Lecture 8 - Research Methods

Question 1

What are the three layers of the meninges that protect the CNS?

Answer 1

The dura mater (outermost), arachnoid membrane (middle), and pia mater (innermost).

Question 2

What is the dura mater, and what is it made of?

Answer 2

The dura mater is the outermost layer of the meninges. It is made of tough, dense connective tissue that provides protection and support to the central nervous system (CNS).

Question 3

What is the arachnoid membrane, and what is it made of?

Answer 3

The arachnoid membrane is the middle layer of the meninges. It acts as a cushioning layer and contains cerebrospinal fluid (CSF) in the subarachnoid space (area between this layer and the pia mater). It is made of a web-like structure of connective tissue.

Question 4

What is the pia mater, and what is it made of?

Answer 4

The pia mater is the innermost layer of the meninges. It closely adheres to the surface of the brain and spinal cord, providing protection and nourishment. It is made of delicate connective tissue and contains blood vessels.

Question 5

How is the CNS protected differently than the PNS?

Answer 5

The CNS is surrounded by bone and meninges, while the PNS is only surrounded by regular connective tissue.

Question 6

What role does cerebrospinal fluid (CSF) play in the CNS?

Answer 6

It provides nutrients, removes waste, cushions the brain, and circulates immune system cells.

Question 7

What are the four ventricles of the brain that contain cerebrospinal fluid?

Answer 7

The two lateral ventricles, the third ventricle, and the fourth ventricle.

Lateral Ventricles: Large, C-shaped cavities in the left and right hemispheres of the brain that produce cerebrospinal fluid.

Third Ventricle: Narrow cavity located beneath the lateral ventricles that connects to them and is surrounded by various brain structures.

Fourth Ventricle: Between the brainstem and cerebellum, connecting to the third ventricle and allowing cerebrospinal fluid to flow into the surrounding areas.

Question 8

Where is cerebrospinal fluid (CSF) produced?

Answer 8

In the choroid plexus inside the brain’s ventricles.

Question 9

What are the main functions of the basal ganglia?

Answer 9

The basal ganglia are brain structures that help control voluntary movements, manage motivation, and support reinforcement learning and habit formation. They coordinate our actions, making them purposeful and effective.

Question 10

How does the basal ganglia receive input and send output?

Answer 10

It receives input from the forebrain, especially the frontal lobe, and sends output to the cerebral cortex and hindbrain.

Question 11

What is the role of the hippocampus in the limbic system?

Answer 11

It is essential for forming long-term, explicit memories like facts and events.

Question 12

What is the function of the amygdala?

Answer 12

It processes emotions, particularly fear.

Question 13

What process marks the end of neurogenesis in humans?

Answer 13

Apoptosis, or programmed cell death, which occurs around the fifth month of development.

Question 14

What is the neural tube and when does it form during brain development?

Answer 14

The neural tube is the initial structure from which the brain develops, and it forms during the first month of development.

Question 15

What is the difference between symmetrical and asymmetrical cell division during brain development?

Answer 15

Symmetrical division produces two identical neural progenitor cells, while asymmetrical division results in one cell migrating away to become a neuron or glial cell.

Question 16

What are CT scans used for in brain imaging?

Answer 16

To quickly create images of the brain and skull using X-rays, though they don’t provide high-resolution images of soft tissue.

Question 17

How does functional MRI (fMRI) differ from traditional MRI?

Answer 17

fMRI measures changes in blood oxygen levels, providing both structural and functional information about brain activity.

Question 18

What are MRI scans used for in brain imaging?

Answer 18

MRI (Magnetic Resonance Imaging) is used to obtain high-resolution images of the brain and soft tissues by using strong magnetic fields and radio waves. It primarily measures the magnetic properties of hydrogen atoms in water molecules.

Question 19

What are fMRI scans used for in brain imaging?

Answer 19

fMRI (Functional Magnetic Resonance Imaging) measures brain activity by detecting changes in blood flow and oxygenation. It relies on the magnetic properties of hemoglobin in blood, showing regions of increased activity.

Question 20

What are DTI scans used for in brain imaging?

