Integrative Higher Brain Function: Learning, Memory, Language, and Interaction of CNS with Endocrine and Autonomic Nervo

1. Integrative Higher Brain Function: Learning/memory, language, and interaction of CNS with endocrine and autonomic nervous systems Metro AP Psychology Fall 2016 Stan Misler <latrotox@gmail.com>

2. 1. Plasticity: Learning and Memory • Learning (or learned behavior) is the acquisition of info as a consequence of environmental experience -> enhanced performance. It is distinct from innate behavior which is strictly controlled by genes and natural selection (e.g., infant ducks imprinting on and following first moving object it sees or wiggle behavior of bees to transmit to hive mates direction, location and quantity of nectar) • Memory: encoding, storage and retrieval of a memory trace (or engram) in different ways and places, based on release of glutamate in regions of hippocampus and cortex to suit different needs. Short-term working memory, where a small amount of data is stored for at most 100s of sec, is based on ongoing electrical activity in preformed synapses and it ceases with lapse into unconsciousness. Later consolidation to long term memory survives unconsciousness and cessation of electrical activity but requires synthesis of new protein, sprouting of nerve terminal boutons or elaboration of dendritic spines. Consolidation, by synaptic remodeling and pruning, occurs during rapid-eye movement interval of sleep cycles (brain picks out most salient info from day’s activities = “sleeping on it”). • Declarative memory: recall of conscious experience and surrounding events that can be put into words vs. procedural memory: unconscious recall of how to do

4. Where is memory trace or engram stored?Seminal case: surgical removal of amygdala and hippocampus as treatment of intractable epilepsy -> normal working memory and intelligence, normal procedural memory but not long term declarative memory

5. Accessing stored memory Recognition = association of physical object or event with something already experienced. Comparing present information with memory e.g., an “ace” test taker doing a multiple choice exam or identifying familiar face in a crowd Recall = remembering fact, object or event not currently present. Reconstruction of memory requires activation of all neurons involved in memory and its transfer into short-term working memory (e.g., taking an essay test which requires recalling much info often not used for a long time and need for thorough review )

6. 2. Language in thought, speech or writing • Association of arbitrary symbols with specific meanings for communication. Localized and lateralized in brain. Depends on integrity of specialized associative areas in temporal and frontal lobes of left hemisphere, which house verbal memories. • Language involves listening or reading, conceptualization of what to say or write, and then executing it using innate rules of grammar. Same areas used for sign language. However, recognition of emotional content of speech is function of right hemisphere. • Early damage to left hemisphere -> recruitment of right hemisphere for complexities of language Anatomy of speech

7. Broca’s aphasia Wernicke’s aphasia

8. 3. CNS Regulation of Whole Body Function a. Input to and output from hypothalamic paraventricular nucleus (PVN) -> complex visceromotor response • 1. PVN Activated by: • (i) olfactory bulb and the integrating limbic system (including the amygdala) (by feeding, pheromones and auditory and visual cues) • (ii) thalamic motor generator: jump started by "intended" as well as actual muscular effort. • (iii)vestibular afferents, carotid and muscle chemoreceptors, central respiratory generator (early Ds with exercise) • (iv) superfornical organ (SFO) area postrema with an open blood-brain barrier, responding to D circulating pH, pCO2, [angiotensin II]. • 2. In turn, PVN activates: • central respiratory drive generator • hypothalamic-pituitary-adrenal axis (CRF) • ADH release • central motor limb of the baroreceptor reflex for control of vasomotor responses • and deactivates: vegetative functions (digestive)

9. Closer Anatomical View: Hypothalamic nuclei and pituitary

10. b. Function of autonomic nervous system Relaxing after fright; rest and digest The autonomic nervous system, with its parasympathetic (acetylcholine releasing) branch and its sympathetic (noradrenaline releasing) branch, modulates involuntary (or vegetative) functionsof most internal organs. It does thisvia (i) alteringcontraction of smooth muscle of gut and blood vessel as well as heart muscle and (ii) stimulating or inhibiting fluid secretion by exocrine glands and hormone secretion by endocrine glands. Sympathetic branch acts as accelerator to mobilize body for action and output of energy while parasympathetic branch acts as brake that slows body down after acceleration and keeps it running smoother Fright, flight or fight

