Neuroscience Quiz Flashcards
Grey matter corresponds to…
Cell Bodies
White matter correspond to…
Axons
Subcortical Structures
Ventricles
Thalamus
Putamen
Caudate Nucleus
Brainstem
Pons
Hippocampus
Amygdala
Network of blood vessels that line the ventricles and produces CSF
Choroid Plexus
T or F: Injection into the ventricles allow spread and diffusion throughout the brain (intracerebroventricular injection)
True
Frontal Lobe
attention, executive functions (planning, decision making), impulse control, personality
True or False: Humans have a small frontal lobe relative to other mammalian species
False: Humans have a large frontal lobe
________ particularly challenging for prefrontal cortex
Translation
Parietal Lobe
processing somatosensory, includes touch, pain, temperature, and the sense of limb position
integrates information from different modalities
Occipital Lobe
vision, depth perception, colour recognition
Temporal Lobe
episodic memories, integrating memories with sensations of taste, sound, sight, and touch
hearing
True or False: All of these lobes work together for memory
True
Lateral (Sylvian) Fissure
the most prominent sulcus of each cerebral hemisphere in the human brain. The lateral sulcus is a deep fissure in each hemisphere that separates the frontal and parietal lobes from the temporal
Central Sulcus
a prominent groove on the lateral surface of the cerebral hemisphere that separates the frontal and parietal lobes. It plays a crucial role in defining the primary motor cortex anteriorly and the primary sensorimotor cortex posteriorly.
Cerebellum
coordinates voluntary movement, balance, and posture
True or False: In humans, the corpus callosum consists of about 200 million axons making it the most prominent fibre tract within the central nervous system
True
What is the importance of the corpus callosum
- connects the left and right hemisphere
- important inter hemisphere connections
Why should we care about lobe functions?
Frontotemporal dementia
- taupathy like Alzheimer’s disease
- behavioural variant
- affects behaviour, judgment, and personality
- primary progressive aphasia
Primary Progressive Aphasia
- aphasia = difficulty communicating
- affects the ability to speak
- affects the ability to use and understand language
If tau tangles and neurodegeneration are occurring in the temporal
lobe, what is likely causing the dementia?
Alzheimer’s Disease
If tau tangles and neurodegeneration are occurring in the frontal
lobe, what is likely causing the dementia?
Frontotemporal Dementia
Are brain cells, neurons, and nerve cells often referring to
the same type of cell?
yes
Does the brain have other types of cells
Yes
True or False: The brain is made up more of neurons than glial cells
False: the brain is made up of more glial cells than neurons
Glial Cell Types
Astrocyte
Oligodendrocyte
Microglial Cell
Glial Stem Cell
Oligodendrocyte Precursor —-> myelinating oligodendrocyte
What is the main function of microtubules in neurons?
Provides structural integrity for the cell and acts as a conveyor belt
Cell Organelles
Ribosomes
Mitochondria
Mictrotubules
Ribosomes
- manufacture products such as neurotransmitters, which are secreted by the cell
Mitochondria
- the power source for the cell
- they produce energy in the form of ATP, which is necessary for cell function and survival
Microtubules
- provide structural integrity for the cell
- acts as a conveyor belt system to move ribosomal products and other substances within the cell
Alzheimer’s Disease
- Tau is a microtubule-associated protein
- coded by the MAPT gene
- Tau’s primary role is to maintain the stability of microtubules in axons
- in AD, tau aggregates inside the neurons as tangles
UNDERSTANDING MICROTUBULES HELPS UNDERSTAND TAU PROTEINS
_____ carry information from PNS to CNS
Sensory neurons
_____ transmit signals from CNS to PNS
Motor Neurons
A lumbar puncture may be done to diagnose a condition
- a hollow needle is inserted into subarachnoid space in the lower back to withdraw cerebral spinal fluid
- Amyloid-beta, tau, neurofilament light, prions (e.g., Creutzfeldt–Jakob disease)
Interconnectedness of sensory and motor control and learning and memory
Tests of learning and memory in humans and animal
models rely on communicating sensory and motor
information (indirect method)
- learning and memory cannot be measured directly
When using memory tests in humans or animals, always consider the explanations for an _________
incorrect response
True or False: It’s also important to recognize the differences between
humans and our model systems
True
What is the blood-brain barrier (BBB)
- a highly selective semipermeable
border of endothelial cells that
prevents solutes in the circulating
blood from crossing into the central nervous system - protects brain from virus, virals, drugs
There are _________between neighbouring endothelial cells
tight junctions
Why is understanding the blood brain barrier important?
- drugs to treat neurological diseases, need to be able to cross the blood brain barrier or
need to be administered directly into the brain - Pathogens (virus, bacteria, fungus) have been hypothesized to contribute to certain
types of dementia - BBB is weakened in some neurodegenerative diseases
- The BBB has a circadian clock (penetrability changes with time of day)
Glympahtic Clearance
run by glial cells to help connective flow of CSF in brain
Specialized neurons important for spatial memory
- place cells
- grid cells
are active in
different locations and the
combination of activity in many
place cells creates an internal
neural map representing a
particular environment
(O’Keefe, 1976)
Place Cells
fire at regular
intervals as an animal
navigates an open area,
allowing it to understand its
position in space by storing
and integrating information
about location, distance, and
direction
Grid cells
Neurotransmitters
look at the chart
Structure of Neurons
Cell body (which contains the nucleus)
Dendrites
Axon
Axon Terminals
True or False: Neurons are connected in networks and serve many functions
True
A neuron is:
input
integrative
conductive-output
representation
Input
An input device that receives
chemical and electrical messages from other neurons
Integrative
an integrative device that combines messages received from multiple inputs
Conductive-output
a conductive output device that sends information to other neurons, muscles, and organs
Representation
a representation device that stores information about past experiences as changes in synaptic strength
What part of the neuron receives signals from other
neurons?
dendrites
What part of the neuron sends signals to other neurons?
