Unit 8

Question 1

Emotion

Answer 1

is any relatively brief conscious experience characterized by intense mental activity and a high degree of pleasure or displeasure.

Question 2

Valence, or hedonic tone

Answer 2

is the affective (mood-related) quality referring to the intrinsic attractiveness/”good”-ness (positive valence) or averseness/”bad”-ness (negative valence) of an event, object, or situation. The term also characterizes and categorizes specific emotions. For example, emotions popularly referred to as “negative”, such as anger and fear, have negative valence. Joy has positive valence. Positively valenced emotions are evoked by positively valenced events, objects, or situations. The term is also used to describe the hedonic tone of feelings, affect, certain behaviors (for example, approach and avoidance), goal attainment or nonattainment, and conformity with or violation of norms. Ambivalence can be viewed as conflict between positive and negative valence-carriers.

Question 3

Feedback from facial muscles

Answer 3

Emotions correspond to universal qualities of associated facial expression, and making theses expressions produce corresponding body responses like change in heart rate and skin temp.

Question 4

Neonatal imitation

Answer 4

We are pre wired to practice manipulating the muscles of emotional expressions based on the behavior of others.

Question 5

Emotional Arousal

Answer 5

describes the level of physiological activity, which is independent of the valence of the emotion.

Question 6

Schachter-Singer Theory, also known as the “two-factor theory” of emotion

Answer 6

states that 2 factors are needed to experience emotion. First, environmental stimuli elicits a physiological response. Second, we cognitively appraise this physiological activity, and try to give it the correct label.

Question 7

Learned helplessness

Answer 7

is behavior exhibited by a subject after enduring repeated aversive stimuli beyond their control. It was initially thought to be caused from the subject’s acceptance of their powerlessness: discontinuing attempts to escape or avoid the aversive stimulus, even when such alternatives are unambiguously presented. Upon exhibiting such behavior, the subject was said to have acquired learned helplessness. Over the past few decades, neuroscience has provided insight into learned helplessness and shown that the original theory actually had it backwards: the brain’s default state is to assume that control is not present, and the presence of “helpfulness” is what is actually learned. If prefrontal cortex is removed, it won’t learn this.

Question 8

Limbic system

Answer 8

is a set of brain structures located on both sides of the thalamus, immediately beneath the cerebrum and forming a border (=Latin ‘limbus’) around the brain stem. It is not a separate system but a collection of multiple structures. These structures are involved in the control of mood and attitude; are involved in storage of highly charged emotional memories; and in the control of appetite and sleep cycles.

Question 9

The Papez circuit (or medial limbic circuit)

Answer 9

it’s one of the major neural circuit/pathway in the limbic system involved in the control of memory and emotional expression. It begins and ends with the hippocampus. Dysfunction of this circuit underlies temporal lobe epilepsy.

Question 10

Hippocampus

Answer 10

Structure
 Stretches from middle of brain (below corpus callosum) down into the temporal lobes, ending adjacent to the amygdala
Functions
 Memory consolidation and retrieval
 Spatial memories
 Involved in emotion processing

Question 11

Fornix (Latin: arch)

Answer 11

is a C-shaped bundle of nerve fibers in the brain that acts as the major output tract of the hippocampus. Has a role in modulating general cognition and episodic memory recall. Damage to the fornix can affect some aspects of memory.

Question 12

Amygdala (plural: amygdalae; Latin: almond)

Answer 12

Structure
 is one of two almond shaped groups of nuclei (groups of cell bodies) anterior to hippocampus in medial temporal lobes in complex vertebrates
 Centromedial - autonomic functions
 Basolateral - conscious/arousal processing
Function
 Aggression, sex, stress
 Fear conditioning
 Memory consolidation
 Role in learning to associate object with reward/punishment.

Question 13

Centromedial nuclear group

Answer 13

Central nucleus is the major input to sympathetic nervous system; Stimulation causes smacking, salivation, licking and chewing movements, emptying of the bladder and rectum; increased food intake.

Question 14

Basolateral nuclear group

Answer 14

Stimulation causes arousal, attention, reduced feeding; Strong stimulation causes powerful rage. Also has a role in conditioned fear (e.g., startle reflex)

Question 15

Lateral Amygdala

Answer 15

Output to central gray area of midbrain; Part of tegmentum for motor control, esp. of neck muscles. Clenching these muscles helps protect fragile cervical neurons near surface during actions like the startle reflex. Output to hypothalamus (master hormone regulator) to influence autonomic nervous system responses like blood pressure and heart rate. Input from pain fibers/responses, sensory activity. Triggers startle reflex. Also involved in detecting and learning emotional associations with central and baso-lateral nuclei (info in the environment).

Question 16

startle reflex

Answer 16

is a brainstem reflectory reaction (reflex) that serves to protect vulnerable parts, such as the back of the neck (whole-body startle) and the eyes (eyeblink) and facilitates escape from sudden stimuli. It is found across the lifespan of many species.

