Notes for Intro to Neuroscience
- Atoms are the smallest (can’t be broken down)
- Molecules are 2 or more bonded atoms
- Ions are atoms or molecules that have positive or negative charge
- Proteins are large biomolecules (thus many atoms chemically combined)
- Enzymes are proteins (thus also biomolecules, and in turn many atoms chemically
combined) that act as biological catalyst; accelerate chemical reactions.
- DNA (Deoxyribonucleic Acid) = molecule, encodes ALL genetic information, is the
blueprint for all biological life. It is stored and passed on to the next generation.
- RNA (Ribonucleic Acid) = molecule, functions as the reader of the “DNA blueprint”
- Electrical Potential: potential is created by separation from + and – due to a
membrane.
- Voltage: measure of potential energy generated by separated charges. mV used for
neurons
- Electrical Current: the flow of electricity from one point to another. Current =
voltage/resistance. They indicate the flow of positively and negatively charge ions
across the resistance of your cells’ membranes.
Lecture 1
Exam will be open book, but no time really available to look things up.
Fast questions are not multiple choice, but one-word answers; hence, STUDY WELL.
Bacteria, cell, tissue (lowest order complexity): in vitro
Invertebrates, animals, human: in vivo (alive)
Computers (for simulation): in silico
90% of animals in research are Rodents (mainly rats and mice)
Only <1% cats, monkeys, etc.
Why? Small, cheap, short breeding cycles, relatively intelligent, agile, resistant to infection,
easy to handle. Have been used for long time, much data available.
Also; mice. They have convenient genetic manipulation.
Experimental Techniques
- Manipulation
o Lesions
o Electrical stimulation
o Pharmacological
o Genetic manipulation
o Behavioral manipulation
- Monitoring
, o In vivo:
Electrophysiology (electrical)
Micro-dialysis (chemical)
Behavioral evaluation (tasks)
o Ex vivo:
Histology
Immunohistochemistry
In situ hybridization for mRNA or DNA
Stereotaxic brain surgery
- For doing precise brain surgery
- Specific equipment for the species
- Holds the head in fixed position
- Three axes move the tip
- For lesions, microelectrodes, etc.
Stereotaxic brain atlas
- Represents 3D coordinates system of a specific species brain
- Bregma, Lambda are reference points
- “2.8 mm posterior to bregma, 4.5 mm lateral, 8.5 mm ventral to find amygdala” as
an instruction for finding the spot of interest.
Micro-dialysis
- Inner and outer tube; flow of liquid
- Like a blood capillary; semi-permeable; not all molecules can pass through
- Perfusate (inflow): salt solution, similar to brain tissue. Liquid flow must be 0 net
value (important!), otherwise liquid gets pumped or sucked into/from brain.
- Dialysate is outflow; which is monitored
- Allows for:
o Monitoring of chemical events in living tissue; gives temporal information
o Continuous drug delivery
o sample tissue chemistry with high accuracy and without taking blood
Electrophysiology (different levels)
- Single ion channel
o Patch clamp recording;
Records from single channel
microscope into tissue, probe close to surface of single cell, tiny bit of
suction sucks a seal onto cell.
Reference electrode is kept in a bath.
- Single unit (one cell)
o Intracellular recording;
sharp electrode penetrates cell membrane,
extracellular reference electrode in the bath that the cell is in.
Records voltage.
Moment of penetration the -70mV is visible on the oscilloscope.
Stimulation to cell can be done: hyperpolarizing the neuron by
, applying negative current. Depolarizing by applying positive current;
done until -55mV (firing threshold), an action potential occurs.
o Extracellular recording (also for multi-unit recordings);
can be done in vivo.
Reference electrode is ground.
Record electrode very close to cell.
In multi-unit: small bundle of electrodes; data analysis techniques can
derive different contributions to different cells.
- Multiple cell recordings (see extracellular recording)
- Field potentials (parts of tissue)
o Records synchronous activity from many cells; records synaptic transmission
o Done in vivo mainly.
o Records synchronous activity from many cells; from outside (extracellular
space).
o Negativity is left behind outside from the neuron.
o In vivo: stereotaxic procedure is used for implanting electrodes
- Brain potentials; EEG, etc.
o EEG; Electroencephalogram.
Larger parts of brain recorded.
Potential differences between electrodes are measured on the scalp.
They need to have similar spatial orientation.
Mainly gives out info from dendrites of cortical neurons.
EPSP’s or IPSP’s that are aligned in same orientation.
Minor to no contribution from action potentials; too scarce and don’t
have same direction. Mostly oscillating potentials; frequency bands
with different spatial distributions.
- Genetic Manipulation (genetic engineering, etc.)
o Direct manipulation of organism’s genes. Different than inbreeding strains
(like breeding dogs). Genetic manipulation is directly on the DNA;
spontaneous mutation. Every organism’s genes can mutate, can be adaptive
or maladaptive.
Transgene: foreign DNA that is inserted into host organism.
Transgenic Organism: the organism that will/is transformed with the
transgene.
o Possibilities: 1. Foreign DNA in the form of a plasmid, only in really simple
organisms; Prokaryotes (bacteria, viruses). 2. Foreign DNA integrated into
host genome (in mammals).
o Use:
modification of crops,
produce biomedical molecules (insulin, vaccines, enzymes),
transgenic animals (mice) for research.
o Principle of recombinant technology in bacteria:
1. Isolation of gene of interest
2. Modification of gene
3. Insert gene into vector
4. Insert vector into cells of organism that needs to be modified
- Atoms are the smallest (can’t be broken down)
- Molecules are 2 or more bonded atoms
- Ions are atoms or molecules that have positive or negative charge
- Proteins are large biomolecules (thus many atoms chemically combined)
- Enzymes are proteins (thus also biomolecules, and in turn many atoms chemically
combined) that act as biological catalyst; accelerate chemical reactions.
