PSYA01H3 Chapter Notes -Sympathetic Nervous System, Carl Wernicke, Electric Shock

35 views6 pages
3 Feb 2013
Neuroscience and behaviour (chapter 3)
Neurons: the origin of behaviour
- Neurons: cells in the nervous system that communicate with one another to perform
information processing tasks
The discovery of how neurons work
- Santiago ramon y cajal, new technique for staining neurons in the brain
- Information processing units of the brain and that even though he saw gaps between neurons
they had to communicate in some way
Components of the neuron
- Cell body: the part of the neuron that coordinates information processing tasks and keeps the
cell alive (soma) protein synthesis, energy production, metabolism take place here
- Nucleus, houses chromosomes that contain your dna or the genetic blueprint of who you are
- Dendrites: receives information from other neurons and relays it to the cell body
- Axon: transmits information to other neurons, muscles, or glands
- Myelin sheath: an insulating layer of fatty material
- Glial cells: support cells found in the nervous system, digest parts of dead neurons, provide
physical and nutritional support for neurons
- Myelin performs this same function for an axon
- Dennyelinating diseases
- Synapse: the junction or region between the axon of one neuron and the dendrites or cell body
of another
Major types of neurons
- Sensory neurons: neurons that receive information from the external world and convey this
information to the brain via the spinal cord
- Motor neurons: carry signals from the spinal cord to the muscles to produce movement, have
long axons that can stretch to muscles at our extremities
- Interneurons: connect sensory neurons, motor neurons, other interneurons, carry information
from sensory neurons into the nervous system to motor neurons, and still others perform a
variety of information processing functions within the nervous system
Neurons specialized by location
- Purkinje cells are a type of interneuron that carries information from the cerebellum to the rest
of the brain and spinal cord
- Pyramidal cells, found in the cerebral cortex have a triangular cell body and a single long
dendrite among many smaller dendrites
- Bipolar cells
The electrochemical actions of neurons: information processing
- Conduction and transmission
- Resting potential: the difference in electrical charge between the inside and outside of a
neuron’s cell membrane
- Arise from the difference in concentrations of ions inside and outside the neuron’s cell
- Negative
Unlock document

This preview shows pages 1-2 of the document.
Unlock all 6 pages and 3 million more documents.

Already have an account? Log in
The action potential: sending signals across the neuron
- Action potential: an electric signal that is conducted along the length of a neuron’s axon to the
- Electric shock reaches a certain level. Threshold
- Shock below threshold tiny signals
- All or none
- There is change in the state of the axon’s membrane channels
- Refractory period: the time following an action potential during which a new action potential
cannot be initiated
- Myelin sheath
- Nodes of ranvier
Chemical signaling: transmission between neurons
- Terminal buttons: knoblike structures that branch out from an axon
- Neurotransmitters: chemicals that transmit information across the synapse to a receiving
neuron’s dendrites
- Receptors: parts of the cell membrane that receive the neurotransmitter and initiate or prevent
a new electric signal
- Presynaptic neuron
- Postsynatptic neuron
- Synaptic neuron
- Reuptake occurs when neurotransmitters are reabsorbed by the terminal buttons of the
presynaptic neuron’s axon
- Enzyme deactivation
- Neurotransmitters can bind to the receptor sites called autoreceptors on the presynaptic
- Autoreceptors detect how much of a neurotransmitter has been released into a synapse and
signal the neuron to stop releasing the neurotransmitter when an excess is present
Types and functions of neurotransmitters
- Acetylcholine (ach): a neurotransmitter involved in a number of functions, including voluntary
motor control
- Dopamine: a neurotransmitter that regulates motor behaviour, motivation, pleasure, and
emotional arousal
- Glutamate: a major excitatory neurotransmitter involved in information transmission
throughout the brain
- Gaba(gamma aminobutyric acid): the primary inhibitory neurotransmitter in the brain
- Norepinephrine: a neurotransmitter that influences mood and arousal
- Serotonin: a neurotransmitter that is involved in the regulation of sleep and wakefulness, eating
, and aggressive behaviour
- Endorphins: chemicals that act within the pain pathways and emotion centers of the brain
How drugs mimic neurotransmitters
- Agonists: drugs that increase the action of a neurotransmitter
- Antagonists: drugs that block the function of a neurotransmitter
- Methamphetamine affects pathways for dopamine, serotonin, and norepinephrine at the
neuron’s synapses, making it difficult to interpret exactly how it works
Unlock document

This preview shows pages 1-2 of the document.
Unlock all 6 pages and 3 million more documents.

Already have an account? Log in

Get OneClass Notes+

Unlimited access to class notes and textbook notes.

YearlyBest Value
75% OFF
$8 USD/m
$30 USD/m
You will be charged $96 USD upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.