Question 17

Post-traumatic stress disorder (PTSD)

Answer 17

an anxiety disorder in which patients have nightmares, flashbacks, increased arousal (sleeplessness, hypervigilance), depression, irritability, conditioned enhancement of startle reflex and avoidance of stimuli associated with a traumatic event such as war, rape, or assault. A new diagnosis of complex PTSD is now being used to describe PSTD symptoms that arise from an extended period of more mild/moderate stress, rather than from one very high stress event as is typically associated with PTSD.

Question 18

Possible causes of PTSD

Answer 18

 Alterations in baseline stress hormone levels (cortisol): initial differences in baseline cortisol levels may predispose individuals to PTSD
 Anatomical/functional differences in amygdala, hippocampus, prefrontal cortex
 Possibly maladaptive learning pathway to fear response through a hypersensitive, hyper-reactive and hyper-responsive hypothalamus-pituitary-adrenal axis [= major part of the neuroendocrine system that controls reactions to stress and regulates many body processes, including mood and emotion]

Question 19

Cholecystokinin (CCK)

Answer 19

is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein. Cholecystokinin, also called pancreozymin, is synthesized and secreted by enteroendocrine cells in the duodenum, the first segment of the small intestine. CCK plays important physiological roles both as a neuropeptide in the central nervous system and as a peptide hormone in the gut. It participates in a number of processes such as digestion, satiety (fullness), and anxiety. CCK is found extensively throughout the central nervous system, with high concentrations found in the limbic system. In both humans and rodents, studies clearly indicate that elevated CCK levels cause increased anxiety. The site of the anxiety-inducing effects of CCK seems to be central with specific targets being the basolateral amygdala, hippocampus, hypothalamus, peraqueductal grey, and cortical regions.

Question 20

CCK in amygdala

Answer 20

 CCK stimulates post synaptic cell, opening Na+ gates (increasing activity)
 Involved in learned enhancement of startle reflex

Question 21

CCK in hypothalamus

Answer 21

 CCK in hypothalamus suppresses hunger when blood sugar rises
 Some diet pills are CCK agonists, that mimic CCK effects (activate CCK channels)
 Side effect in amygdala = increased anxiety
 CCK antagonists can block receptor sites, without opening gates
 Has a calming effect but cause hunger (can promote over eating)

Question 22

Serotonin (5-HT) in amygdala

Answer 22

 Serotonin is released into post synaptic cell and once it’s bound it’s reuptaken whole into the pre synaptic cell
 This breaks serotonin apart and creates a metabolic byproduct 5-HIAA
 5-HIAA is disposed of into bloodstream by glial cells
 Low lv of 5-HIAA in bloodstream creates impulsivity and depression (marker of low serotonin)
 Anti depressants like PROSAC block serotonin reuptake by binding with the receptor, freeing available serotonin to re-stimulate the post synaptic cell (gives it more time to react with receptor and build up larger depolarization)

Question 23

GABA in amygdala

Answer 23

 GABA opens Cl- gates, inhibiting post synaptic cell (increased gaba = decreased activity and firing in amygdala) which helps to suppress startle reflex and reduces anxiety
 Anti anxiety drugs like Valium are GABA agonists enables GABA to bind more easily and for longer to receptor site at post synaptic cell, increasing its effectiveness (larger signal)

Question 24

Urbach–Wiethe disease

Answer 24

is a rare recessive genetic disorder that causes general thickening of the skin and mucous membranes. In some cases there is also a hardening of brain tissue in the medial temporal lobes, including calcification of the amygdala which impairs function. These amygdalar changes can cause impaired emotional responses, like a flattening of affect (limited mood range) and issues with interpreting emotions in other people.

Question 25

Klüver-Bucy syndrome

Answer 25

a syndrome caused by severe bilateral damage to the amygdala that is characterized by placidity, diminished fear responses, inability to recognize emotional importance of an event (memory problems), eating inappropriate objects, over-eating, hyper-orality, altered sexuality (compulsive sex drive, sex with inappropriate objects), visual agnosia (unable to recognize objects/faces), bulimia and hypermetamorphosis.

Question 26

Hypermetamorphosis

Answer 26

impulse to notice and react to everything within sight

Question 27

Klüver-Bucy syndrome Causes and Treatments

Answer 27

o Causes: Thought to be caused by damage to the amygdala (fear response region) of the limbic system and connections between limbic system and frontal cortex
o Treatments: not very good; they target symptoms and include antipsychotic meds to decrease dopamine.

Question 28

Cingulate gyrus

Answer 28

lies just above corpus callosum and plays a role in working memory
with severe long lasting anxiety, surgical lesions are sometimes made in anterior cingulate gyrus

Question 29

Anterior cingulate cortex (ACC)

Answer 29

 the anterior half of the cingulate gyrus is part of the limbic system and is divided anatomically based on attributed functions into executive (anterior), evaluative (posterior), cognitive (dorsal) and emotional (ventral) components.
 Connects with prefrontal, parietal, motor cortices and frontal eye fields
 Brodmann area 24, agranular
 It is involved in cognitive functions including: reward anticipation, error detection, decision making, empathy, and emotion. It also plays a role in a wide variety of autonomic functions like regulating blood pressure and heart rate.