Answer 20

DTI (Diffusion Tensor Imaging) is used to visualize white matter tracts in the brain by measuring the diffusion of water molecules along axonal pathways. It is a type of MRI that provides information about the directionality of water movement.

Question 21

What are PET scans used for in brain imaging?

Answer 21

PET (Positron Emission Tomography) scans are used to observe metabolic processes in the brain by detecting radioactive tracers (usually glucose or other molecules) that emit positrons as they decay.

PET scans are used to track specific processes, such as neurotransmitter receptor activity, though they have been largely replaced by fMRI for most purposes.

Question 22

What are EEGs used for in brain imaging?

Answer 22

EEG (Electroencephalography) measures electrical activity in the brain through electrodes placed on the scalp. It captures voltage fluctuations resulting from ionic current flows within the neurons.

Question 23

What is an excitotoxic lesion?

Answer 23

An excitotoxic lesion is a brain lesion caused by the excessive stimulation of neurons through neurotransmitters like glutamate, leading to cell death.

Question 24

What is the use of excitotoxic lesions in brain research?

Answer 24

Excitotoxic lesions are used to investigate the effects of neuronal damage on behavior and to model neurodegenerative diseases.

Question 25

What is a sham lesion?

Answer 25

A sham lesion is a control procedure that mimics the effects of a lesion without actually damaging the brain tissue, often used in experimental designs.

Question 26

What is the use of sham lesions in brain research?

Answer 26

Sham lesions are used to control for the effects of surgery or manipulation in experiments, allowing researchers to isolate the effects of actual lesions from those caused by the procedure itself.

Question 27

What is a reversible lesion?

Answer 27

A reversible lesion is a temporary lesion induced in the brain that can be reversed, typically achieved using pharmacological agents or cooling methods.

Question 28

What is the use of reversible lesions in brain research?

Answer 28

Reversible lesions are used to study the immediate effects of disrupting brain activity in specific regions without causing permanent damage, allowing for observation of behavior before and after the lesion is reversed.

Question 29

What is a radiofrequency lesion?

Answer 29

A radiofrequency lesion is a type of brain lesion created by applying high-frequency electrical currents to tissue, causing thermal damage and cell death in targeted areas.

Question 30

What is the use of radiofrequency lesions in brain research?

Answer 30

Radiofrequency lesions are used to study the effects of specific brain areas on behavior and neurological functions by selectively damaging those areas.

Question 31

What are optogenetics?

Answer 31

Optogenetics is a technique that uses light-sensitive proteins (opsins) to control neuron activity with light, enabling precise manipulation of specific brain regions for research purposes.

Question 32

How does optogenetics work?

Answer 32

By using light-sensitive proteins (opsins) to control neuron activity with light, enabling precise control over specific brain regions.

Question 33

What is stereotaxic surgery?

Answer 33

A technique that uses a stereotaxic apparatus to guide tools (like electrodes or cannulas) to specific locations in the brain.

Question 34

What is the purpose of stereotaxic surgery?

Answer 34

The purpose of stereotaxic surgery is to precisely target and manipulate specific areas of the brain using a stereotaxic apparatus, allowing for accurate placement of instruments like electrodes or cannulas for experimental or therapeutic interventions.

Question 35

How do microelectrodes measure neural activity?

Answer 35

By recording electrical signals from individual neurons or groups of neurons through tiny metal wires implanted in the brain.

Question 36

What is the role of fluorescent calcium imaging in neuroscience?

Answer 36

To monitor neural activity by tracking the fluorescence of GCaMP, a protein that glows brighter when it binds to calcium during action potentials.

Question 37

What is retrograde labeling used for?

Answer 37

To trace afferent axons and determine which brain areas send information to the region of interest.

Question 38

How do researchers create reversible lesions in the brain?

Answer 38

By injecting drugs that temporarily suppress neural activity, such as sodium channel blockers or GABA agonists.

Question 39

What is man-made fluorescent receptor technology used for?

Answer 39

To visualize neurotransmitter release in real time by designing receptors that light up when bound to neurotransmitters.

Question 40

What is the purpose of viral-mediated gene delivery in neuroscience?

Answer 40

To deliver specific DNA into neurons, enabling the expression of light-sensitive proteins or fluorescent markers for research purposes.