Cog Neuro

Neurons

Neurons

cells in the nervous system that communicate with one another to perform information-processing tasks

Glia

Cells that support the functionality of the neurons by providing physical support, supplying nutrients and enhancing neuronal communication.

Cell Body (soma)

The part of a neuron that coordinates information-processing tasks and keeps the cell alive.

Dendrites

The part of the neuron that receives information from other neurons and relays it to the cell body.

Axon

The part of a neuron that transmits information to other neurons, muscles or glands.

Myelin Sheath

An insulating layer of fatty material made up of glial cells.

Synapse

The junction or region between the axon of one neuron and the dendrites or cell body of another.

Sensory Neurons

Neurons that receive information from the external world and and convey this information to the brain vis the spinal cord.

Motor Neurons

Neurons that carry signals from the spinal cprd to the muscles to produce movement.

Interneurons

Nerons that connect sensory neurons, motor neurons or other interneurons.

Resting Potential

The difference in electric charge between the inside and outside of a neurons cell membrane.

Action Potential

An electric signal that is conducted along the length of a neuron's axon to a synapse.

Refractory Period

The time following an action potential during which a new action potential cannot be initiated.

Terminal Buttons

Knoblike structures that branch out from an axon.

Cognitive Neuroscience

the scientific study of biological substrates underlying cognition with a specific focus on the neutral substrates of mental processes. It addresses the questions of how psychological/cognitive functions are produced by neural circuits in the brain.

Why Neuroscience matters?

Humans (and animals) are biological systems

The basic assumption of all modern neuroscience and psychology: Mental functions are the product of activity in the nervous system

What does the nervous system do?

Receives sensory information from the environment Integrates and processes information Regulates internal functions Produces motor actions

Levels of Observation:

Genes & DNA - make up Cells - basic units of structure/function Tissues - groups of cells of same kind Organs - structures composed of more than one tissue, work together to perform specific function Systems - groups of organs that work together to perform specific function Body

Structure of a living cell:

Nucleolus Nucleus Mitochondria Channels Other proteins Membrane

How many cells are there in the brain?

170 billion - 85 billion neurons, 85 billion glia cells

The structure of a neuron:

Nucleus Cell Body (Soma) Dendrites Axon Axon Hillock Myelin Sheath Axon terminal

Axon Hillock

Receives inputs from different cells and sends them along the axon.

Axon Terminal

forms synapses with dendrites of other neurons

Communication WITHIN a synapse is...

Electrical

Communication BETWEEN synapses are...

Chemical

Neurotransmitters

Chemicals that transmit information across the synapse to a receiving neuron's dendrites.

Receptors

Parts of the cell membrane that receive neurotransmitters and initiate a new electrical signal.

Spacial Summation

when the dendrites are stimulated from various neighbouring cells.

Temporal Summation

one cell repeatedly trying to stimulate a cell

Action Potential

Electricity: most single atoms have an electric charge, charged atoms are called ions An overall difference in charge between nearby areas creates an electric potential (aka voltage)

Chemistry: Diffusion - particles diffuse to equate concentrations across space

What is multiple sclerosis?

Autoimmune disease where one's own immune system damages the myelin sheath.

Type of neuron in the cerebellum?

Purkinje cell

Type of neuron in hippocampus?

Pyramidal cell

Type of neuron in Retina?

Bipolar cell

Motor neuron disease is...

a family of diseases in which motor neurons degenerate and die, leading to weakness, paralysis and eventually death

Synaptic Transmission

Communication BETWEEN neurons

EPSP

Excitatory Post-Synaptic Potential

IPSP

Inhibitory Post-Synaptic Potential

Excitatory Signal

tells neurotransmitter to fire

Inhibitory Signal

tells neurotransmitter NOT to fire

Glutamate

most common excitatory neurotransmitterimportant for learning and memory too much -> seizures/migraines OCD

GABA (Gamma-aminobutyric acid)

most common inhibitory neurotransmitter counteracts glutamate regulates and prevents over-excitation GABA deficiency -> seizures, tremors, insomnia/increased responsiveness to stress Increased risk of anxiety disorders and phobias

Acetylcholine (ACh)

Regulates motor control Excitatory in synapses between neurons and skeletal muscles Inhibitory in synapses between neurons an the heart important for attention, learning, memory, arousal... too much -> role in depression deficiency -> alzheimer's disease -> degeneration of cholinergic neurons

Dopamine

Important role in movement, motivation Tied to addiction too much -> inked to schizophrenia deficiency -> tremors, difficulty initiating and stopping movement -> parkinsons disease

Serotonin

regulates mood, appetite, sleep involved in arousal and aggression involved in cognitive functions -> learning and memory

Endorphins

chemicals that act within the pain pathways and emotion centres of the brain

Agonists

drug that mimics or increases the action of a neurotransmitter

Antagonist

Drug that blocks the effect of a neurotransmitter

Block reuptake agonists:

