Behavioral Neuroscience Exam 2

Emotions

subjective mental state that is usually accompanied by distinctive behaviors, feelings, and involuntary physiological changes

autonomic nervous system

activation of this system elicits physical sensations that relate to emotions

sympathetic nervous system

"fight or flight" system; prepares the body for action

parasympathetic nervous system

prepares the body to relax and recuperate

core set of basic emotions

-joy/sadness

-affection/disgust

-anger/fear

-expectation/surprise

darwin’s claim about emotional expression

may have originated from a common ancestor, and that nonhuman animals show comparable emotional expressions

8 distinctive emotional expressions

anger, sadness, happiness, fear, disgust, surprise, contempt, and embarrassment

Darwin’s reasoning regarding emotional expression

highlighted the appearance of facial expressions, as well as pointing out that facial muscles and innervation patterns are the same

evolutionary perspective of emotions

Emotions act as motivational programs that evolved to coordinate responses to solve adaptive problems

facial feedback hypothesis

suggests that sensory feedback from our facial expressions can affect or mood

example of facial feedback hypothesis

People performing a task who take on a happy or sad face report stronger feelings of the emotions they were simulating.

effect of botox injections on emotions

paralyze facial muscles => cause people to experience emotions less intensely

There is _____ simple, one-to-one relation between a specific emotion and charged activity of a particular brain region

NO

the limbic system in relation to emotions

different patterns of activation across a network of brain regions associated with emotion

emotions are associated with bilateral changes in…

the insula, amygdala, caudate, putamen, cingulate cortex, and prefrontal cortex activity

fear conditioning

A type of classical condition where a previously neutral stimulus is repeatedly paired with an unpleasant experience, causing the subject to act fearfully in response to the previously neutral stimulus

fear conditioning helps researchers identify…

important brain mechanisms involved in learning, memory, and threat detection

rapid changes that occur during fear conditioning highlight…

brain plasticity that is important for learning and fear

Exploring these neural circuits (limbic system) can help researchers develop therapies for treating…

anxiety disorders and PTSD

structures important in fear conditioning

amygdala, hippocampus, cortex

learned fears are notoriously ____ to extinguish the learned behavior

SLOW

damage to this area causes people to have little to know fear

amygdala

Love (compared to friendship) results in increased activity in the…

insula, anterior cingulate cortex, caudate, and putamen

Love (compared to friendship) results in reduced activity in the…

posterior cingulate, amygdala, and right prefrontal cortex

stressor

anything that disrupts the physiological balance in an organism

types of stressors

Environmental, Physical, Immunological, Psychological

the stress response is the brain’s adaptations designed to aid in…

survival in response to a threat or perception of a threat or perception of a threat

Types of stress responses

Neuroendocrine, immunological, behavioral

allostasis

The brain carefully monitors and controls stress responses and adjusts physiological parameters to accommodate current or anticipated stressors

allostatic load

Continually adapting to stressors incurs costs—energy expenditure, tissue damage, vulnerability to disease

FAST stress-activated pathway

“fight or flight” response => hypothalamus activates the sympathetic nervous system to cause the adrenal medulla to release epinephrine (adrenaline) and norepinephrine (noradrenaline)

SLOW stress-activated pathway

The hypothalamic-pituitary-adrenal (HPA) axis => The hypothalamus releases CRH (corticotropic releasing hormone), which acts on the anterior pituitary. The pituitary then releases ACTH (adrenocorticotropic hormone), which causes the adrenal cortex to release adrenal steroid hormones such as cortisol to ready the body for action

Stress-related disease

appears when the stress-response is activated for too long or too frequently, and when it is not activated for a physiological reason (e.g., psychological or social stresses)

People with happy social lives and lower stress are _______ to develop a cold when exposed to the virus

LESS LIKELY

People exposed to viruses have __________ symptoms if they are experiencing conflict with someone

MORE SEVERE

Individuals who feel they have more social support exhibit less severe symptoms and produce __________________ in response to a flu vaccination

MORE ANTIBODIES

relations of the nervous, endocrine, and immune systems

Psychological Factors in Stress and Coping

control, predictability, outlet for frustration, social support, personality

Psychological factors in stress and coping: CONTROL

As long as there is (even an illusion of) control over the occurrence of a stressful event, stress (and thus glucocorticoid levels) remains low

Psychological factors in stress and coping: PREDICTABILITY

Unpredicted, and thus unexpected, stressors are more stressful than predicted stressors

Psychological factors in stress and coping: OUTLET FOR FRUSTRATION

If there is an outlet for frustration (e.g., a piece of wood to gnaw on or a conspecific to attack), ulceration likelihood and glucocorticoid levels remain low under stress

Psychological factors in stress and coping: SOCIAL SUPPORT

Other things being equal, isolated animals show stronger stress responses to a stressor than group-housed animals (this is also true in humans!).

