Foundations of Behavioral Neuroscience PDF

10/9/24, 4:15 PM Foundations of Behavioral Neuroscience 🧠 2.pdf Foundations of Behavioral Ne uroscience 2.pdf 🧠 Motivation and Behavior Overview of Motivation Mo...

10/9/24, 4:15 PM Foundations of Behavioral Neuroscience 🧠 2.pdf Foundations of Behavioral Ne uroscience 2.pdf 🧠 Motivation and Behavior Overview of Motivation Motivation refers to the factors that initiate, sustain, and direct beha vior (e.g., feeding, fleeing, fornicating) (Motivation Overview) Key theories of motivation include: Instinct Theory: Automatic, unlearned behaviors, like infant behavio rs such as breastfeeding (Instinct Theory) Drive Theory: Motivation in terms of needs arising from physical co nditions, where a change in internal state prompts a behavior to re store balance (Drive Theory) Homeostatic Drive: A "control system" that maintains conditions ar ound a set point, regulated by the hypothalamus (Homeostatic Dri ve) Incentive Theory: People motivated by external stimuli, like money or good grades (Incentive Theory) Arousal Theory: People behave to satisfy a certain level of sensatio n, which can be hardwired or learned (Arousal Theory) Key Brain Regions and Neurotransm itters Dopamine signals reward, with highest levels during orgasm to pro mote reproduction; also regulates movement patterns in the basal ganglia (Dopamine) Hypothalamus regulates body hormones, with the pituitary gland ta king commands and signaling the brain to respond accordingly (Hy pothalamus and Pituitary Gland) Pineal gland regulates sleep and daily/seasonal cycles of behavior t hrough hormone release (Pineal Gland) Taste and Feeding Behavior Primary taste sensations: sweet (carbohydrates/energy), salty (ions for neural transmission), sour (spoiled/acidic food), bitter (toxic che micals), umami (protein content) (Primary Tastes) about:blank 1/4 10/9/24, 4:15 PM Foundations of Behavioral Neuroscience 🧠 2.pdf Taste pathway: Taste buds -> Nucleus of the Solitary Tract (NST) -> T halamus -> Gustatory Cortex (Taste Pathway) Learned taste aversion, learned taste preference, and sensory-speci fic satiety influence feeding behavior (Taste Behaviors) Key Players in Hunger Regulation Arcuate Nucleus (ARC): Integrates information about nutrient levels and sends signals to the hypothalamus (ARC) Lateral Hypothalamus: Initiates eating and controls feeding behavior s and metabolic responses (Lateral Hypothalamus) Paraventricular Nucleus (PVN): Regulates eating and metabolic proc esses like body temperature, fat storage, and cellular metabolism (P VN) Ghrelin: Stomach-derived hormone that increases appetite when le vels are high (Ghrelin) NPY: Neuropeptide released by the ARC that increases appetite (NP Y) PYY: Intestine-derived peptide that suppresses appetite (PYY) CCK: Stomach and small intestine-derived peptide that decreases meal size (CCK) Vagus Nerve: Direct connection from liver to brainstem that signals hunger and satiety (Vagus Nerve) Hunger Pathways Liver Pathway: Liver detects blood nutrient levels, signals the vagus n erve, which then signals the NST and ARC to stimulate feeding (Liver Pathway) Stomach Pathway: Stomach detects fullness, releases ghrelin into th e bloodstream, which then signals the ARC to stimulate feeding (Sto mach Pathway) Satiety/Stop Signals: Stomach stretch receptors, decreased ghrelin -> Vagus nerve -> N ST -> Inhibits Lateral Hypothalamus Small intestine stretch, CCK release -> Vagus nerve -> NST -> Inhibi ts Lateral Hypothalamus Large intestine releases PYY -> ARC -> Inhibits NPY Fat cells release leptin -> ARC -> Inhibits NPY (long-term) Sex and Reward Similar to hunger and thirst, with arousal, motivation, and hormonal control (Sex Overview) about:blank 2/4 10/9/24, 4:15 PM Foundations of Behavioral Neuroscience 🧠 2.pdf Dopamine is the neurotransmitter involved in the reward of sex, with maximum levels during orgasm (Sex and Reward) Key hormones: Oxytocin: Promotes sexual arousal and social bonding, produced i n the hypothalamus and released by the pituitary gland (Oxytocin) Testosterone: Primary male sex hormone, produced in the testes a nd adrenal glands (Testosterone) Estrogen and Progesterone: Primary female sex hormones, produc ed in the ovaries (Estrogen and Progesterone) Brain Regions Involved in Sex Medial Preoptic Area (MPOA) of the hypothalamus: Deals with sexual performance and instinctual sex behavior (MPOA) Medial Amygdala (temporal lobe): Involved in the emotional and be havioral aspects of copulation (Medial Amygdala) Ovulation and Pheromones Ovulation is the peak time for females to mate, as they are most likel y to pass an egg (Ovulation) Pheromones are chemicals released into the environment that affec t another individual's behavior; detected by the vomeronasal organ (VNO) which connects to the MPOA and amygdala (Pheromones) Emotion Emotions involve physiological, cognitive, and behavioral reactions, expressed through facial expressions and pheromones (Emotion) The autonomic nervous system controls instinctual emotional beha viors: Sympathetic nervous system: "Fight or flight" response, releases cor tisol (Sympathetic NS) Parasympathetic nervous system: "Rest and digest" response, redu ces activity and conserves/restores energy (Parasympathetic NS) Negative emotions like fear are important for survival, while positive emotions enhance group communication and well-being (Negative and Positive Emotions) Mirror neurons allow us to empathize and imitate the emotional resp onses of others (Mirror Neurons) Stress and Aggression Cortisol is released in response to stress and provides negative feed back to moderate the stress response (Cortisol) about:blank 3/4 10/9/24, 4:15 PM Foundations of Behavioral Neuroscience 🧠 2.pdf The Periaqueductal Gray (PAG) modulates the peripheral response t o stress via input from the periphery and limbic system (PAG) Chronic stress can damage the hippocampus and gray matter (Chr onic Stress) Aggression is behavior intended to create distance or impose harm between two individuals, and can be either predatory (attack and kil l) or affective (emotional, unprovoked) (Aggression) Table: Key Brain Regions and Their Functions Brain Region Function Arcuate Nucleus (AR Integrates information about nutrient levels and C) signals the hypothalamus Lateral Hypothalam Initiates eating and controls feeding behaviors a us nd metabolic responses Paraventricular Nucl Regulates eating and metabolic processes eus (PVN) Medial Preoptic Are Deals with sexual performance and instinctual s a (MPOA) ex behavior Involved in the emotional and behavioral aspect Medial Amygdala s of copulation Periaqueductal Gra Modulates the peripheral response to stress y (PAG) about:blank 4/4