Bio Sci Questions & Answers Interlude #1

Do different parts of your brain control
different behaviors, or is it a homogenous
mass of tissue?

Different parts for different behaviors

What’s the easiest way to solve the question: ‘Do
different parts of your brain control different
behaviors, or is it a homogenous mass of tissue?’

Examine people who have parts of their brain
missing and see what functions are lost.

Lobotomies sever the connection between the
entire frontal lobe to the thalamus. The
thalamus act as a relay center for sensory
systems. What do you think this does to a
patient’s behavior?

Mummified calmness

What is the function of Broca’s area? (Remember that ‘Tan-Tan’ guy)

Language production AND Language Comprehension

What can we conclude about brain connectivity required for brain function?

Regions receive input from other regions which sends projections to other regions based on their function.

DSM-V = The Diagnostic and Statistical Manual of Mental Illnesses —> Used to diagnostic mental disorders. Currently, how are mood disorders diagnosed?

Self-Report of Behavior

According to the monoamine hypothesis of depression. Which of the mechanisms below would cure depression?

Force norepinephrine to stay in the synapse between the two neurons.

How long is an axon?

Depends on the neuron. By they range from a few millimeters to as long as a meter, with the longest axons in the human body being those of the sciatic nerve, which run from the base of the spinal cord to the big toe, reaching up to a meter in length

What protein does antidepressants target?

They primarily target the serotonin transporter protein (SERT), which is responsible for reabsorbing serotonin in the brain, by blocking its function and increasing the availability of serotonin in the synaptic cleft; this is particularly true for drugs classified as selective serotonin reuptake inhibitors (SSRIs).

What are lesion studies?

A research method which examines effects of brain damage on behavior and cognition. May shed light on how specific brain regions support complex cognitive constructs like personality, morality, aesthetic valuation, and insight which can help identify the functions of different brain areas.

What is phrenology?

A study of the skull’s contours to predict a person’s mental traits and character-the study of shape and size of the cranium as a supposed indication of character and mental abelites.

Without the cerebellum what occurs?

Animals lost their muscle coordination and sense of equilibrium. Which means that if it is removed from a person, the person will have difficulty with balance and movement: slanted walking, and overshot movements. Function: Sends signals for the body to adjust and move —> Coordination, maintain balance and posture

Without the medulla oblongata what occurs?

Animals may experience loss of vital autonomic functions such as breathing and heart rate regulation.

Is phrenology a real thing?

It is considered a pseudoscience that lacks empirical support and scientific validity. (Debunked by Jean Pierre Flourens)

Which region of the brain is responsible for executive function

Frontal Lobe-The region of the brain responsible for planning, decision-making, and impulse control.

Egas Moniz and Walter Freeman

Invented lobotomies —> “Treated mental disorders”

What are lobotomies, what do they do?

They sever the connection between the frontal lobe and the thalamus.

They are quick, (widely) given to stop psychosis and children’s temper tantrums. Sometimes calmed psychosis, but did make patients mentally dull.

What does the thalamus do?

It is the relay center for sensory systems. An area of the brain that helps process information from the sense and transmits it to other parts of the brain.

What is psychosis?

A collection of symptoms that affect the mind, where there has been some loss of contact with reality. During an episode of psychosis, a person's thoughts and perceptions are disrupted and they may have difficulty recognizing what is real and what is not.

What does the overarching principle of Structure —> Function mean?

A structure’s physical characteristics influence its interactions with other structures —> And therefore it’s functions.

When it comes to the overarching principle of Structure —> Function, which is true:

A) Physical attributes shape function

B) A particular brain structure has a particular function.

A) Physical attributes shape function

Increased rostral anterior cingulate cortex (rACC) theta activity linked to better antidepressant (sertraline) outcomes.

What is rACC and what is sertraline?

rACC: part of the brain that integrates emotions and cognition

Sertraline: increases level of a mood, which enhances chemical serotonin in one’s brain (increases serotonin)

Serotonin is a type of neurotransmitter, what is a neurotransmitter?