11. c. Central role of amygdala in "fright, fight or flight response" = “visceromotor " + "behavioral” responses a) Amygdala -> locus coeruleus: CNS arousal (EEG activation), startle reaction and increased vigilance b) Amygdala -> brain stem nuclei : pupillary dilation, facial expressions of rage or fear c) Amygdala -> thalamocortical pathways: motor behavioral responses (crouching, stalking) Rage (fight) vs. fear (flight) response depends on amygdala’s assessment of prospective outcome based on life experience

12. d. CNS Regulation of activity of endocrine system & endocrine feedback on CNS function 1. Body’s blood borne chemical messenger (or endocrine) system releases hormones (modified amino acids, peptides, and steroids) into the bloodstream from where they are filtered into interstitial fluid and then bind to and affect peripheral tissue. 2. Endocrine “messages” tend to work slowly (over minutes) using cell membrane G-protein coupled receptors to set off a cascade of cytoplasmic second messengers and/or cytoplasmic and nuclear receptors to increase synthesis of specific proteins; they outlast the effects of neural messages (working over sec at longest). 3. Under normal (unaroused) conditions, the endocrine system works in parallel with the parasympathetic nervous system to sustain our baseline body processes. In crisis, the endocrine system shifts into a new mode to support the sympathetic nervous system….it releases epinephrine (adrenalin) which triggers the “fight or flight” response

13. 4. Hormones also feedback on CNS where they modulate interest in sex and food, help control aggression and regulate adult neurogenesis, the life and death of neurons. Glucocorticoid excess reduces synaptic plasticity by promoting withdrawal of dendritic processes of neurons, while estrogen does the opposite. Hence moderately high levels of estrogen in blood help reduce the severity of a neurological insult caused by low oxygen or glucose levels of blood, while high concentration of corticosteroids worsens outcome of insult 5. Hormones do not cause behavior but play on pre-existing tendencies (lower pain threshold)

14. e. Secretory Organs of the Endocrine system • Pineal (1) secretes melatonin for circadian rhythm • Hypothalamus controls anterior pituitary gland and secretes from its nerve endings in posterior pituitary both vasopressin (antidiuretic hormone) and oxytocin (for uterine contraction during childbirth, ejection of milk while nursing and promotion of attachment) • Anterior Pituitary (2) secretes thyroid stimulating hormone that regulates thyroid secretion of thyroxine and ACTH regulating steroid production in adrenal cortex. At puberty it secretes LH and FSH to promote (a) testosterone secretion by testes (-> growth of testes and penis and secondary sex characteristics = deepening voice, body hair) or (b) estrogen and progesterone secretion by the ovary -> development of breasts and menarche (menstrual cycles) but only after acquisition of stores of body fat. Also secretes growth hormone that stimulates bone and muscle growth • Thyroid (3) effects cell metabolism • Parathyroids (3), embedded in thyroid, regulate serum Ca levels • Adrenal medulla (5) secretes catecholamines as back up for sympathetic nervous system • Adrenal cortex (5) secretes corticosteroids as part of a long lasting stress response • Pancreas (Islets of Langerhans) (6) secrete insulin and glucagon for push-pull response in regulation of serum glucose • Testes/ovaries (7,8) secrete male/female sex hormones