Prozac (selective serotonin reuptake inhibitor) & Cocaine (blocks dopamine, norepinephrine & serotonin reuptake)

Increase production of neurotransmitter agonist:

L-dopa (precursor of dopamine, used for parkinson's)

Increase neurotransmitter release agonist:

Amphetamines (stimulate release of dopamine and norepinephrine)

Agonist - Blind and activate post-synaptic receptors:

Nicotine (activates Ach receptors) Cannabis (activates CB1 cannabinoid receptor - anandamide)

Antagonist - prevent release of neurotransmitter:

Botulinum Toxin (prevents ACh vesicles from fusing with membrane)

Antagonist - bind to post synaptic receptor and block it:

Haloperidol (prevents dopamine from activating receptors by blocking them; used to treat schizophrenia)

Nervous System

an interacting network of neurons that conveys electrochemical cells throughout the body -> the bodys command centre

Central Nervous System (CNS)

part of the nervous system that is composed of the brain and the spinal cord

Peripheral Nervous System (PNS)

part of nervous system that connects the central nervous system to the body's organs and muscles "outside the brain and spinal cord"

Somatic Nervous System (SNS)

nerves that convey information into and out of the central nervous system important for forming movements attached to bones/tendons that allow us to move

Automatic Nervous System (ANS)

set of nerves that carry involuntarily and automatic commands that control blood vessels, body organs and glands.

Sympathetic nervous system

A set of nerves that prepare the body for action in a threatening situation. increases arousal survival related action FOUR F'S

Parasympathetic Nervous system

a set of nerves that help the body return to a normal resting state reduces arousal

Sympathetic and parasympathetic nervous systems act in a _________ manner...

CO-ORDINATED

SYMP vs PARASYMP

• eyes

• bronchi

• heartbeat

• digestive activity

• glucose release/gallbladder

• adrenaline??

• bladder

• sex organs?

Central Nervous System Terminology: 4 Legged Mammal

• Front

• Back

• Above

• Below

Front - rostral/anterior Back - caudal/posterior Above - dorsal Below - Ventral

Central Nervous System Terminology: 2 Legged Mammal (Human)

• Front

• Back

• Front

• Back

Front - rostral/anterior Back - caudal/posterior Front - Ventral Back - Dorsal

Central Nervous System Terminology: In the Brain

• Above

• Below

Above - Dorsal Below - Ventral

Spinal Column

• made up of tiny bones

• vertebrae protect the spinal cord

Spinal Reflexes

Simple pathways in the nervous system that rapidly generate muscle contractions

Hindbrain

An area of the brain that coordinates information coming into and out of the spinal cord.

Dorsal horn location and function...

back of spinal cord receives sensory information

Ventral horn location and function...

Front of spinal cord sends signals to thee body to initiate motor movement

Gray matter (cortex)...

where the cell bodies are in the brain (dendrites)

White matter...

where myelinated axons are in the brain

Left/Right function in the brain...

Left control right side of body Right controls left side of body

Left/Right function in the spinal cord...

Left controls left side of body Right controls right side of body

Dorsal/Ventral Horn effect whether one has difficulty with....

Paralysis (ventral) Sensation (dorsal)

Folds within the brain allow for more...

cortex

Name the view/slice of the brain...

Horizontal/Axial/Transverse

Name the view/slice of the brain...

Sagittal

Name the view/slice of the brain...

Coronal

The 3 major divisions of the brain are....

Forebrain Midbrain Hindbrain

Hindbrain

an area of the brain that coordinates information coming into and out of the spinal cord

The hindbrain is phylogenetically ancient means that....

it was the first developed part of the brain (in terms of evolution)

The 4 parts to the hindbrain are...

Pons Medulla Reticular Formation Cerbellum

Medulla

an extension of the spinal cord into the skull that coordinates heart rate, circulation and respiration vital to survive -> damage can cause heart and lungs to stop

The term "brain stem dead" means....

There has been damage to the medulla

Reticular Formation

regulates sleep/wake cycle & arousal levels

cerebellum

controls fine motor skills

Pons

relays information from the cerebellum to the rest of the brain

Midbrain

Important to coordinate the basic functions related to perception and action

Tectum

spatial orienting to an environment

In the tectum, the SUPERIOR colliculi is responsible for...

visual orientation

In the tectum, the INFERIOR colliculi is responsible for...

auditory orientation

Tegmentum

movement, arousal and pleasure seeking

Substantia Nigra

part of tegmentum high level of dopamine can give it a dark colour plae colour -> parkinsons

Forebrain

highest level of the brain - both literally and figuratively split into the cerebral cortex and the subcortial structures

Cerebral cortex

outermost layer of the brain - visible to the naked eye and split into two hemispheres

Subcortial structures

areas of the forebrain housed under the cerebral cortex near the very centre of the brain

Basal Ganglia

plans initiation of intentional movements

Thalamus

relays and filters information from the senses to the cortex (except smell)