Science Section 5 Flashcards
In 2013, President Obama launched what initiative that focused on giving researchers a more dynamic picture of the brain?
Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative
How much funding was put into the BRAIN Initiative?
$46 million, beginning in 2014
What is the purpose of the Human Connectome Project?
to create the world’s largest map of neural circuit structure and function
What is connectome?
a map of the neural circuit structure and function within the human brain
BRAIN Initiative funding has resulted in…
- publishing a free and open atlas of the mammalian primary motor cortex and led to brand new microscopy technology
What are the two mechanisms used to study the brain since the early 20th century?
Perturbing and recording from the brain (using electrodes)
What is perturbing?
to alter the function of a biological system to see what changes will occur
Downsides of perturbing and recording from the brain
they are invasive techniques
What are noninvasive techniques?
refers to a medical procedure that does not require the introduction of instruments or foreign substances into the body
What are lesion studies?
studies conducted by removing or damaging a region/particular cell type in the brain to understand its necessity for a specific behavior
Are lesion studies ethical used on humans?
Nowadays, no
What is Broca’s Area?
region in the left frontal lobe that is critical to producing speech
Who was ‘Patient Tan’ ?
a patient with severely impaired speech because of a longstanding case of syphilis that damaged Broca’s area caused him to only be able to utter ‘tan’. His brain was examined by Paul Broca after his death.
What is electrical brain stimulation (EBS)?
the implantation of an electrode in the brain to stimulate specific neurons, neural networks, or brain regions in order to study the function of the cerebral cortex
Electrical brain stimulation has been used as early as the beginning of what century?
Nineteenth century
What is deep brain stimulation and what is it used as a treatment for?
using implanted electrodes as a treatment for Parkinson’s disease and tremors
Electroshock therapy
using electrodes on the scalp surface for treatment-resistant major depression
What is transcranial direct current stimulation (tDCS)?
a noninvasive technique that delivers a low electric current through the brain using one positive and one
negative electrode on the scalp; increases or decreases activity in particular regions of the brain
True or False? tDCS has been shown to have been shown to have a particular impact on humans during clinical trials
False because the stimulation it produces is so small (smaller than TMS and an implanted electrode)
What is optogenetics?
a method of controlling a neuron’s activity using light and genetic engineering (it introduces foreign genes that express the code for an ion channels that open or close in response to light)
What is channelrhodopsin-2 (ChR2)?
a type of opsin that also acts as an ion channel
What happens when the DNA sequence coding for ChR2 is artificially injected into neurons?
it is expressed as an ion channel that is sensitive to blue wavelengths of light. So if blue light is shone onto the surface of these neurons, the channel will open which allows sodium into the cell, thereby, depolarizing it. Neighboring neurons that didn’t get the gene have no response to the light
How is optogenetics and producing ChR2 using a DNA promoter that only works for certain neurons important?
Scientists can be very specific about which neurons they are targeting and stimulate or inhibit particular cells
What is transcranial magnetic stimulation?
a noninvasive technique that produces a magnetic field via an insulated coil placed on the scalp to alter the
activity of specific parts of the brain (some neurons will depolarize or hyperpolarize); can stimulate or inhibit a small, specific area of the brain without much spread; can be used to create a temporary or virtual “lesion” that prevents those neurons from performing their typical function for a short period of time