15. 4. Emotions & Emotional Motor System Emotional processing is part of complex brain function. It involves: (i) physiological changes in facial expression and brain and body functions, (ii) cognitive processing for interpretation of events and (iii) cultural influence that shape display rules (or body language) for response To review, for example, a treat which evokes fear invokes fast physiological and behavioral responses by the following series of events : (i) stimulation of reticular activating system in brainstem or cortical neurons -> (ii) activation of limbic system (amygdala) -> (iii) activation of hypothalamus (paraventricular nucleus, PVN). The latter has two effects (a) recruitment of sympathetic autonomic nervous system to evoke the complex visceromotor response and (b) recruitment of endocrine system for release of epinephrine and corticosteroids by adrenals. This fast initial response (i) can be modified or overridden by slower but more complete appraisal by prefrontal cortex (executive function) and (ii) can be consolidation as memory by hippocampus to be used for comparison with later “emotional” stimuli

16. a. Complexities • Role of facial expression: (a) communicates emotion to observers that could be contagious (infant reads mother’s face to decide whether fall should be alarming or passed over) (b) identifies own emotion by feedback to limbic system (put on angry face and heart rate speeds up). • Stressors that most commonly effect body are social stressors = problems at work, bereavement, constant noise, poverty and powerlessness. Shaping response to such a stressor depends on: previous medical and social history; genetic predisposition to chronic disease; optimism (belief that difficulty can be overcome) vs. pessimism; feeling of control over circumstances

17. b. Emotional style and coping Resilience = rate of recovery from setback or loss (a function of connectivity between prefrontal cortex and amygdala) depends on: • Outlook: capacity to sustain positive emotion over time • Social intuition: sensitivity to emotional states of others • Self-awareness: awareness of our own physiological and emotional cues • Sensitivity to context: awareness of social environment and sensitivity to rules of social engagement • Attention: the ability to focus attention and screen out emotional distractions Aids to coping: benefits of confession (communicating worrying thoughts; forgiveness of aggressor (“letting go”, “He who pursues revenge should dig two graves”) and rethinking problem; relaxation training; exercise; massage

18. 5. Stress • Physical, emotional and behavioral response to situations that are threatening or require changes in pattern of life: acute and brief stress disorder (with hassles) vs. ongoing PTSD. • Hans Selye, stress, and psychosomatic medicine: 3. New field of Health psychology: • investigation of how physical activities, psychological traits, social relationships, food and drug consumption, poverty, ethnicity and religious beliefs affect health and rate of recurrence of illness. • Promoting health through food, exercise, socialization, regularization of sleep pattern, management of time, management of anxiety/panic • Use of social readjustment rating scale as predictor of getting ill or having an accident due to distraction

19. a.Adaptive and Maladaptive Stress Responses (a) Features of acute adaptational stress : “turn on” of sympathetic autonomic nervous system by hypothalamic paraventicular nucleus + rhythmic ventilatory controller. Eustress =optimal amount of stress to promote high level function (b) Features of chronic maladaptational stress (1) Behavioral deactivation e.g., disordered gonadotropin response (young female athletes’ triad = underweight and short stature, delayed menarche or amenorrhea, decreased bone mineralization) (2) Slow disorganization of visceromotor program (e.g. disordered vascular regulation, decrease in blood flow to gut mucosa -> susceptibility to bacterial and endotoxin invasion -> increased susceptibility to multi-organ system failure (3) Persistent ACTH and cortisol release -> Catabolism, immunosuppression (4) Depression = “fog over the mind” “dulled personality”. Accompanied by atrophy of hippocampus = area of plasticity in learning and highest density of corticosteroid receptors -> (?) premature dementia (c ) General adaptive syndrome in response to continuous stress (catastrophes): alarm, resistance (analgesia to lessen alarm), exhaustion (decreased body reserve of glucose, decreased immune response, muscle fatigue, increased risk for heart attack & stroke)

20. Home Study 1. Localizing origin of language components using PET scanning

21. 2. Brain-Heart Connection: poor heart contraction under extreme stress No angiographic evidence of fixed vascular lesion or spasm –induced blockade; akinetic apex Like panic-induced asthma attack of the heart

22. 3. Inhibitory influences