Psychological factors in stress and coping: PERSONALITY

What is stressful, depends on the goals of the organism (e.g., dominance, affiliation) and on genetically determined differences in overall fearfulness.

early life stress

chronic activation of the stress response early in life => Known to “scar” the brain and reshape mental health trajectories

Example of early childhood stressors

Adverse Childhood Experiences (ACEs)

Example of postnatal early live stressors

The longer the child spent in the orphanage, the higher their resting glucocorticoid level (even after getting adopted!)

example of prenatal early life stressors

Fetuses ”learned” about food availability during this famine, resulting in babies that were born having severely altered metabolism and increased risks of metabolic disorders such as diabetes, heart disease, obesity, and unhealthy cholesterol profiles

maternal immune activation (MIA)

Maternal infections can negatively alter typical neurodevelopment => Byproducts of the immune system activation can make their way into the embryo

Plays a vital role in autism spectrum disorder

Environmental pollution and stress play a vital role in development and diagnosis

early life stress and resilience

A large chunk of children faced with adversity develop adaptive coping strategies

stress is adaptive

Coping strategies can help reframe psychological stressors

Evolutionary neuroendocrinology

The study of how neuroendocrine systems arose and changed over time

Comparative neuroendocrinology

the study of how neuroendocrine systems are similar/different throughout the animal kingdom

Types of adrenal corticosteroids

Glucocorticoids, mineralocorticoids

Glucocorticocoids

“classic” stress response, bind to glucocorticoid receptor, e.g. cortisol/corticosterone

mineralocorticoids

blood pressure/osmolarity, bind to mineralocorticoid receptor, e.g. aldosterone

similarities between glucocorticoids and mineralocorticoids

derived from cholesterol, secreted from the adrenal cortex, exert effects via transcriptional regulation

measure glucocorticoids

types of samples: blood, saliva, fur/hair, urine, feces

outward markers of stress

repetitive behaviors, lethargy, weight loss or gain, aggression

Baseline circulating glucocorticoids are ______variable

HIGHLY

Circadian regulation

Cortisol/corticosterone peaks around the time of awakening and is lowest in the middle of the inactive (sleeping) phase

Circannual regulation

Day length modulates daily glucocorticoid rhythms Shorter days → sharper peak at beginning of waking phase

Monogamous animals may have evolved different behavioral and physiological adaptations to stress

higher circulating glucocorticoids than their promiscuous counterparts, behavior is more exploratory, and they seem to be more resilient to stress

If the predicted environment matches the actual future environment (“match”), this ______the individual’s fitness

IMPROVES

Telomeres

Repetitive sequences located at the ends of chromosomes => They protect DNA from degradation

adrenal fatigue

prolonged and severe stress that their adrenal glands stopped producing CORT altogether!

Sensory receptor organs

organs specialized to detect a certain stimulus

Receptor cells within sensory receptor organs

convert the stimulus into an electrical signal

adequate stimulus

type of stimulus to which a sensory organ is particularly adapted

ex: photic (light) energy detected by the eye

Sensory organs are very diverse, but all senses have the same end point:

converting information to neural signals

sensory transduction

conversion of energy from a stimulus into a change in membrane potential in a receptor cell

The doctrine of specific nerve energies states that

Receptors and neural channels for different senses are independent

labeled lines

The brain recognizes distinct senses because action potentials travel along separate nerve tracts

→ Neural activity in one line signals sound, activity in another line signals smell, and another line signals touch

receptors in skin

properties of skin receptors

Pacinian corpuscle

skin receptor that detects vibration and pressure

A stimulus to the corpuscle opens stretch-sensitive sodium channels made of a protein called Piezo, and produces a _____________ receptor potential (or generator potential)

GRADED

When the potential is big enough, the receptor reaches ________ and generates an action potential

→ only if AP generated do you detect the touch

THRESHOLD

Stimulus ________________ is determined from the position of the activated receptors

LOCATION

The action potentials produced by a sensory neuron always have the same size and duration, so one way the intensity of sensory events are encoded is in _____________ and ___________ of action potentials

NUMBER; FREQUENCY

range fractionation

Some sensory systems employ multiple sensory receptor cells that specialize in one part of a range of intensities; as the strength of a stimulus increases, more neurons sensitive to higher intensities are recruited

adaptation

progressive loss of response to a maintained stimulus

Phasic receptors

display adaptation and decrease frequency of action potentials with constant stimulation

tonic receptors

show slow or no decline in action potential frequency

Sensory systems emphasize ____________________, as that is more important for survival; prevents the nervous system from being overwhelmed by too much info coming in

CHANGE IN STIMULI

Control Incoming Information

Accessory structure, i.e. eyelids

Top-down processing

top-down processing

higher brain centers (like the cortex) suppress some sensory inputs and amplify others

dorsal column system

delivers touch information to the brain

→ receptors send projections via the dorsal column of the spinal cord, where they synapse on dorsal column nuclei in the medulla (brain stem)

stimulus triggers the _______ of a neuron

receptive field

Axons from neurons in the medulla _______ and go to the _______ for initial processing, and then on to the _______

cross the midline; thalamus; primary somatosensory cortex

the brain processes touch information from the __________________ side of the body

contralateral

The receptive field is the region in which a stimulus will alter a sensory neuron’s ________________

firing rate

Receptive fields differ in_________ to types of stimulation

size, shape, and response

→ To determine what touch a cortical neuron responds to, you can record from the cell and touch different parts of the body

→ The cell will fire when you touch the area it responds to, after following the dorsal column pathway and ending in the primary somatosensory cortex

The more neurons in the cortex dedicated to that area = the _____ the receptive field = the ____ that body part is at detecting touch

SMALLER; BETTER

The cortical map represents…

the distribution or supply of nerves to a specific body part, organ, or muscle of a body region

Neuron number dedicated to a region can be changed by _______

experience

Intentional stimulation of a specific body region can _____________ its cortical representation Loss of use will cause it to _____________

EXPAND; SHRINK

Phantom limb explains the plasticity of somatosensory representations

pain

An unpleasant experience associated with tissue damage