Question 30

Posterior cingulate cortex (PCC)

Answer 30

 the posterior half of the cingulate gyrus. It’s made up of the BA 23, 31 (border belt) and granular
 It is less well understood than the ACC, but may have roles in autobiographical memory, episodic memory retrieval, the ‘default network,’ consciousness, and pain perception.

Question 31

Cingulum

Answer 31

is a collection of white matter fibers projecting from the cingulate gyrus to the entorhinal cortex in the brain, allowing for communication between components of the limbic system.

Question 32

Septal nuclei

Answer 32

 are a group of nuclei in the middle of anteroventral cerebrum.
 Made of midline structures (medial, lateral and posterior groups) that function as an important pleasure area.
 Electrical stimulation has an inhibitory effect on the autonomic nervous system, including cardiac deceleration. Septal lesions produce rage reactions in many species. This rage response appears to be defensive rather than aggressive.
 Nuclei receive reciprocal connections from the hippocampus, amygdala, hypothalamus, midbrain, habenula, cingulate gyrus and thalamus

Question 33

Nucleus accumbens

Answer 33

 is a collection of neurons within the forebrain near where the head of the caudate (part of the basal ganglia) and the anterior portion of the putamen meet just lateral to the septum pellucidum.
 It is thought to play an important role in reward, pleasure, laughter, addiction, aggression, fear, and the placebo effect.
 Two structures - the nucleus accumbens core and the nucleus accumbens shell

Question 34

Mammillary bodies

Answer 34

 are a pair of small round bodies located at the ends of the anterior arches of the fornix that act as a relay for impulses coming from the amygdalae and hippocampi via the mamillo-thalamic tract to the thalamus.
 Consists of two groups of nuclei, the medial mammillary nuclei and the lateral mammillary nuclei
 Often categorized as part of the hypothalamus
 They are involved with the processing of recognition memory, along with the anterior and dorsomedial nuclei in the thalamus. Damage to these causes anterograde amnesia (unable to form new memories) (e.g., patient N.A.; Wernicke-Korsakoff syndrome)

Question 35

Hormones

Answer 35

 Interaction is bidirectional
 are chemical messengers released from endocrine glands that travel through the blood system to influence the nervous system to regulate behaviors such as aggression, mating, and parenting of individuals. The study of this interaction is called behavioral endocrinology

Question 36

Hypothalamus

Answer 36

 Is a midline structure located on the floor of the brain, just behind the optic chiasm and above the pituitary gland.
 Considered to be the ‘final common path’ of emotional processing/master regulator of hormone’s in our body , it receives input from all sensory systems and its output plays a key role in releasing hormones to control the neuroendocrine network of the body, send output to various motor control nuclei and parasympathetic nervous systems.
 Sends both neuron and hormonal outputs to pituitary
 Is critical for regulating body temperature, maintaining daily physiological cycles, controlling appetite, managing sexual behavior, and regulating emotional responses. It consists of multiple nuclei that each control the release of different types of neurons.

Question 37

Pituitary gland (also called hypophysis)

Answer 37

is an endocrine gland/structure located just below and interconnected with the hypothalamus.

Question 38

Anterior pituitary (or adenohypophysis)

Answer 38

 is a lobe of the pituitary gland that regulates several physiological processes including stress, growth, reproduction, and lactation.
 It contains glandular epithelium (cells that produce and release hormones). It is connected to the hypothalamus via a hypophyseal portal vein system (a vascular system that connects two capillary beds).
 Hormones released by the hypothalamus travel through the blood in these veins to the anterior pituitary and then induce or inhibit the release of other hormones from the cells in the anterior pituitary, which are, in turn then released into the general blood stream

Question 39

Posterior pituitary (or neurohypophysis)

Answer 39

 consists of the direct extension of neurons extending from the supraoptic and paraventricular nuclei of the hypothalamus.
 This structure has a separate embryological origin than the anterior pituitary.
 The cells of the posterior pituitary have cell bodies in the hypothalamus and axons that run through the pituitary stalk (infundibulum) into the poster pituitary.
 Once within the pituitary region, the axons terminate on blood vessels, and thus release hormone’s directly into the blood stream. The posterior pituitary is thus basically an extension of the hypothalamic neurons.

Question 40

Intermediate lobe of the pituitary

Answer 40

is a thin layer of cells between the anterior and posterior pituitary lobes that produce melanocyte-stimulating hormone (MSH) – role in appetite, sexual arousal, and melanin production.

Question 41

Adrenal gland

Answer 41

is a small, conical organ on top of each kidney. These endocrine glands produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. Cortisol is a key hormone mediating the stress response.

Question 42

Hypothalamic–pituitary–adrenal axis (HPA axis or HTPA axis)

Answer 42

 is a complex set of direct influences and feedback interactions among three components: the hypothalamus, the pituitary gland, and the adrenal (also called “suprarenal”) glands. Together, these structures control reactions to stress and regulate many body processes, including digestion, the immune system, mood and emotions, sexuality, and energy storage and expenditure.
 Composed of two parts - the cortex and the medulla which are each responsible for producing different hormones