Axons
A brain’s fire of memory
Memories from the brain’s view
are the changes in the
connectivity among a collection
of neurons responding to a
particular experience.
True or False: Changes are localized to some dedicated storage area but are distributed throughout the neural systems engaged by the memory-producing event
False:
Changes are not localized to
some dedicated storage area but
are distributed throughout the
neural systems engaged by the
memory-producing event.
Donald Hebb
proposed that modified ensembles of neurons that
he called cell assemblies could provide a substrate for
memories. His idea remains relevant today.
Cell Assembly
Sensory inputs into a distributed set
of weakly connected (dashed lines)
collection of cell assemblies…
—>
…change the strength of connections
among the neurons (solid lines) in the
assemblies.
Hebb pt 2
Donald Hebb also proposed a rule to specify how synaptic
connections can be modified:
Cells that fire together wire together
Long-Term Potentiation
- Connections between neurons are changed when the
synapse that link them are modified. - Neurobiologists want to understand how these modifications
occur. - This is a daunting task because it requires locating the
neurons that compose the assemblies that support the
memory trace (also called an engram) and their sensory
inputs. - The discovery of long-term potentiation (LTP) provided a
methodology that simplified the task.
Bliss and Lomo
- Bliss and Lømo discovered LTP by
stimulating (SE) the perforant path and recording (RE) in the dentate gyrus.
SE = stimulating electrode
RE = recording electrode
How did Bliss and Lomo discover LTP
- They first applied a weak stimulus (WS) to the perforant path and measured synaptic activity.
- They then applied a strong stimulus (SS) to the perforant path. It evoked more synaptic activity than the weak stimulus.
- In addition, the strong stimulus
produced an enduring increase in the synaptic response to the WS. This enhanced response is called long-term
potentiation (LTP).
Prior to establishing LTP, a weak test stimulus (small arrows) is repeatedly presented to establish a baseline.
- A stronger stimulus (large arrow) is then presented to induce LTP.
- The weak test stimulus is then presented to determine if the synapse was
potentiated.
LOOK AT SLIDES
The test stimulus serves two functions
- It establishes a baseline.
- It also helps determine if the inducing stimulus produced LTP–resulted in the test stimulus producing a larger response.
A synapse is composed of…
- presynaptic terminal (axon
bouton). - postsynaptic component
separated by the synaptic cleft.
When an action potential arrives in the presynaptic axon terminal:
- Neurotransmitter molecules are
released from synaptic vesicles into
the synaptic cleft. - There, they bind to specific receptors.
- This results in a chemical or electrical
signal in the postsynaptic cell.
Postsynaptic current causes….
excitatory or inhibitory
postsynaptic potential that
changes the excitability of
the postsynaptic cell.
LTP as a Model for Studying Memory Raises Two Questions
Synaptic changes that produce LTP?
* A heated debate centered on two general possibilities:
LTP is the result of:
(1) presynaptic changes that increase the release of
glutamate, or
(2) postsynaptic changes that increase the postsynaptic
neuron’s sensitivity to glutamate.
* While not denying that there can be presynaptic changes,
it is safe to assume that important postsynaptic changes
are essential to LTP (Nicoll, 2017; Vincent-Lamarre et al.,
2018).
Ionic receptors are located
in the plasma membrane
when a neurotransmitter binds to the receptor…
the channel or pore opens and allows ions such as Na and Ca to enter the cell
Three types of glutamate receptors
AMPA
NMDA
KAINATE
AMPA and NDMA receptors are located where and what is the purpose?
in dendritic spines
plays a key role in induction and expression of LTP
What happens when glutamate binds to these receptors?
their channels open and positively charged ions in the extracellular fluid (Na and Ca) enter the neuron
What can be used to enhance (agonist) or inhibit (antagonist) receptor function?
Pharmalogical Agents
True or False: (A) The NMDA receptor binds to glutamate. It also binds to Mg2+ (sometimes called the magnesium plug) because
Mg2+ binds to the NMDA
channel.
True
Opening of NMDA receptor requires two events
- ligand-gated
- volate dependent
Ligand-gated
glutamate must bind to
the receptor, and
Voltage Dependent
the cell must depolarize.
When this happens, the
magnesium plug is
removed and Ca2+ can
enter the cell.
A single cascade is initiated when a __________ an extracellular substance, such as a neurotransmitter (ex. glutamate) or a hormone binds to a cell surface receptor and initiates intracellular activity
first messenger
What is the second step in the cascade?
Second messengers
what are second messengers?
molecules that relay signals from receptors on the cell surface to
target intracellular protein kinases and phosphatases that then target other
proteins.