- DNA (Deoxyribonucleic Acid) = molecule, encodes ALL genetic information, is the
blueprint for all biological life. It is stored and passed on to the next generation.
- RNA (Ribonucleic Acid) = molecule, functions as the reader of the “DNA blueprint”
- Electrical Potential: potential is created by separation from + and – due to a
membrane.
- Voltage: measure of potential energy generated by separated charges. mV used for
neurons
- Electrical Current: the flow of electricity from one point to another. Current =
voltage/resistance. They indicate the flow of positively and negatively charge ions
across the resistance of your cells’ membranes.
Lecture 1
Exam will be open book, but no time really available to look things up.
Fast questions are not multiple choice, but one-word answers; hence, STUDY WELL.
Bacteria, cell, tissue (lowest order complexity): in vitro
Invertebrates, animals, human: in vivo (alive)
Computers (for simulation): in silico
90% of animals in research are Rodents (mainly rats and mice)
Only <1% cats, monkeys, etc.
Why? Small, cheap, short breeding cycles, relatively intelligent, agile, resistant to infection,
easy to handle. Have been used for long time, much data available.
Also; mice. They have convenient genetic manipulation.
Experimental Techniques
- Manipulation
o Lesions
o Electrical stimulation
o Pharmacological
o Genetic manipulation
o Behavioral manipulation
- Monitoring
, o In vivo:
Electrophysiology (electrical)
Micro-dialysis (chemical)
Behavioral evaluation (tasks)
o Ex vivo:
Histology
Immunohistochemistry
In situ hybridization for mRNA or DNA
Stereotaxic brain surgery
- For doing precise brain surgery
- Specific equipment for the species
- Holds the head in fixed position
- Three axes move the tip
- For lesions, microelectrodes, etc.
Stereotaxic brain atlas
- Represents 3D coordinates system of a specific species brain
- Bregma, Lambda are reference points
- “2.8 mm posterior to bregma, 4.5 mm lateral, 8.5 mm ventral to find amygdala” as
an instruction for finding the spot of interest.
Micro-dialysis
- Inner and outer tube; flow of liquid
- Like a blood capillary; semi-permeable; not all molecules can pass through
- Perfusate (inflow): salt solution, similar to brain tissue. Liquid flow must be 0 net
value (important!), otherwise liquid gets pumped or sucked into/from brain.
- Dialysate is outflow; which is monitored
- Allows for:
o Monitoring of chemical events in living tissue; gives temporal information
o Continuous drug delivery
o sample tissue chemistry with high accuracy and without taking blood
Electrophysiology (different levels)
- Single ion channel
o Patch clamp recording;
Records from single channel
microscope into tissue, probe close to surface of single cell, tiny bit of
suction sucks a seal onto cell.
Reference electrode is kept in a bath.
- Single unit (one cell)
o Intracellular recording;
sharp electrode penetrates cell membrane,
extracellular reference electrode in the bath that the cell is in.
Records voltage.
Moment of penetration the -70mV is visible on the oscilloscope.
Stimulation to cell can be done: hyperpolarizing the neuron by
, applying negative current. Depolarizing by applying positive current;
done until -55mV (firing threshold), an action potential occurs.
o Extracellular recording (also for multi-unit recordings);
can be done in vivo.
Reference electrode is ground.
Record electrode very close to cell.
In multi-unit: small bundle of electrodes; data analysis techniques can
derive different contributions to different cells.
- Multiple cell recordings (see extracellular recording)
- Field potentials (parts of tissue)
o Records synchronous activity from many cells; records synaptic transmission
o Done in vivo mainly.
o Records synchronous activity from many cells; from outside (extracellular
space).
o Negativity is left behind outside from the neuron.
o In vivo: stereotaxic procedure is used for implanting electrodes
- Brain potentials; EEG, etc.
o EEG; Electroencephalogram.
Larger parts of brain recorded.
Potential differences between electrodes are measured on the scalp.
They need to have similar spatial orientation.
Mainly gives out info from dendrites of cortical neurons.
EPSP’s or IPSP’s that are aligned in same orientation.
Minor to no contribution from action potentials; too scarce and don’t
have same direction. Mostly oscillating potentials; frequency bands
with different spatial distributions.
- Genetic Manipulation (genetic engineering, etc.)
o Direct manipulation of organism’s genes. Different than inbreeding strains
(like breeding dogs). Genetic manipulation is directly on the DNA;
spontaneous mutation. Every organism’s genes can mutate, can be adaptive
or maladaptive.
Transgene: foreign DNA that is inserted into host organism.
Transgenic Organism: the organism that will/is transformed with the
transgene.
o Possibilities: 1. Foreign DNA in the form of a plasmid, only in really simple
organisms; Prokaryotes (bacteria, viruses). 2. Foreign DNA integrated into
host genome (in mammals).
o Use:
modification of crops,
produce biomedical molecules (insulin, vaccines, enzymes),
transgenic animals (mice) for research.
o Principle of recombinant technology in bacteria:
1. Isolation of gene of interest
2. Modification of gene
3. Insert gene into vector
4. Insert vector into cells of organism that needs to be modified
