Lectures 1-3

Behavioral Neuroscience

Seeks biological explanations for how we perceive, feel, think, and act; focuses on testable and mechanistic understandings without diminishing the reality of psychological experiences

Mind-brain problem

What is the relationship between the mental realm and physical body

dualism

The belief that the mind and brain are fundamentally separate (early belief system)

Monism

The belief that the brain and mind belong in the same physical reality; mental events are products of brain activity

Materialistic monolism

All thoughts, feelings, and actions arise from the physical matter; what behavioral neuroscientists believe

Relevant scientific innovation: Desortes

Created the first testable physical model of behavior, important to create an empirically verified or disprovable mechanism explanation

Relevant scientific innovation: Helmholtz

measured speed of nerve condition; important to prove that biological signaling and cognitive processing take measurable time, disproving dualism

Relevant scientific innovation: Broca

Identified that specific areas of trauma can have specific behavioral effects depending on the localized trauma spot

Gene

Provide the biochemical template for making for making proteins, not behavior

Alleles

Different versions of specific genes; most behaviors require 100s or 1000s of genes to function (polygenetic)

Non-coding genes

Junk DNA; Important to determine where and when a gene is expressed

Heritability

The proportion of total phenotypic variation in a POPULATION attributable to genetic variation

Twin studies

used to test if heritability is influenced by environment or genetic components

The vulnerability model

Genetic predispositions create risk, but environmental stressors trigger phenotypic expression

Crisper-CAS9

Tool for genetic modifications and therapeutic potential

Central nervous system

Brain + spinal cord

Nerve

Bundle of axons running together (used for the peripheral nervous system)

Tracts

bundles of axons running together (used for the CNS)

Ganglion

Groups of cell bodies in the PNS

Nucleus

group of cell bodies in the CNS

Frontal lobe

specializes in motor, speech, and executive functions

Broca’s area

specializes in Language production

Prefrontal cortex

Specializes in working memory, decision making, and impulse control

Parietal lobe

specializes in sensory processing

occipital lobe

maps visual field

Hemispatial neglect

Damage to a side of the brain that effects the other side’s spatial awareness

Temporal lobe

hearing and language recognition

Wernickes area

decodes speech meaning

Fusiform face area

Face recognition damage causes prosopagnosia

thalamus

sensory relay to cortex

hypothalamus

regulates homeostasis: coordinates ANS and ES via the pituitary gland

Dorsal

top of the brain

ventral

underside of the brain

Anterior

forehead

Posterior

back of the head

Inferior

bottom of the brain

Lateral

outer sides of the brain

medial

midline

Coronal/frontal plane

cut to have front and back side

Sagittal plane

cut to have left and right sides

Horizontal/axil plane

cut to have a top and bottom side

dendrite

branching input fibers that receive incoming chemical signals

Cell body

Contains the organelles of the neuron; integrates graded inputs

Axon hillock

Specialized junction with a high density of sodium ion channels; where the all or nothing decision is made

Axon

long slender cyclinder extender that sends out signals

Myelin sheathes

Fatty insulators wrapping by exposed nodal gaps in the neuron to produce rapid conduction

Axon terminals

Swollen tips containing synaptic vesicles that are filled with neurotransmitters

Polarization

signals traveling from dendrite to axon-to-axon terminals

Glial cells

non-neuronal cells essential for nervous system structure, singling and survival

Astrocytes

star shaped glia that provide physical support, maintain the blood brain barrier, and buffer extracellular potassium ions

Oligodendrocytes

Produce myelin sheathes in the CNS

Schwann cells

Produce myelin sheathes in the PNS; guide regeneration

Microglia

Resident immune scavengers; fight pathogens and prune inactive synapses

Radial Glia

specialized developmental scaffolding guiding embryonic neural migration

Resting membrane potential

The electrical voltage difference between the membrane when nothing is happening (-70mV)

Ion concentrations and diffusion electrostatic principles

Sodium: High concentration OUTSIDE; low inside; Both diffusion and electrostatic pressure drive ions inward

Chloride: High concentration OUTSIDE; low inside; Diffusion pushs ions out; electroc static pressures pull inward

Potassium: High concentration INSIDE; low outside; diffusion pushes ions inward; electrostatic pushes ions outward

Organic Anions

Negatively charged proteins that are trapped inside the cell to keep it negatively charged

Force of diffusion

Ions move from areas of high concentrations to low concentrations

Electrostatic pressure

the idea that postive ions are pulled to negative inside of the neuron

Sodium potassium pump

Uses atp to pump 3 sodium ions out and 2 potassium ions in to maintain gradient

Action potential

A rapid reversal of membrane polarity (from -70mV to 40mV in less than a millisecond)

Threshold of excitation

Graded depolarization triggered at the axon hilocks

Depolarization

When sodium ion channels open and sodium inons come into the cell through the electrochemical gradient

Inactivation and repolarization

Sodium ion channels are closed; Potassium ions exit the cell so that the neuron can be polar again

ALl or nothing law

an action potential occurs at full size or not at all

Rate law

stimulus intensity is encoded by the firing frequency, not height of individual spikes

Absolute refractory period

Sodium channels are inactive and no stimulus is able to trigger a spike

Relative refractory period

Sodium channels reset; spike can occur but it needs to be very strong to occur

Unmylelinated axons

Require constant conduction after action potential is acted; extremely slow conduction

Myelinated axons

Fast conduction due to insulated axon; prevents ion leakage

Nodes of Ranvier

Uninsulated gaps packed with dense clusters of sodium ion channels; action potential travels from node to node to get to axon