NEURO Exam 1 Review

Afferent

Information arriving from the PNS to the CNS

Efferent

Information exiting the CNS to the PNS

Dorsal (superior)

structure on top

Ventral (inferior)

structure below

Rostral (anterior)

towards the front of the brain

Caudal (posterior)

towards the back of the brain

Coronal slice

cut vertically from anterior to posterior

Horizontal slice

cut dorsal-ventral; separating the top of the brain from the bottom

Sagittal slice

cut parallel to midline, separating left and right side of the brain

Frontal lobe function

controls voluntary movement (motor cortex)

Parietal lobe function

processes body sensations (perception of touch and pain); primary somatosensory cortex

Temporal lobe function

sensory processing (sound, comprehension, language, memory); primary auditory cortex

Occipital lobe function

vision

Where is the primary motor cortex located?

precentral gyrus

Where is the primary somatosensory cortex located?

postcentral gyrus

What is neuroscience?

the study of the nervous system

What are the most common species used in neuroscience research?

Mice and rats

How is neuroscience an “integrative” field?

It is a combination of multiple fields in order to give the opportunity to answer questions about the brain from different angles

How does the biology field intersect with neuroscience?

To understand underlying process of a living organism/brain/cell

How does psychology field intersect with neuroscience?

To understand behavior and brain from a “top-down” view (whole being); neuroscience focuses on a “bottom-up” view (smaller components to explain behavior).

How does chemistry field intersect with neuroscience?

Chemicals are endogenous (originates within our body) and controls signals & communication; other chemicals are exogenous (from outside the body) and influences cell function

Ex: neurotransmitters, hormones

How does physics field intersect with neuroscience?

electrical signaling; cells carry a specific charge/voltage

Ex: action potential

What is action potential?

rapid and extreme changes to a cell’s voltage allowing the cell to send signals to other cells

Central nervous system (CNS)

the brain and spinal cord

Peripheral nervous system (PNS)

other nerve cells in the body

What are the major divisions of the brain?

Forebrain (prosencephalon)

Midbrain (mesencephalon)

Hindbrain (rhombencephalon)

What are the subdivisions of the brain?

Prosencephalon: telencephalon + diencephalon

Mesencephalon

Rhombencephalon: metencephalon + myelencephalon

What structures are found in the subdivisions of the brain?

Telencephalon: cerebral cortex, basal ganglia, limbic system

Diencephalon: thalamus, hypothalamus

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Mesencephalon: tectum, tegmentum

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Metencephalon: cerebellum, pons

Myelencephalon: medulla oblongata

What structure separates the frontal & parietal lobes?

Central sulcus

What structure separates the temporal lobe?

Lateral (sylvian) fissure

What structure separates the hemispheres?

Longitudinal fissure

What connects the hemispheres?

The corpus callosum (large, thick band of nerve fibers)

What landmarks can you identify in a dorsal view of the brain?

Lobes: frontal, parietal, occipital, longitudinal fissure, central sulcus, precentral gyrus, postcentral gyrus

What landmarks can you identify in a ventral view of the brain?

Lobes: frontal, temporal, olfactory bulbs, cranial nerves, optic chiasm, mammillary bodies, pons, medulla, cerebellum

What landmarks can you identify in a midsagittal view of the brain?

All four lobes, corpus callosum, cingulate gyrus, thalamus, hypothalamus, ventricles, midbrain (tegmentum and tectum), pons, medulla, spinal cord, cerebellum, brainstem

What structures can be found in the limbic system?

thalamus, hypothalamus, amygdala, hippocampus, cingulate gyrus, basal ganglia

What structures can be found in the basal ganglia?

globus pallidus and striatum (caudate, putamen)

What is the function of the thalamus?

“relay station”, every sensory modality (sight, taste, touch, hearing)

What is the function of the hypothalamus?

coordinates endocrine system (homeostasis: body temp, hunger, mood

What is the function of the amygdala?

regulates emotional and fear response

What is the function of the hippocampus?

memory and spatial awareness; memory factory

What is the function of the cingulate gyrus?

processes emotion, regulates behavior, pain response

What is the function of the basal ganglia?

coordinate movement

What is the function of the brainstem?

regulates vital functions (heart rate, breathing, sleep)

What are the major components of a typical cell?

plasma membrane, cytoplasm, nucleus, mitochondria, ribosomes, ER (smooth & rough), golgi apparatus, lysosomes

What are the key properties of a plasma membrane?

• phospholipid bilayer and embedded proteins

• selectively permeable

  • controls passage of ion channels and organic molecules

What is ATP and why is it important?

It generates energy for cell; primary energy source

What is the process through which DNA results in proteins?

DNA → mRNA → Proteins

What is the “central dogma of biology”?

