Neuroscience Basics Flashcards
What are the organizing principles of the brain?
thats what the lecture will try to respond
What is Neuroscience?
Researchers in the field of neuroscience—the study of the brain and the rest of the nervous system—overwhelmingly believe that the brain is the seat of learning and
memory.
Historically, most early studies of learning and memory focused on observable behavior rather than on the brain and how it functions.
————
Localization of function versus equipotentiality: where do we stand?
- in the middle we belive there is some localization but it is also works at a network(regions of the brain work together)
What is Neuroscience?
cognitive neuroscience:
* focusing on research in humans
* we can understand humans mind better by using langugue
behavioural neuroscience
* focuses on research in non-human animals.
* we are strictly using bhevaiour -brain activity (can not ask them what they are thinkig!)
The Human Brain: Orientation
- Superior: top of the brain
- Anterior front of the brain
- Posteriorback of the brain
- Inferirorbottom of the brain
another name for brain orientation (need to know as well)
- Dorsal: top of the brain
- Rostral front of the brain
- Caudalback of the brain
- Ventralbottom of the brain
Cortex:
brain tissue covering the top and sides of the brain, involved in many functions
Brainstem:
- **connects the rest of the brain to the spinal cord **
- plays critical roles in regulating automatic functions (e.g., breathing and body temperature)
Cerebellum
- back of the brain
-
regulation and coordination of complex voluntary muscular
movement
Two Hemispheres
left and right
slices of the brain
- chrono slice : slicing the brain in the middle ( left to right) hipocampus
- horizontal slice: slicing and dividing top and bottom of the brain
- Sagittal slice: pictures of the brain uses this slice in anatomy text books
- why ? brain scans and for reserch
- can do when someone is alive or dead
The Human Brain: Lobes
Frontal lobe: (front)
* plan
* perform actions
* among other things
Temporal lobe: (side)
* language
* auditory processing
* learning
* memory,
* among other things
Parietal lobe: (top left)
* processing somatosensory (touch) inputs
* among other things
Occipital lobe: (back)
* important for visual processin
Comparative Neuroanatomy
- Humans have a disproportionately
large cerebral cortex.
(Larger cortical proportion in other
animals considered clever, such as
dolphins and chimps) - Brains vary both in overall size, and in relative proportions.
- this May related to specialization. Birds have bigger proportioned cerebellums than humans. This may relate to the motor coordination necessary for fligh
- Bigger isn’t necessarily better. Elephant brain is bigger (~5 kg) then Human brain (~1.4 k)
Incoming Stimuli: Sensory Pathways into the Brain
Regions of the cerebral cortex are
specialized for processing difference sensory info:
* light (primary visual cortex),
* sound (primary auditory cortex)
* sensation (primary somatosensory cortex).
* Other regions are specialized for generating movements (primary motor cortex)
where these primary cortext are
- primary mototr cortext - top of the brain
- primsry somatosensory cortext( top of the brain
- primary auditory cortext(side of the brain)\
- primary visual cortext- back of the brain
Grey Matter versus White Matter
- white matter - axons
- grey matter- cell body
White Matter Paths
we can image them in different ways(colorful ways)
Some Brain Regions Involved in Memory
Many of these are “subcortical”
* basal ganglia - middle
* thalamus - -next to/ na ponta do basal ganglia/em baixo do basal
* amygdala - bolinha no final do hipocampus
* Hipocampus - continuacao do basal que conecta com a amygdala/parte de baixo do basal
try to fo the diagrem in the slide
central nervous system”
- Brain and spinal cord
- The “central nervous system” connects to the body (organs,
muscles) (peripheral nervous system)
The Human Brain - What is it made of?
- Close to 100 billion neurons
- Other types of cells (numerous)
- Blood vessels
there is many ways a neuron can look like
(1) Neurons
The prototypical neuron has three main parts:
-
Dendrites are input areas that
receive signals from other neurons - The cell body integrates signals from the dendrites
- One or more axons, which
transmit signals to other neurons
Other cells: Glia
Glia: cells of various types. They provide functional or structural support to neurons. Some contribute to changes in connections between neurons
○ Astrocytes
○ Oligodendrocytes
○ Does glia have other functions? More evidence is needed.
Astrocytes
line the outer surface of blood vessels (in the brain)
Oligodendrocytes
○ Oligodendrocytes wrap the axons in myelin, a fatty substance that insulates electrical signals transmitted by neurons that makes the transmission faster
Blood vessels
blood vessels very important to provide air and nutrients to the brain
How do Neurons Communicate?
The Synapse!
the Synapse
● Synapse –specialized for chemical communication between axon and dendrite, where the two cells draw very close but do not quite touch
● Presynaptic side – The axon has vesicles loaded with neurotransmitters.
● Postsynaptic side – The dendrite is lined with receptors to detect the neurotransmitter
neurotransmitters
● chemical substances that can cross a synapse to affect the activity of a nearby (postsynaptic) neuron
● Several different chemicals act as neurotransmitters
○ Glutamate, gamma-aminobutyric acid (GABA), acetylcholine, dopamine,
norepinephrine, epinephrine, and serotonin
Receptor
● are molecules embedded in the surface of the postsynaptic neuron.
- They are specialized to bind with and respond to certain neurotransmitters (like a lock and key)
Excitatory
● Some neurotransmitters—glutamate, for example—are excitatory.
- They activate receptors that tend to increase the likelihood of the postsynaptic neuron firing
Inhibitory
- Other neurotransmitters— such as GABA—are inhibitory.
- They activate receptors that
tend to decrease the likelihood of the postsynaptic neuron firing.
Neuromodulator:
a subtype of neutrosmetters
- a neurotransmitter that modulates activity in a large number of neurons rather than at a single synapse.
○ Example: Dopamine
The Plot Thickens
● When an action potential occurs, there is a lot of stuff happening
○ Calcium enters the cell and that triggers neurotransmission
○ Neurotransmission, in turn, can spur an action potential
● Neuronal communication is electrical AND chemical!
How does this all relate to learning and memory?
● Learning and memory researchers have focused almost exclusively on understanding the the ability of synapses to change as a result of experience (synaptic plasticity)
● “Hebbian learning”: any physical change in neurons can affect neural communication, that is, the connections between neurons
○ Learning that involves strengthening connections between neurons that work together
● These ideas were more hypothetical at the time of Donald Hebb (strong evidence came later)
● “Neurons that fire together wire together” - neuron firing changes as consequence of experience
Long-term potentiation (LTP):
- a process in which synaptic transmission (between neurons) becomes more effective as a result of recent, repeated activity - think as a habit
● LTP is believed to represent a type of synaptic plasticity, which could be a neural mechanism for learning
Long-Term Potentiation: Original Studies
(A) Researchers used an electrode to stimulate the axons of presynaptic
neurons. A second electrode was used to record the activity of postsynaptic neurons.
(B) Initially, weak stimulation caused only a mild response in the postsynaptic neuron.
But after a burst of high-frequency stimulation, the postsynaptic neuron responded more strongly to the weaker stimulation and this persisted
