Chemical Control of the Brain and Behavior: Hunger and Sex

This set of vocabulary flashcards covers concepts from the lecture on hunger, energy homeostasis, sexual differentiation, and the neurochemical control of behavior.

Nutritional homeostasis

Making sure the body has enough energy, but not too much

Prandial state

• After eating, blood is full of nutrients

Postabsorptive state

• while fasting (between meals) • Glycogen and triglycerides are broken down to provide energy (glucose), fatty acids, ketones

Anabolism

Creation of glycogen & triglycerides

Catabolism

Breakdown of glycogen & triglycerides

WAT (White Adipose Tissue)

• Energy storage • Hypertrophy (size) • Hyperplasia (#)

BAT (Brown Adipose Tissue)

• Only in mammals • Thermogenesis (keeps your organs warm)

Lipostatic hypothesis

brain monitors body fat and “defends” this energy store against perturbations (up or down)

Leptin

• Protein coded by the ob gene • Normally produced by WATs —> signals fat cells are present

Anorectic peptides

Peptides released by arcuate neurons, such as $\alpha\text{MSH}$ and CART, that decrease appetite.

Melanin-concentrating hormone (MCH)

• Prolongs consumption

Orexin (hypocretin)

• Promotes meal initiation

Ghrelin

released by stomach cells • travels via blood stream to hypothalamus • activates NPY/AgRP neurons in arcuate nucleus à increases hunger signals

Cholecystokinin (CCK)

• Released when food is present in small intestine (jejunum) • Biggest effects: fatty acids and proteins

GLP-1 (Glucagon-like peptide-1)

• Released when food is present throughout intestine • Biggest effects: carbohydrates, fiber

Dopaminergic system

Reward reinforcement and prediction • Dopamine encodes whether a stimulus is predictive of a good outcome

Sexual dimorphism

The difference in phenotype between the sexes of the same species, including differences in morphology, physiology, and behavior.

Organizational effects

• Permanent changes to physiology and behavior during development • Days, year

Activational effects

• Rapid, temporary effects regulating behavior • Seconds, minutes, hours, days

Aromatase

converts testosterone to estradiol

Oxytocin

Region- brain

Action- arousal, pair bonding

Vasopressin

A neurotransmitter implicated in pair bonding and the neurochemistry of mating systems.

Prolactin

Region- brain

Action- reward, then inhibition of motivation

Beige WAT

• Develops in WAT, but can also do thermogenesis

Humoral response

• via paraventricular nucleus of hypothalamus • increased secretion of TSH (thyroid-stimulating hormone) • increased ACTH (adrenocorticotropic hormone) • raise metabolic rate of cells throughout the body

Visceromotor response

• indirectly via paraventricular nucleus of hypothalamus & directly to Intermediolateral gray matter of spinal cord • increases the level of activity of the sympathetic division of the ANS • raises metabolic rate, raises body temperature

Somatic motor response

• via lateral hypothalamus • decreases feeding behavior