One-way flow of genetic information to protein

Transcription: DNA → mRNA

Translation: mRNA → Protein

What is a cation?

Net positive charge due to missing electrons (Na+, K+, Ca++)

What is an anion?

negative charge due to gaining electrons (Cl-)

What do monovalent ions have?

Net charge with a magnitude of 1 (Na+, Cl-)

What do divalent ions have?

Net charge with a magnitude of 2 (Ca++)

What is the brain made out of?

Billions of specialized nerve cells (neurons) and glia

• communicates using electrical and chemical signals

• 80-90 billion of each

How have we come to learn about the brain?

Anatomical studies, brain-mapping, modern technology, histological methods (staining and immunihistochemistry)

What makes a neuron different from other cell types?

• Specialized for rapid communication

• Electroactive; charged cells that can change their charge

• “Forever” cells; after adulthood: no division, permanent loss, lifelong

• Capable of changing their structure and function

• Excitable (generate action potentials)

What are the parts of a typical neuron?

Dendrites, cell body (soma), axon, axon hillock, axon terminal (presynaptic terminal)

What are the names of the processes that extend from the cell body of a neuron?

Dendrites and axons

What are the main roles of the parts of a neuron?

Dendrites: receive signals

Cell body (Soma): integrate signals

Axon: send signals

Axon terminal: release neurotransmitters

What are the glia cells in the CNS

Astrocytes, oligodendrocytes, microglia

What are the glia cells in the PNS?

Schwann cells

What are astrocytes and their functions?

• help maintain blood-brain barrier (BBB)

• provide metabolic support to neurons

  • star-shaped, most abundant glial cell

What are oligodendrocytes and their functions?

• layers of myelin around axons

• increases signal conduction speed

• A single cell can myelinate segments of multiple axons (up to 50)

What are Schwann Cells and their functions?

• provide a section of myelin sheath

• assist in damaged nerve regeneration

• A single cell myelinates a segment of only ONE axon

  • Only found in the PNS

What are microglia and their functions?

• act as immune cells

• identify & destroy dying cells, foreign pathogens, protein clumps

• Active in immune defense and synaptic pruning

• Smallest glia and make up 10-15% of brain cells

What are Ependymal Cells and their functions?

• lining of glia inside the ventricles

• produce CSF

• columnar with small fingerlike extension (cilia) that extend into ventricles

Why is it difficult to study brain tissue?

• Soft, fatty tissues

• Cells are tiny

What is a Golgi stain?

it stains the entire neuron; highlights different shapes

What is a Nissl stain?

it stains cell bodies (nucleus of cells and the rough ER)

What is an experimental design?

Goal to establish a casual relationship between one changing factor and an influenced factor

What is the independent variable?

manipulated/changing factor

What is the dependent variable?

measured outcome/influence of independent variable

What is the main goal of scientific research?

Identify casual relationships

What are the experimental preparations?

in vivo, ex vivo, in vitro

What is in vivo?

intact, living organism (human or nonhuman)

What is ex vivo?

extracted tissue (section of living organism; Ex: brain slice or biopsy)

What is in vitro?

in dish/glass; isolated molecules

What is contralateral?

opposite sides

What is ipsilateral?

same side

What is the dura mater?

thicker outer layer surrounding brain

What is the arachnoid membrane?

web-like membrane between the dura and pia mater

What is the pia mater?

thin layer on brain surface; clings closely to brain

What are the pros and cons of computerized tomography (CT)?

produces image of brain

• Pros: fast and inexpensive (can quickly identify tumors and bleeding)

• Cons: poor resolution

What are the pros and cons of magnetic resonance imaging (MRI)?

manipulates hydrogen atoms that can then be detected in different concentrations in different tissues

• Pros: improved resolution compared to CT scans

  • Cons: expensive, slower

What are the pros and cons of microelectrodes?

record activity of single neurons (single-unit recordings)

• Pros: can be used for acute or chronic recordings

• Cons: invasive, requires specialized recording equipment ($$$)

What are the pros and cons of electroencephalograms (EEGs)?

records brain activity by placing macroelectrodes on scalp

• Pros: typically non-invasive, can detect alterations like seizures or activity of specific brain regions during certain behaviors

• Cons: cannot detect the activity of individual neurons

What are the pros and cons of functional MRIs (fMRIs)?

measures brain activity by amount of oxygen in brain’s blood vessels (quantified as a blood oxygen level-dependent signal or BOLD signal)

What are the machines used for visualizing the brain ex vivo?

Cryostat or microtome

What neuroscience techniques look at the structure of the brain?

CT, MRI

What neuroscience techniques look at the function of the brain?

EEG, fMRIs, Microelectrodes (single-unit recordings)