A main type of chemical messenger in the brain. Released from one neuron to communicate with a second neuron.

What are neuropeptides and peptides?

Neuropeptides: Another type of chemical messenger.

Peptides: are much larger than neurotransmitters

What are the similarities between neuropeptides and neurotransmitters?

They are involved in chemical transmission but they differ from electrical transmission

What is electrical transmission?

The process by which neurons communicate with each other through electrical signals, primarily via action potentials that travel along the axon of a neuron, allowing for rapid information transfer and ultimately influencing behavior by triggering the release of neurotransmitters at the synapse with other neurons. Essentially, it's the electrical activity within the brain that underlies all thought, feeling, and physical action.

What is going on when it comes to serotonin being released into the synapse?

It is the space between 2 neurons = synapse

Sertraline (Sold as the trade name Zoloft) ____ serotonin in the brain

Increases!

What is the name of the process by which neurotransmitters are released from the presynaptic neuron?

Exocytosis

Exocytosis is a cellular process in
which substances ________________
via vesicles.

Released from the cell

Endocytosis is a cellular process in
which substances _______________
via vesicles.

Brought into the cell

Botox inhibits vesicles from fusing to the plasma membrane by inhibiting snare proteins. What does botox do to neural transmission?

Blocks exocytosis

What is the fiber of EFFERENT?

Motor nerve fiber which carries impulses away from the central nervous system (CNS) to effector organs (muscles/ glands). Also known as motor fibers!

Information flows FROM the brain and spinal cord (MOTOR INFORMATION)

What is the fiber of afferent?

A nerve that carries sensory info from the body to the central nervous system

Information flows TO the brain and spinal cord - SENSORY INFORMATION

what part of the sensory fiber is in your bigtoe? Axon terminal or dendritic spine?

Axon terminal

What occurs during the exocytosis process?

Vesicle fusion

What occurs during the endocytosis process?

Vesicle separates from the plasma membrane

Dynamin mutants are missing a protein called dynamin. In these mutants, the vesicles cannot split from the plasma membrane. What happens to synaptic transmission?

Blocks Endocytosis

Dynamin mutants have _____. Vesicles can fuse to the plasma membrane but are stuck at the plasma membrane.

A characteristic where they are unable to fully detach and pinch off from the plasma membrane.

What in the world is dynamin?

A type of protein that plays a key role in membrane remodeling and fusion.

What is the function of dynamin?

Plays a vital role in clathrin-dependent endocytosis and other vesicular trafficking processes by acting as a pair of molecular scissors for newly formed vesicles originating from the plasma membrane.

What is electrophysiology?

Branch of neuroscience that studies the electrical activity of neurons.

Why is the typical postsynaptic response so much larger than the response to a single vesicle?

There are multiple vesicles fusion events concurrently.

What do exocytosis and endocytosis have in common?

They recycle membrane

What do uptake transports do to neurotransmitters?

Uptake transporters recycle neurotransmitters

Interlude on what chemical transmission
is not what?

Action potential

What do electrical impulses go through a neuron?

Because of differences in ion concentrations. Resulting in a voltage difference, called a “potential”

The difference in electrical charges
inside and outside a cell creates what?

Voltage difference —> MEMBRANE POTENTIAL

What causes the voltage difference (also known as potential) across the membrane?

Difference in ion concentration

When a neuron is at rest, there is a
voltage difference across the
membrane. What do we call this?

Resting membrane potential

When an electrical impulse is traveling
down a neuron, what do we call this?

Action potential

What happens when K^+ channels open?

Hyperpolarization of the membrane potential
towards equilibrium potential for potassium (E k)

How is current carried in a neuron?

Charged ions

Considering that the inside of the cell starts very negative, what are the characteristics of an action potential?

Quick Depolarization

Why do you have to eat Fugu w/ caution?

It contains tetrodotoxin (TTX) which blocks v-gated Na^+ channels

Tetrodotoxin (TTX) blocks voltage-gated sodium channels. What does TTX do to neural transmission?

Blocks action potential