membrane- A-
A-
ALL inside (385)
Na/K pump
During hyper polarization
- to return to rest
- runs against concentration gradient
- uses ENERGY (ATP)
- 3 Na out per 2K in
Refractory period
2 types
- absolute
- Na channel inactivation (b/c just closed)
- during repolarization - relative
- begins during hyper polarization
- lasts little longer than 1 msec
- has higher threshold
